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TRMM Data Users Handbook

1. i ERBE like Geolocate ERBE like i INSTR BDS BDS Averaging to i k Bing CERES INSTR and Calibrate D cea EDDB Monthly TOA Instrument Earth Directional E Fluxes Data Scans ES4 ES8 ES Es4G MODIS CID Clear ES8 ES9 ES4 VIRS CID Reflectance ERBE ES4G Cloud Temperature Instan ERBE ERBE Imager History taneous Monthly Data SSF Single Satellite CERES Footprint TOA MWH and Surface Micro Fluxes Clouds wave SURFMAP Humidity SSF MWH APD 1 Compute SFC Hourly Regrid ps Surface and Gridded Single Humidity AED me Atmosphere Satellite TOA liative and Surface Hluxes Fluxes da GAP SE 5 Altitude SURFMAP i CRS ae CT Humidity Winds orm i Compute B CRS Singli P MOA 5 p Satellite Monthly and Meteorological ED URFMA gical Ozone Surface CERES Footprint Regional TOA Ozone Profile Radiative Fluxes and SRB Aerosol Data Data and Maps and Clouds Averages T CRS SRBAVG Grid Single SRBAVG GEO Satellite Monthly Geostationary Radiative Regional TOA Narrowband Fluxes and and Radiances Clouds SRB Averages 6 SURFMAP FSW FSW Hourly MOA GGEO Gridded Single Gridded GEO Satellite Narrowband Fluxes and Radiances Clouds T FSW GGEO Fat SYN Compute ANG AVG ZAVG atellites i Regional i j Synoptic gional Monthly Regional Time Radiative SYN Zonal and ZAVG x Zona and Global
2. nA x ws x new na x mus x x mus x necan To uh BE aaa nny s mea Way 3 EON ap x nex edd x Ju nomm p Figure 4 2 10 Data Format Structure for 2A25 6 3A25 PR Monthly Statistics of Rain Parameter The low resolution grid data of 3A25 are stored in the Planetary Grid 1 structure 5 x 5 and the high resolution grid data are stored in the Planetary Grid 2 structure 0 5 x 0 5 Figure 4 2 11 shows the structure of the 3A25 product in terms of the component objects and their sizes The Vgroups of PlanetaryGrid 1 and PlanetaryGrid 2 are Planetary Grid structure Section4 OUTLINE OF THE TRMM PRODUCTS ECS Core Metadata 10 000 bytes PS Metadata 10 000 bytes Date Granule PlanetaryGnd 1 Fields Omitted PlanectaryGrd 2 Fields Omitted Figure 4 2 11 Data Format Structure for 3 25 7 3A26 Monthly Rain Rate using a Statistical Method The 3A25 is grid data and it is stored in the Planetary Grid structure 5 x 5 Figure 4 2 12 shows the structure of the 3A26 product in terms of the component objects and their sizes BCS Core Metadata ILODI bates Data Granule PS Mitadata 1 000 bates SKM Taal Courts 4 byes Tua Cou abea Array ala x nhan Rain Counts Array miu x nh x nh Ze
3. rod de d e 2 18 Figure 2 4 1 TRMM Mission Operations Phases status as of pre launch ess 2 20 Figure 2 5 1 TRMM 24 Hour Operations nennen 2 22 Figure 2 5 2 Instrument Planning and Scheduling Operations serene 2 25 Figure 2 5 3 Cross track Antenna Pattern Measurement Calibration Timeline sess 2 21 Figure 2 5 4 Thermal Monitoring 2 28 Figure 2 5 5 CERES S cam Profile oen e ott ede tie 2 30 Figure 2 6 I Appearance of PR oscula t e eder re ie epe qo e esee eria 2 33 Figure 2 6 2 PR Functional Block Diagram 2 34 Figure 2 6 3 Measurement Concept of Precipitation Radar on board TRMM Orbit altitude 350 km 2 36 Figure 2 6 4 Transition of PR Operation Modes 2 38 Figure 2 6 5 The PR Subsystems and Components essere nennen 2 42 Figure 2 6 6 Antenna Subsystem Coordinate Axes sese neennen 2 44 Figure 2 6 7 Transition of 1 4 5 2 49 Figure 2 6 8 Operation of PLO when FCIF A System is turned on see 2 49 Figure 2 6 9 Function Systems relating to the Signal Intensity of the PR 2 51 Figure 2 6 10 Data Sampling Area during the Observation Mode Orbit altitude 350 km
4. sse 1 4 Table 2 1 1 Characteristics of the TRMM Satellite sees 2 1 Table 2 271 PR System Parameter Sissi oett Pete me doe e e em ER etes 2 11 Table 2 2 2 PR Antenna Subsystem 2 11 Table 2 2 3 PR Transmitter Receiver Subsystem Parameters 2 11 Table 2 2 A4 IML System Parameters uem erede PR T ER TER RD IER E e ete 2 13 Table 2 2 5 TMI Observation Characteristics 2 13 Table 2 2 6 TMI Observation Performance 2 13 Table 2 2 7 VIRS System 2 15 Table 2 2 8 VIRS Observation Performance 2 15 Table 2 2 9 CERES System Parameters rtr te tette tte terere e tet ripe rete nn 2 16 Table 2 2 I0 LIS System Parameters treten tret tete tr tee re e eit pe 2 17 Table 2 5 1 TRMM Operation Activities 2 21 Table 2 5 2 Spacectaft Maneuvets eraai yit eed este teer eee teet pepe ge eee engen 2 25 T able 2 5 3 PR Operational Modes nin de eret 2 27 Table 2 6 1 PR Subsystem and Component 2 32 Table 2 7 1 Comparative Table of Orbit Parameters before and after Orbit Boost 2 55 Table 2 7 2 Comparative Table of PR Characteristics before and afte
5. t i 1 st nach BEN Po ao he 1 1 i i 5096440 73 L 1 i i JAAD t yeu t 1 289gdung saug 291014 SSe pueg 1 uonpags E 615593024 901295 Jl vau NN Wee Aeusauog l i 1 i m Aouenbarj Jeydury eAuc 1014 Ssed pueg i i d t snaczepD 1 pod 1 j po i pog 2 7 1 ot domas L 1 VOL t BuissaooJg i van E AoJuo7 fouanbe 4 101190 Sanc mususi 3 uiejs g t i pog Fna B po wa Gare feos i VOL Q ill 1 I b DU i 1 geuuapry opinbaney l 1 VN ipod 9 t i Em iadwy OSON MOF go uto s sqnis ips D M I I 6 155 201 jeuDis i E 1 1 pes i 1 Ag spat 3 I De i C oi por RSS I i I 4 lors apinGaana walsksqng i NAM ror GAS 1 wejsAsqns r ieu am ia 1 uon pd muri t Iv4ss rm M Ht jo4u02 ueisAsqng i amp 16au l Qguuotu E anyon A amod EN Fa L 5 i waysAsqns t 1 BABII Es HUSBIL Hed euuatuy
6. eese eene eene nennen enne 6 6 6 3 Example of PR Output Product eene EE E 6 9 0 4 Utilization of TRMM Data osea etie eA AAU 6 12 0 22 IRMM EolloW On iiie E E URN NRBEM 6 17 APPENDIX Appendix 1 ACRONYMS AND enn een nn re netrennn es AI 1 Appendix 2 RELATED 2 1 CONTENTS List of Figures Figure 1 3 1 Tropical Rainfall and Climate Anomaly eese 1 3 Figure 2 151 5 2 toe 2 2 Figure 2 1 2 C amp DH Subsystem Block Diagram 2 3 Figure 2 1 3 ACS Block 2 4 Figure 2 1 4 Electrical Subsystem Block 2 5 Figure 2 1 5 Power Subsystem Block Diagram esses eerte 2 6 Figure 2 1 6 RF Communications Subsystem Block Diagram eese 2 7 Figure 2 1 7 Reaction Control Subsystem Block Diagram essere 2 8 Figure 2 2 1 Instrument Diagram e derer rere detener io o ne tue neenon 2 11 Figure 2 2 2 TMI Instrument Diagram sosite deeras sanaaa i aeaa Ena ae aa NE A TEL AMATE ARAE iTS 2 12 Figure 2 2 3 VIRS Instrument Diagram onein ne n a eao 2 14 Figure 2 2 4 CERES Instrument Diagrami sessar aeon aO PAE 2 16 Figure 2 2 5 115 Instrument Diagram 2 17 Figure 2 321 TRMM idt e toe
7. Combined Product using TRMM amp CHher data ads GMS or Gauge Figure 4 1 1 TRMM Algorithm Flow Diagram Section4 OUTLINE OF THE TRMM PRODUCTS 4 1 1 PR Data collected by the precipitation radar PR are processed from level 1 to 3 Processing carried out at each level is explained hereafter Also overall flow chart of the PR algorithm is shown in Figure 4 1 2 1A21 PR Echo Power Count Value Calibrated Received Power Hacaivad Power Noise Power Minimum Echo Flag Rain No Rain Flag Sidelobe Clutter Flag First Echo Range Storm Height Range Bin Number Surface Peak Clutter free Bottom T Bottom Top Mean of DID iri Ellipsoid factor with Hain Attenuation etc Normalized Radar Surface Cross Section c Normalized Radar Surface Qu alitative Cross Section Height amp Strength of Blight Band PIA Estimate Rain Type ale Warm Rain Rain No Hain Flag Freezing Height Storm Top Height 3D Hain Profile Hain Hate Profila Path Average Attenuation Corrected 7 Facter elc etc 3A25 Monthly Statistics of Rain Parameter Figure 4 1 2 Overall flow chart of precipitation radar algorithm Monthly Rain Rate using a Statistical Method TRMM DATA USERSHANDBOOK 4 1 1 1 Product Definition Types of data processed based on PR data are as follows
8. sd gy SA DAT aa ew Ajo WAIL L A do SIS GIASL u sdgIN 8 0 0 L LA UODEpIE A uap uiojyu Xoeqfe d Ppioosw preoquo AISSQ pu no 10 OOH mou 5 WAL TRMM Ground System Functional Diagram Figure 3 4 1 3 16 TRMM DATA USERS HANDBOOK 3 4 1 Mission Operation Center MOC The Mission Operations Center MOC operates under the Mission Operations and System Development Division MOSDD at the Goddard Space Flight Center GSFC and is the focal point for all TRMM on orbit operations control The TRMM is staffed 7 days per week 24 hours per day providing commanding health and status monitoring mission planning and scheduling network scheduling and coordinating functions for day to day spacecraft and instrument activities It provides the hardware and software systems necessary for the successful conduct of real time and off line activities From here the FOT ensures that spacecraft conditions are monitored and controlled and that science data capture is enabled The MOC facilitates TDRS scheduling and provides the appropriate interfaces to interact with the elements required to conduct mission operations The basic MOC functions are e Provide centralized mission planning coordination for the TRMM observatory e Provide real time observatory command uplink and verification e
9. t 12 pU o QD 13 UUN gt we Foc 4 4 4 nen ae 3 ms L Figure 4 1 17 Time integration at 700115 b Summary Data In the example data processing sequence just described there were fourteen events eight groups four flashes and three areas This example shows how the LIS algorithm will convert events into groups flashes and areas Some of the summary data statistics that would be generated from the LIS processing algorithm are shown in Table 4 1 7 areas Table 4 1 8 flashes and Table 4 1 O groups for this example During the LIS mission the start time is a relative time that will be counted from the beginning of each orbit Table 4 1 7 Resultant Area Data delta_time latlon count child count child id s Loa 0 7 e 2 700 A C child id s _ __ gt Section4 OUTLINE OF THE TRMM PRODUCTS 3 Algorithm Overview There are two major products produced by the LIS software a lightning data set and a corresponding background data set To obtain these data sets the satellite data stream needs to be decoded filtered clustered and output to the appropriate HDF file The function structure of LIS data processing software 1 shown in Table 4 1 10 Table 4 1 10 Function Structure of LIS Data Processing Software Item Task TRMM to Native The data is formatted to the TRMM standard and sen
10. x nlawer sfrramCOMB Ary lat x rain t MB 4 bytes x x nlayer sferain T Mloverlap 4 bytes x convert Rameverla Am nim x nlan sfceamC OM Boverlag 4 Array nlai x surf Army nia x surf Adj Ratowerlap Amay nlai x nlon Figure 4 2 18 Data Format Structure for 3B31 3 3B42 TRMM and IR Daily Rainfall The 3 42 is grid data and it is stored in the Planetary Grid structure 0 25 x 0 25 Figure 4 2 19 shows the structure of the 3B42 product in terms of the component objects and their sizes The following sizing parameter is used in describing this format nlat 400 the number of 0 25 grid intervals of latitude from 50 N to 50 S nlon 1440 the number of 0 25 grid intervals of longitude from 180 W to 180 E 4 90 TRMM DATA USERSHANDBOOK ECS Core Metadata bytes PS Metadata bytes Data Granule e Gridstructure SUDO bytes Precipitation 4 bytes Relative Error 4bytes Array nlat x nlon Array nlm x PlanetaryGrid Figure 4 2 19 Data Format Structure for 3B42 4 3B43 TRMM and Others Data Sources The 3B43 is grid data and it is stored in the Planetary Grid structure 0 25 x 0 25 Figure 4 2 20 shows the structure of the 3B43 product in terms of the component objects and their sizes The sizing parameter of 3B43 is same as 3B42
11. 35 Section3 OUTLINE OF THE GROUND SYSTEMS Processing Facility HK Data Verification Facility Data Processed Data Inspection Generation of standard product MVernfica tion Image display Reristraion of NAS As product Level Data Transmission of processed dats Data Orbit Data QL Data transmission plan Orbit Data E Calibration coefficient 1 d Management of orbit data Making of data transmission report request Management of MOG report lanag of report Scene info Making of QL processing request Precipitation radar Operation Planning Facility Figure 3 2 4 Operation Configuration Observation mode 3 2 1 Processing Facility 1 Outline The processing facility receives level 0 data sent from NASA via network Using this data it carries out internal calibration of the precipitation radar such as temperature characteristic correction and calculates the calibrated received power value and the radar reflectivity factor Z factor which indicates the reflection intensity of the raindrop particles to the radar wave PR Level 1 processing Furthermore it converts this radar reflectivity factor to a physical quantity such as rain rate PR Level 2 processing and once a month calculates the monthly precipitation for each specified grid of ground surface PR level 3 processing These products are distribu
12. unretrieved flag on interpolation or set the pixel to missing Within min RMS dev Output Vertical Structure Figure 4 1 9 TMI Level 2A 12 Process Flow Diagram 3 3A11 Processing a Objectives Objective of the algorithm for product 3A11 is to produce a monthly oceanic rainfall maps using TMI data for 5 x 5 grid which covers the area of 40 N 40 S x 180 E 180 W b Processing Description The microwave brightness temperature as observed from a spacecraft sensor is dependent upon the emission from the earth s surface and modified by the intervening atmosphere Hydrometeors are the main sources of absorption and scattering of microwave radiation in the ionosphere Over oceans the microwave radiation can be related to the rain intensity dynamic The histogram approach is based on the observation that rain rate can be modeled in statistics by a mixed distribution The mixed distribution consists of a discrete probability of no rain at zero rain rate and a log nominal distribution for the raining part Hence the parameters of the rain rate probability distribution function pdf can be related to the rain rate histogram 4 39 Section4 OUTLINE OF THE TRMM PRODUCTS c Input data For 3A11 processing brightness temperature data screen out the land pixel of 1B11 is input and the following reference data are used Land water mask data file The spatial resolution should be the same order
13. Scan Time 125 544 ms 1 650 ms 1 1 i 1to208 13 004 ms 2 For VIRS the following equation was derived from a viewgraph produced at Hughes and presented by Bruce Love on January 20 1995 T Scan Time 107 6 ms OFFSET 1 1 Sample Time where i 1 261 Sample Time 0 29157 ms and OFFSET values are shown in Table 4 2 3 4 77 Section4 OUTLINE OF THE TRMM PRODUCTS Table 4 2 3 OFFSET Values CHANNEL OFFSET The value of Sample Time was derived from the viewgraph using the time of the starting and ending channel 1 science data as follows Sample Time 183 7 ms 107 6 ms 261 3 For PR the following equation is reported T Scan Time 3 41 ms 1 1 x 11 768 ms where i 1 to 49 4 2 3 8 QAC Error Type This 1 byte of error information is produced at SDPF only for each packet for which an anomaly is detected This byte contains 8 fields shown if Table 4 2 4 each of which is a flag Table 4 2 4 Error Fields Bit Error Type 0 jJNoued S RS header errors Detected frame errors during the generation of this data unit 7 Data unit contains fill data 1 7 4 2 4 Structure of TRMM Data Products Structure of TRMM Data Products of PR TMI VIRS and COMB is explained hereafter For CERES and LIS refer to these documents Data Management System Data Products Catalog Algorithm Theoretical Basis Document CERES Algorithm Overview Al
14. c Output Data of 3A25 Processing As 3A25 output the following data is calculated in lon lat 5 x 5 and 0 5 x 0 5 region grid These grids cover the area of 40 40 S x 180 E 180 W and the number of grid is 16 x 72 for 5 x 5 and 148 x 720 for 0 5 x 0 5 a Probability of Rain Parameters Rain Pixel Number of observations for each grid at each layer and path rainPixl average with rain present Pixl is a rainfall observation frequency rainPix2 in 5 x5 grid Pix2 is in 0 5 x0 5 grid Stratiform Rain Pixel Same as the above but for stratiform rain stratRainPix1 Pix2 Convective Rain Pixel Same as the above but for convective rain convRainPix1 Pix2 Near surface Rain Pixel Number of rain observations at range gate nearest to surface rain surfRainPixl Pix2 certain only 4 24 TRMM DATA USERSHANDBOOK Stratiform Near surface Rain Pixel surfRainStratPix1 Pix2 Convective Near surface Rain Pixel surfRainConvPix1 Pix2 Surface Rain Pixel e surfRainPixl Pix2 Stratiform Surface Rain Pixel e surfRainStratPix1 Pix2 Convective Surface Rain Pixel e surfRainConvPixl Pix2 Warm Rain Pixel wrainPix1 Pix2 Shallow Rain Pixel shallowRainPixl Pix2 Shallow Isolated Rain Pixel shallowIsoRainPixl Pix2 Total Pixel ttlPixl Pix2 Bright Band Pixel bbPixNuml Num2 Convective Rain epsilon Pixel epsilonConvPix1 Pix2 Stratiform Rain
15. 1 PR Level 1 processing In PR Level 1 processing Level 0 transmitted from NASA data is checked whether it is in an observation mode and then three types of products are processed which are 1A21 1B21 and 1C21 Moreover received power noise level Z factor including rain attenuation is calculated However 1 21 is actually processed within a same routine as 1B21 so 1A21 itself is not singly output 2 PR Level 2 processing In PR Level 2 processing three types of products are processed which are 2A21 2A23 and 2A25 based on result of Level 1 processing and several kinds of quantitative qualitative parameters are calculated such as height of the bright band normalized radar surface cross section rain type Z factor correcting rain attenuation 3D profile of rain rate and others 3 PR Level 3 processing In PR Level 3 processing two types of products are processed which are 3A25 and 3A26 based on the result of level 1 and 2 processing and monthly averaged rain rate is calculated for the longitude 5 x latitude 5 grid mesh In the 3A25 moreover 0 5 x 0 5 mesh monthly averaged rain rate is calculated for user s convenience 4 1 1 2 Outline of Processing Algorithm Outline of each processing algorithms are as follows The structure of each product except 1A21 is described in the later section 4 2 4 1 The detailed explanation of PR processing algorithm and output parameters is shown in the document Tropical Ra
16. E ede Re ea 4 79 LALA TMT raa andi idem 4 84 42 4 37 MARS ede pude p re Hp Sa GLAST a Lae re dr 4 87 COMB ied reet ERU SU ARES RESI avons FOTOS YU AGUNT 4 86 4 57 Tool Kits eoe tpe mene ni he RGA 4 92 31 4 93 43 2 GORVerston LoOoDKIt soir ta E et D ita t t d er 4 95 43 3 Geolocation TOOL 4 96 SP 4 96 23 EOISSDATA SERVICE 5 1 5 1 Outline of EOIS SErVICOS 5 1 5 2 Catalog Information Service 5 3 5 2 1 Inventory Information Service eese 5 3 3 22 Image Catalog iic 5 3 5 3 Data 5 4 2 9 Ordering of TRMM Data essit e ee e oU OUR TED Pei Sedes 5 4 53 2 Data Providing Flows eee vet ee RI M ERE EGS 5 6 5 3 3 TRMM Distribution Medi a aet eee E pe eee rice erts 5 7 5 3 4 Online Distribution ie bere Pee Ode s eres 5 8 53 5 Sample Data Distributions estet esee ere e e e e eg UR RE WR 5 8 TRMM OPERATION STATUS RESULTS and FUTURE PLAN sse 6 1 6 1 On Orbit Initial Check out Result eese eee eene nnne enne nnne enne nter nenne 6 3 6 2 PR Calibration and Validation Result
17. HP Hewlett Packard Co NICT National Institute of Information and HYB Hybrid Communications technology I NMS Network Management Subsystem ICS Interface Control Specification NOAA National Oceanic and Atmospheric IFOV Instantaneous FOV Administration IMS Information Management System NASA NS Noise Source INT Integration NUBF Non Uniform Beam Filling IOA Initial Orbit Acquisition IP Internet Protocol OLIS On Line Information System IPSDU Instrument Power Switching and OSR Optical Solar Reflector Distribution Unit OTD Optical Transient Detector IR Infrared P IRS Information Retrieval System PBIU Power Bus Interface Unit IRU Inertial Reference Unit PC Personal Computer ISCCP International Satellite Cloud Climatology PCM Propellant Control Module Project PDB Project Data Base ISO Isolator PGS Product Generation Service J PHS Phase Shifter JAXA Japan Aerospace Exploration Agency PI Principal Investigator JPEG Joint Photographic Coding Experts Group PLO Phase Lock Oscillator JFIF JPEG File Interchange Format POD Project Operations Director JMA Japan Meteorological Agency PR Precipitation Radar JPL Jet Propulsion Laboratory Pulse Repetition Frequency L PRI Pulse Repetition Interval L amp IOC Launch and In orbit Checkout PROP Propagation LAN Local Area Network PS Pointing System LaRC Langley Research Center NASA PS Product Specific metadata LHCP Left
18. have used the term flash for this data category because we believe that as it has been defined above the resultant flash will generally correspond to the accepted definition of a conventional lightning flash Note that with LIS data alone we cannot determine if a flash is a ground or cloud flash It is possible that future versions of the LIS algorithm may incorporate data from ground flash locating systems to help interpret LIS flashes We do acknowledge that on occasion distinct conventional lightning flashes may result in a single flash being produced by the LIS algorithm e g possibility in high flashing rate mesoscale convection systems Other mismatches between algorithm flashes and actual conventional flashes will undoubtedly also occur Note that there is no absolute time limit to a flash That is as long as subsequent groups are produced in an area within the 330 ms time windows all groups will be assigned to a single flash e Area Lightning is produced in thunderstorm cells that have dimensions of about 10 km by 10 km Many storms however are multicellular and may extend over large areas and exist for many hours Individual storms generally last much longer than the LIS will view them Therefore we define an area as a near contiguous region on the surface of the earth that has produced lightning defined as a set of LIS flashes during a single orbit of the LIS An area thus defined consists of a set of flashes separated
19. pe Sorina Sage Cakubiten of Kedar Ecibcctrerte incl Hain Aue rar inn Rang Hin Mimbar of Figure 4 1 8 Relationship between functions of 1C21 processing 4 2 21 Processing a Processing Description 2 21 processing is to read the result of 1B21 processing and to calculate instantaneous value and time and spatial average reference data of ground surface scattering coefficient It is the same as normalized Scattering Radar Cross Section of the Surface from radar received power There are two methods to calculate time and spatial average In a method gridding ground surface 0 1 x 0 1 area and collecting scattering coefficient data that IFOV is within each area from which are calculated the time average for every month time averaged reference data As the another reference date scattering coefficient data over no rain area are collected for 8 scans of the same angle bin just before rain area along with the satellite pass and their average are calculated for every angle bin spatial averaged reverence data The reference data that 1s smaller standard deviation is selected from time averaged reference data and spatial averaged 4 15 Section4 OUTLINE OF THE TRMM PRODUCTS reference data with the satisfactory restriction for the number of independent samples more than 50 for time averaged reference data more than 8 for spatial averaged reference data For Version 6 Hybrid Tech
20. 2 CERES LIS products are deadly copied in the unit of NASA providing products 8 mm tape 3 8 mm tape or CD ROM or DVD or DLT are selectable as a distribution 4 Generation of products for standing order depends on arrival date of master data and assumes mass production so it is pre scheduled 5 The version to be specified by an order or latest version of master data is adopted for product generation Table 5 3 4 List of TRMM Distribution Media PR OK OK OK OK OK OK CK OK OK CK OK OK OC J OK J MES ox OK ox OK OK OK OK j OK OK OK CERES Mrs 3px s p sz us one qoo qnos E s OK Selectable Not available Available only for 1 Day data of PR 2A25 full scene 57 Section5 EOIS DATA SERVICE 5 3 4 Online Distribution Registered user can obtain processed data via the Internet by specifying On line delivery when the user submits an order with the scene ordering or data set ordering option This service is available only to registered users and not available to general users Registered user can confirm whether or not the product is ready to download on the Order status result screen If On line button is displayed on the record the product can be downloaded 5 3 5 Sample Data Distr
21. 2 52 Figure 2 6 11 Data Sampling during External Calibration Mode Orbit altitude 350 km 2 52 Figure 2 6 12 Coordinates Axes of the Satellite and PR sesesssssssseeeeeeeenenene 2 54 Figure 2 6 13 Scan Irack or PR ooa ione merde 2 54 Figure 3 1 1 TRMM Total Ground System oo ao aaa raaa 3 2 Figure 3 2 1 Relationship between the TRMM PR Data Processing System and Foreign Organizations 3 3 Figure 3 2 2 Overall Structure of the TRMM PR Data Processing System sse 3 4 Figure 3 2 3 Software Structure of the TRMM PR Data Processing System esee 3 5 Figure 3 2 4 Operation Configuration Observation mode 1 3 6 Figure 3 2 5 Appearance of Precipitation Radar Calibrator esee 3 9 Figure 3 3 1 System Overview of EOIS DDMS 3 10 Figure 3 4 1 TRMM Ground System Functional 3 16 Figure 4 1 1 TRMM Algorithm Flow 4 3 Figure 4 1 2 Overall flow chart of precipitation radar algorithm seseseeeeeeeeene 4 4 Figure 4 1 3 Function structure 1A21 processing eeesseseeseeseeseeeeeeeeeennennen eere nennen etre nen 4 7 Figure 4 1 4 Relationship between functions of 1A21 processing sess 4 7 Figure 4 1 5 Function structure of 1B21 processing 1 4 12 Figure 4 1 6 Relationship between the functi
22. E Teha of inns and chars Figure 4 2 1 Primary HDF Data Structures HDF is more than a file format It also consists of supporting software that makes it easy to store retrieve visualize analyze and manage data in HDF files HDF can be viewed as several interactive levels as illustrated in Figure 4 2 2 senenil Applicurins Lars F MESA F L orurmencul Ap comes angle File Multi File amp 1 i Pairi A niodo Fil Master F Fii Kier 1 warmipa A Leones r unis E M p Lu p zl Lass feel bnterface y HIZHX Enierface Imenice HDF File Healer F Piescnpier Akk F Dain Fleme nis Figure 4 2 2 The Three Levels of Interaction with the HDF File Format At its lowest level HDF is a physical file format for storing scientific data At its highest level HDF is a collection of utilities and applications for manipulating viewing and analyzing data in 468 TRMM DATA USERSHANDBOOK HDF files Between these levels is a software library that provides high level APIs and a low level data interface The basic interface layer or the low level interface is reserved for software developers It was designed for direct file I O of data streams error handling memory management and physical storage It is essentially a software toolkit for skil
23. Schedule Managerrent System Data Processing bsyst Subsystem Inforrration Retrieval _Inforrration Service System Subs E Data Generation System Data Storage System Figure 3 3 1 System Overview of EOIS DDMS 3 10 TRMM DATA USERSHANDBOOK 3 3 1 Data Distribution and Management System The DDMS is composed of the subsystems shown in Table 3 3 1 Table 3 3 2 shows the outline of the function of each subsystem Table 3 3 1 Subsystems of DDMS JAXA Earth Observation data and Information System Data Distribution Management System Data Generation System Media Conversion Subsystem Data Storage System Schedule Management System Schedule Management Subsystem SMSS Information Retrieval Subsystem IRS Catalogue data Distribution System CADS Browse data Distribution Subsystem BDS On Line Information System Data Distribution Subsystem Network Management Subsystem Information Service System ISS Section3 OUTLINE OF THE GROUND SYSTEMS Table 3 3 2 Function of DDMS System Subsystem Function Data Media Conversion Copy processed data onto distribution media for Generation Subsystem users System Data Storage System Store and manage satellite data in a readable form Schedule Management Input and edit order information and manage Schedule Subsystem transport of deliverables Management _ ONE
24. x nmecan nray x nscam 2 fray x necan 2 x nray x nscan 140 x nray x nscan 5x 29 x nscan 2 11 x nascan The 1C21 has the same format as 1B21 with 3 changes The variable in the Normal Sample TRMM DATA USERSHANDBOOK Surface Oversample and Rain Oversample is reflectivity dBZ in 1C21 3 2A21 Normalized Radar Surface Cross Section The 2A21 is stored as a Swath Structure in HDF Figure 4 2 8 Data shows the structure of the 2A21 product in terms of the component objects and their sizes ECS Core Metadata 10 000 bytes FS Metadati IDODI babes kwath Structure S000 bytes Table scan Data hen Time colocation 4 bytes Array x may x nscan Scu Statws 19 bytes Table nscam Table nscam Sigma zera Array mnray x mecan SwathData Path Attenuation Array ney x Fines Arr nra x mecan Reliability Factor Array nray x meran Incident Angle Army nray x Tecan Rain Flag Arrav x decur Figure 4 2 8 Data Format Structure for 2A21 4 2A23 PR Qualitative The 2A23 is stored as a Swath Structure in HDF Figure 4 2 9 shows the structure of the 2A23 product in terms of the component objects and their sizes Section4 OUTLINE OF THE TRMM PRODUCTS ECS Core Metadata 10 000 bytes PS Metadata 10 000 bytes Table nscan Anay npeo x necan Table Navigation 88 bytes Table nscan
25. Array nray x mecan Array nray x necan Array mray necan 2 Array E Array nray x nray x Array nray x x Array x Array nray x Array x Array nray x necan Array x necan Data Granule Swath Data Figure 4 2 9 Data Format Structure for 2A23 5 2A25 3 Rain Profile The 2A25 is stored as a Swath Structure in HDF Figure 4 2 10 shows the structure of the 2A25 product in terms of the component objects and their sizes ECS Core Metadata 10 000 bytes PS Metadata Data Granule Table 49 General 10 000 bytes Convective 10 000 bytes Stratilorm 10 000 bytes Other 10 000 bytes Swath Data See diagram continued on next page for Swath Data TRMM DATA USERSHANDBOOK Cou Cree 54g dixgram ea previous pags For Dara Granglej Seah recu ED X rogii s oy HB amp Pig neal amp rrxy ret amp mcam Dad amp wy ipia x way ene Amp ned rip red a pray nes I II x mip Duy E 5 um s lxwuy x maa an Precig War Sami peus nra Fichas Fg lhykm Are rry ru
26. Swill Structure SEKI bytes Sean lime 5 bytes Table nacan Geoloeation bytes Arrav 2 npixel x macai Scan Valata Table nscan Scan SDS Armay Y x necan FOV SDS Array Y x npixel macan Figure 4 2 3 Generic Swath Structure The purpose of the SwathStructure is to allow EOSDIS to ingest data into their archive therefore the Algorithm Developer will not need to read or write the data contained within this object SwathStructure is an object that mimics an attribute since HDF has not yet defined attributes for Vgroups This imitation of an attribute is implemented as a single Vdata with the name SwathStructure the class Attr0 0 one field named VALUES number type of DFNT_CHARS and order equal to the length of the text This specification of SwathStructure anticipates the HDF development of attributes for Vgroups The maximum expected size for SwathStructure is 5000 bytes 4 2 2 2 Planetary Grid Structure The Planetary Grid Structure is a structure created by EOSDIS to store earth located grids The grid is an array of grid boxes rather than grid points TSDIS employs the Planetary Grid Structure in Level 3A and 3B satellite products Figure 4 2 4 shows a generic Planetary Grid 4 70 TRMM DATA USERSHANDBOOK Structure as it is used in TSDIS formats The Planetary Grid Structure occupies part of a file This structure is contained in a Vgroup with the name PlanetaryGrid and the class
27. 0 10 1 1 1 100 50 0 50 100 Crosstrack direction Figure 2 6 13 Scan Track of PR 2 54 TRMM DATA USERSHANDBOOK 2 7 Operation of Post Orbit Boost 2 7 1 Background Since launch TRMM is continuing the operation in a good condition and the operation for about six years was expected based on the fuel consumption in routine operation period However based on the estimate of necessary fuel to control reentry changed a lot the estimate of its operation period was corrected to about four years and a half see the section 2 4 Therefore and NASA decided to raise the satellite altitude from 350 to 402 5 km in order to extend its mission life As the result mission life of TRMM is expected to expand around few years although it depends on solar flux activity 2 7 2 Change of Orbit Parameter Due to change of orbit altitude to 402 5 km orbit parameters of TRMM are slightly modified The modification points are listed in table 2 7 1 Table 2 7 1 Comparative Table of Orbit Parameters before and after Orbit Boost Pre Boost Post Boost Altitude 350 km 402 5 km Perigee Apogee Height 347 6 354 8 km 399 7 407 2 km after AV maneuver Period 91 5 min 92 5 min Ground Speed 7 3 km s 7 2 km s Argument of Perigee 100 deg 100 deg Attitude Control ESA Kalman filter with DSS IRU and Earth Sensor Asse
28. 32 Range bin a Number of range bins 400 b Range bin intervals 125m 1m 33 Scan angle bin a Number of scan angle 103 b Scan angle bin intervals 0 355 0 1 2 6 4 Outline of the Operation As an outline of the operation the observation principle and observation method are described as follows The principle of precipitation measurement using a radar makes use of radio waves When radio waves are emitted from a radar they are scattered by the raindrops and a portion return in the direction of the radar backscattering Amount of precipitation is estimated based on the relational expression radar equation that is established between the energy intensity of scattered waves received power strength and rainfall intensity that are received by the radar antenna There are a number of presumed conditions placed on the radar equation such as the 3 Excludes error caused by rainfall and atmosphere attenuation Excludes error caused by statistical variation for each pulse in the radar reception level This provision is applied to the signal level within the dynamic range provided in 16 2 40 TRMM DATA USERSHANDBOOK diameter of the raindrops are small enough compared with the wavelength of the radio wave used 5 m raindrops are distributed evenly within the radar beam the descending speed is constant and so forth Accordingly correction is carried out as necessary The precipitation radar transmits pulse w
29. 51 Section5 EOIS DATA SERVICE 2 Image Catalog Data Search By searching for image catalog data of a standard product display the image Use the following options to display an image Addition to the options listed above user can use his own viewer and print image catalogs by using the customize function later described 3 Map Display Display a world map or a map for Japan and draw various search results about coverage for each scene Users can select the Lambert Conformal Conic Projection and the Polar Stereo Projection as the map projection Draw the following information Inventory search results Observation request positions Specified areas on a map etc 4 Ordering Request Available only for permitted users Order standard products based on the result of catalog information search You can send the order to the server by online and also print it out as an order sheet 5 Request Status Search Search for the status information that indicates how your ordering request is accepted or how much progress the process has made 52 TRMM DATA USERSHANDBOOK 5 2 Catalog Information Service 5 2 1 Inventory Information Service Catalog information about standard products processed at the TRMM Data System is produced and provided to users TRMM inventory information managed and provided by EOIS is shown in Table 5 2 1 Users can also retrieve catalog data processed by the NASA TRMM Science Data Informa
30. Data Format Structure for eet pee tee Oe reo reds 4 91 Sample Display of Orbit Viewer 4 97 Example of Order Sheet for TRMM PR scene order sss 5 6 Diagram of order flow from request to 15101 5 7 PR incer C 6 4 Cross Calibration between TRMM PR and Ground Radar at Ishigaki Island 6 7 Example of Such a Simultaneous Observation by TRMM PR and CAMBR 6 8 Distribution Pattern of Radar Reflectivity 2A25 sess 6 8 Example of PR Output Product 1B21 1C21 and 2 25 1 6 10 Example of PR Output Product 2A23 issssesssssseseeeeseeeeeeenen eerte nentes 6 10 Example of TRMM Level 3 Monthly Rainfall Products May 2000 6 11 Rainfall Distribution in January 1998 and 1999 6 12 Sea Surface Temperature from 1 6 13 Rainfall Observation Result from VIRS TMI ene 6 14 Soil Wetness Estimated from 6 15 Long wave TOA Flux from CERES ERBE like Processing eee 6 16 Total Number of Lightning Flashes essent 6 17 CONTENTS List of Tables Table 1 4 1 Responsibilities of US and Japan related to development and S C operation 1 4 Table 1 4 2 Responsibilities of Japan and US related to data processing
31. In addition the SDPF generate format and transmit accounting and data quality information to data users The SDPF makes Level 0 processed data sets available for delivery to the TSDIS LaRC MSFC and JAXA EOC within 24 hours of receipt of a full 24 hour data set and will store the raw data 2 years Level 0 processed data contains all telemetry received in a 24 hour period sorted by Application Process Identification APID and time ordered with redundant packets removed The SDPF also delivers Quicklook data sets containing specific packets acquired during a single TDRS contact In addition to data processing the SDPF is responsible for distributing definitive and predictive orbit data received from the FDF to the facilities of NASA and JAXA 3 18 TRMM DATA USERS HANDBOOK 3 4 0 TRMM Science Data and Information System TSDIS The TRMM Science Data and Information System TSDIS operates under the Global Change Data Center at GSFC Its primary function is to process rainfall instrument science data from the TRMM spacecraft and data from the Ground Validation GV sites and distribute the products to TRMM science algorithm developers scientists performing data quality control and TRMM instrument scientists The processing of TRMM Level 0 data to generate Level 1 products is based on algorithms provided by the TRMM instrument scientists TSDIS develops Level 1 processing software for the TRMM Microwave Imager TM
32. activities for TMI will be incorporated only after an instrument activity request has been submitted Figure 2 5 2 shows the above mentioned instrument planning and scheduling operations and Table 2 5 2 shows the TRMM spacecraft maneuvers The TRMM Science Data and Information System TSDIS SOCC will assist with the planning and scheduling operations for the three rain instruments PR TMI VIRS The FOT will provide planning and scheduling of CERES and LIS activities for the LaRC and MSFC instrument facilities Observatory planning results in the generation of a DAP This plan contains the observatory commands required for a single day s operations Once a DAP is generated and a confirmed TDRS schedule from the Network Control Center NCC are in the MOC constraint checking modeling and load generation for a given day s operations can begin Another major activity conducted in preparation for TRMM operations is SN contact scheduling This process begins approximately three weeks prior to the operational period when orbital data products are received from the FDF The FOT s interface with the NCC is via the User Planning System UPS which provides automated schedule generation and electronic communications for exchanging TDRS schedule requests and confirmed schedules 2 24 TRMM DATA USERSHANDBOOK Time in Advance PR VIRS TMI Spacecraft Activities CERES LIS 4 weeks requests from 9 requiring S C Activiti
33. and has shifted to the post operation phase Previously it was expected that it could be operational until end of 2003 based on the remaining fuel dated end of 2000 But currently mission life of TRMM is expected to extend until September 30 2009 for the time being due to orbit boost in August 2001 4 End of Life Ocean Disposal Phase The end of life ocean disposal phase is the final phase of the mission Because TRMM is a low altitude 350 km x 1 25 km satellite the main issue for normal operation is maintaining its orbit TRMM was launched with approximately 890 kg of hydrazine load Previously the decision to 2 19 Section2 OUTLINE OF THE TRMM SATELLITE terminate the mission was made when the remaining fuel reached approximately 58 kg But currently it became clear that about 157kg fuel was necessary for control reentry based on the re analysis performed during the shift to extended operation phase However reexamination by NASA derived that 138kg of fuel would suffice for the control reentry After that although the remaining fuel was at 138kg in September 2005 JAXA and NASA decided to continue the mission until September 30 2009 for the long term scientific achievements of TRMM instead of the ocean disposal phase SIC Checkoat Sdays Soi Wo ee Re ee E C oce 40 Day Instrument Descent Tam On amp Functional Checkoat Minati a E MN 360 km 3 year Science Mission eck aa tas es A a A
34. because an anomaly occurred on the power source of data collection system DAA of CERES in August 1998 Moreover CERES operation was completely terminated since May 29 2001 2 2 4 2 System Parameters Figure 2 2 4 provides a graphical description of the CERES instrument diagram Table 2 2 9 provides system parameters Figure 2 2 4 CERES Instrument Diagram Table 2 2 9 CERES System Parameters Observation Band 0 3 5 um short Wave Channel 8 12 um Long Wave Channel 0 3 gt 50 um Total Wave Channel Horizontal Resolution 10km nadir Swath Width Scan Angle 82 deg Cross Track Scan or Biaxial Scan TRMM DATA USERSHANDBOOK 2 2 5 Lightning Imaging Sensor LIS 2 2 5 1 Mission Overview The LIS is an optical staring telescope and filter imaging system that acquires and investigates the distribution and variability of both intracloud and cloud to ground lightning over the Earth The LIS data also is used with PR TMI and VIRS data to investigate the correlation of the global incidence of lightning with rainfall and other storm properties The data from the LIS instrument can be correlated to the global rates amounts and distribution of precipitation and to the release and transport of latent heat LIS 1 a single string instrument with multiple single points of failure The LIS instrument was powered ON during the initial instrument activation and remains powered in that configuration for the duration of
35. 2 System Information Retrieval Register and manage receiving information and Subsystem processing information Catalogue Data Browse data Distribute browse data to users by a network Distribution Distribution System Subsystem Data Distribution Exchange data by network with data centers such as On Line Subsystem NASA and data utilization organizations Information Network Management Monitor the network load of the Data Distribution System Subsystem Subsystem manage the network security and manage network users Information Service System Offer indication of an image and a map and order service with on line 3 12 TRMM DATA USERSHANDBOOK 3 3 2 Data Generation System 1 Media Conversion Subsystem The Media Conversion Subsystem is the system to copy processed data from the Data Storage System onto distribution media for users The subsystem also has the format conversion function to extract part of image rearrange pixel distribution and output some kinds of data formats such as Skinny CEOS etc 8mm CD ROM DLT and DVD can be selected as the distribution media of TRMM data and only HDF format is applicable see Table 5 3 4 2 Data Storage System The Data Storage System is the system to store and manage satellite data in a readable form It will transmit requested data via LAN based on the request from the Media Conversion Subsystem the Information Service System etc Depending
36. 2 6 6 Observation Model 2 6 6 1 Radiometric Model The mathematical model seeking the equivalence radar reflectivity factor Zm and the normalized scattering cross section o at the ground surface from precipitation reflection power data is described in Section 4 1 1 Function systems relating to the signal intensity of the precipitation radar system are shown in Figure 2 6 9 RAIN EARTH L EZwo L Lp Gr NOTE TX Transmitter ANT Antenna PROP Propagation REF Reflection NS Various Noise Sources RX Receiver Figure 2 6 9 Function Systems relating to the Signal Intensity of the PR system 2 6 6 2 Observation Range Model Outline of the observation area is shown in Figure 2 6 10 during observation mode and Figure 2 6 11 during external calibration mode Both figures show only half of the scan range In the observation range model for post orbit boost distance between satellite and range bin number 1 is changed from 327 km to 379 5 km In fact it means that the observation point shifts by one pulse approx 54 km After orbit boost moreover number of range bin in the angle bin 1 2 3 4 46 47 48 49 increases respectively 6 4 3 1 1 3 4 6 1 range bin 125 m 251 Section2 OUTLINE OF THE TRMM SATELLITE TRMM Satellite Precipitation echo Reference point of the range Bl Surface echo over sample 327 km II Rain over sample NB The area sampled
37. A a onm umm E xu 350 km Jj 125 km Drag Down O Pbase 2 se ts lt Ascent Re entry Maneover Pre Launch Launch amp S A End of Life Planning and In Orbit Normal Mission Operations Ocean Disposal Testing Checkout MISSION PHASE Figure 2 4 1 TRMM Mission Operations Phases status as of pre launch 2 20 TRMM DATA USERSHANDBOOK 2 5 Spacecraft and Instrument Operation The normal mission operations consists of maintaining spacecraft and instrument health and safety providing routine control of the spacecraft and instrument systems and collecting science data The Flight Operations Team FOT is responsible for monitoring observatory health and safety and providing routine spacecraft control The science facilities are responsible for ensuring that science objectives are met and for monitoring and maintaining instrument performance The FOT will ensure safe observatory operations based on requests from the Mission Operations Center MOC 2 5 1 Spacecraft Operation The TRMM on orbit operation activities are summarized in Table 2 5 1 The typical operation profile for 24 hours is shown in Figure 2 5 1 Table 2 5 1 TRMM Operation Activities Summary Attitude Control System Acs AV Maneuver Every 7 to 30 Days Definitive Orbit Once per Day ACS Performance Monitor Every R T Contact Every R T Contact P
38. COMB Combined GDS Ground Data System COMETS Communications and Broadcast GEO Geostationary Engineering Test Satellite Global Energy and Water Cycle Experiment CRC Cyclic Redundancy Code GMS Geostationary Meteorological Satellite CRL Communications Research Laboratory GN Ground Network Currently named GOES Geostationary Operational Environment CRS Cloud Radiative Swath Satellite CSS Coarse Sun Sensor GPCP Global Precipitation Climatology Project D GPI GOES Precipitation Index DAAC Distributed Active Archive Center GPM Global Precipitation Measurement NASA GRS Global Reference System DAO Data Assimilation Office GSACE Gimbal and Solar Array Control Electronics DAP Daily Activity Plan GSFC Goddard Space Flight Center NASA DAS Data Analysis System JAXA GSTDN Ground Station DDMS Data Distribution and Management GUI Graphical User Interface System JAXA GV Ground Validation DDS Data Distribution Subsystem H DGS Data Generation System HDF Hierarchical Data Format DIV COMB Divider Combiner HGA High Gain Antenna DMR Detailed Mission Requirements HGADS High Gain Antenna Deployment System DSN Deep Space Network HGAS High Gain Antenna System DSS Data Storage System HK Housekeeping 1 1 Appendix 1 ACRONYMS AND ABBREVIATIONS
39. Monthly 53 KB 3A11 Monthly Oceanic Rainfall Grid 5 x 5 30 40 KB VIRS 1B01 Radiance 1 orbit 16 day 1 185 2B31 Rain Profile 1 orbit 16 day 7 10 MB Global Map Monthly 442 KB 3B31 Monthly Rainfall Grid 5 x 5 380 410 KB Daily Rainfall Grid 0 25 x 0 25 250 350 KB TRMM amp Other Sources Global Map Monthly Monthly Rainfall Grid 0 25 x 0 25 4 6 5 0 MB 1 1 orbit defined from the south end to next south end of each orbit In almost cases TRMM product of which scene unit is one orbit is prepared 16 times in a day But it is occasionally 15 times in a day 2 Estimated data volume shown in the above table is corresponding to the version 6 product It may be changed due to algorithm version up Moreover Compression is applied as compress method of each product 42 TRMM DATA USERSHANDBOOK Laval 1B 1801 1811 1821 Calibrated Ried ved Pawar 1C21 PH Radar ty Level 2 i PR Qualitat ve 2 12 i Rain Profile PR 30 Rain Profile 2831 Level 3 3A11 3831 25 3AZ6 TMI En PR PR Doni rental Monthly Frain tril esp a nein M eec tere aun Level 3 nt 3B4 1 A Pi Global Precipitation index Daily FHainifall CAR rre Auer and boning System GPCC Global Pnecipitatian 18473 Gimalolagy Cenber Moniy Hana TRAM amp iher Sources A
40. PlanetaryGrid In that Vgroup appear one GridStructure one or more Data Grids and other Data GridStructure is a single Vdata which allows the geometric interpretation of the grids GridStructure is an object that mimics an attribute since HDF has not yet defined attributes for Vgroups This imitation of an attribute is implemented as a Vdata with the name GridStructure and the class Attr0 0 one field named VALUES number type of DFNT CHARS and order equal to the length of the text This specification of GridStructure anticipates the HDF development of attributes for Vgroups The maximum expected size for GridStructure is 5000 bytes Since the purpose of GridStructure is to allow EOSDIS to ingest data into their archive Algorithm Developers do not need to read from or write to GridStructure Figure 4 2 4 specifies the fields within GridStructure Six of the fields the resolutions and bounding coordinates are also found in Core Metadata Three fields bin meth registration and Origin are not found in Core Metadata jts Tahle Daian Conil y x nlai s min X is he sine of ene clemen abd Y isa dimension size Figure 4 2 4 Generic Planetary Grid Structure Table 4 2 1 GridStructure Fields bytes bin meth 50 Method used to obtain the value in the bin A simple mean would have the value ARITHMEAN Currently no other values have been defined re
41. Reliability Factor Sigma Zero lt from 2A23 gt Rain Type Shallow Rain Processing Status Height of Freezing Level Height of Bright Band c Output Data of 2A25 Processing The outputs of 2A25 processing are listed in below Clutter Flag CLUTTER FLAGS The clutter information in the Ray header of 1B21 Main lobe Clutter Edge Absolute value of the difference in Range bin Numbers between the detected surface and the edge of the clutter from the main lobe Side lobe Clutter Range Absolute value of the difference in Range Bin Numbers between the detected surface and the clutter position from the side lobe 421 Section4 OUTLINE OF THE TRMM PRODUCTS Rain Attenuation Parameter a attenParmAlpha Rain Attenuation Parameter attenParmBeta Parameter Node parmNode Corrected Z Factor dBZ correctZFactor Epsilon epsilon Epsilon 0 _0 epsilon 0 Error Estimate of Rain dB errorRain Error Estimate of Z Factor dB errorZ Estimated surface Rain e SurfRain Height of Freezing Level m freezH Method method Near Surface Rain Rate nearSurfRain Near Surface Z Factor nearSurfZ NUBF Correction Factor nubfCorrectFactor PIA dB pia Attenuation parameter alpha of relationship equation between attenuation coefficient and Z factor k aZeP alpha is given at five nodal points and alpha values between the nodes are calculated
42. Specify only when ordering sub scene 3 Specify only when ordering multi file group 4 Choose only when ordering PR 1C21 and or 2A25 5 Code based on media and data formats 5 5 Section5 EOIS DATA SERVICE Table 5 3 3 Items to be specified for Standing Order _________ Ne Ending date of a providing product Choose data unit from 1 day 10 day or 1 month Product version Specify product version latest version in case of no selection E Essential item requires to be specified O Optional item to be specified For CERES and LIS no choice except Observation data and processing level 1 Specify for which of range of sub scene number or lat lon range of sub scene when ordering sub scene 2 Choose only when ordering PR 1C21 and or 2A25 3 Choose only when ordering PR 2A25 full scene For other products being fixed to month of calendar 10 day or 1 month order is selectable under a specific contract with NASDA 4 CD ROM is available only for 1 day product of PR 2A25 full scene 5 Code based on media and data formats Sub No Satellite Sensor Observation Date Processing Level Name of Data Set Tl PR 1B 1C 2A 3A 21 23 25 26 Multi File Group Type Full scene Scene Number Sub scene Number for sub scene order of Fixed region Ordering within Scene Group Sub scene Media CD ROM 8mm DVD DLT Online Data Code Quantity of Order Comments F
43. System 1 Data Distribution Subsystem The Data Distribution Subsystem is the system to exchange data by network with data centers such as NASA and data utilization organizations 2 Network Management Subsystem The Network Management Subsystem is the system to monitor network load of the Data Distribution Subsystem and manage the network security the log information and the network users It also has the function to detect a problem on network determine its cause and control the problem 3 3 6 Information Service System The Information Service System is the system offering service such as search raster display map indication an order for data by catalogues A user can use this system on the Internet 314 TRMM DATA USERS HANDBOOK 3 4 NASA Ground System The means to capture and disseminate the science data for the mission is provided by the Mission Operations and Data Systems Directorate MO amp DSD in GSFC in NASA A combination of GSFC institutional and mission unique elements comprise the TRMM Ground Data System GDS The focal point for mission operations is the TRMM Mission Operations Center MOC From here the TRMM FOT conducts real time and off line activities required to support the mission Figure 3 4 1 provides a functional diagram of the TRMM Ground System Main elements of the NASA s ground system for the TRMM mission operations are e Mission Operation Center MOC e NASA Communications e
44. TRMM observatory is sun asynchronous and the satellite attitude is described by the following orbital elements see also Figure 2 3 1 The nominal values of these elements for TRMM observatory are approximately as follows as of orbit altitude 2 350 km a Semi Major Axis 6728 388 1 25 km b Eccentricity 0 00054 0 0001 c Inclination 35 0 1 deg d Argument of Perigee 90 2 0 deg e Orbit Period 91 538 0 026 min X i2 Y 55 gt f t ELS et d u pr E A 3 Y th L 4 Y N i N a X X X WY v 5 gt Y Y v E OOO KO A e AN LX AV AYN v v A AN 20 S LY SN Se B PK X AX X X X XX XX QUA NN A Y AA etl a pe 9 p CN X X A X 4 6 AN 05 X a 4 C X EX gt KS VAS A VA Ax AL A Xi x 7 X 2 X AV M j v i i 7 A rf amp Figure 2 3 1 Orbit 2 18 TRMM DATA USERS HANDBOOK 2 4 Mission Operation Phase of TRMM The operational life cycle of TRMM starts with the pre launch initial planning stage and then after orbital mission operation ends with ocean disposal of TRMM observatory The normal mission operation phase depends he
45. TRMM on Wakasa February 23 Gulf 2001 Start of the maneuver for raising of TRMM s orbit August 7 4 altitude August 24 Completion of the maneuver for of TRMM s orbit altitude November 9 GPM Symposium May 20 May 22 GPM International Workshop 2nd July 22 July 26 The International TRMM Science 150 2002 October 3 TRMM Tropical Cyclones Data Base was opened November 14 TRMM Commemorative International Symposium 5 anniversary of the TRMM satellite launch 2003 September 8 TRMM Tropical Cyclones prompt report was opened February 2 GPM Asian Workshop April 14 Processing of PR TMI VIRS and COMB data by 2004 P software version 6 was started The International TRMM Science Conference 2nd September 10 JAXA and NASA decide to extend the TRMM October 4 nw th 2005 mission until September 30 2009 November 7 November 9 GPM International Plan Workshop Sth Tt is expected that the TRMM mission life will be extended around few years although it depends on solar flux activity 62 TRMM DATA USERS HANDBOOK 6 1 On Orbit Initial Check out Result A communication line with TDRS was established after fairing cover was opened and the normal condition of TRMM satellite was confirmed And then TRMM was separated from the H II launch vehicle and Solar Array Paddle was deployed and three axis stabilized attitude was established by the automatic sequence After that the function
46. VIRS and TMI instruments activities Instrument activities are normally requested at least two weeks prior to the event week Activities that require changes to the nominal spacecraft orientation such as the Antenna Pattern Measurement will require four weeks advance notification to the FOT via the SOCC for coordination with other instrument and spacecraft activities and for generation of special planning products In addition the SOCC must provide command parameter inputs to the FOT no later than three days prior to the scheduled activity due to the load generation process A timeline report will be provided to the SOCC to allow for coordination of PR TMI and VIRS activities with those of CERES LIS 2 22 TRMM DATA USERSHANDBOOK and the spacecraft In the event of an instrument conflict the SOCC and FOT will attempt to resolve the issue If the conflict cannot be resolved the TRMM Joint Science Team and POD will come to an agreed upon resolution It should be noted that all required spacecraft maneuvers 180 yaw maneuver and Delta V maneuver will take precedence over an instrument activity request Given the following activity priority guidelines we believe that conflict resolution will not be necessary beyond the SOCC FOT interface The following list defines the priority of activities for the TRMM observatory 1 Any spacecraft anomaly 1 SafeHold Low Power etc 2 Instrument Safing 3 Recorder Playbacks
47. a Module 1 1 Initialize all sums 2 Ingest 2A12 and 2B31 overlap region The details depend upon TSDIS but the algorithm needs the orbit numbers for first and last orbit of the month 3 Derive adjustment ratios b Module 2 The second module consists of adding the TMI 2A12 and then applying the adjustment ratio 1 Sum the hydrometeors while counting the number of overpasses 2 Calculate monthly accumulations 3 Apply adjustments 4 Write output b Input Data of 3B31 Processing For 3B31 processing TMI 2A12 and 2B31 are input and the following reference data is necessary for processing of TMI data lt Supplied by TSDIS gt Land Ocean database with 4 km resolution c Output Data of 3B31 Processing The outputs of 3B31 processing are listed in below Surface Rain TMI mm sfcrainTMI Surface Convective Rain TMI mm convectRain Surface Rain Comb mm sfcrainCOMB Precipitation Water Comb g m rainWaterCOMB Surface Rain Overlap mm sfcrainTMlIoverlap Surface Convective Rain Overlap mm convectRainoverlap Surface Rain Overlap Comb mm sfcrainCOMBoverlap Ratio of Surface Rain surfAdjRatio Surface rain from 2A12 monthly accumulated in each 5 x 5 grid Convective surface rain from 2A12 monthly accumulated in each 5 x 5 grid Surface rain from 2B31 monthly accumulated in each 5 x 5 grid Monthly mean rain water at eac
48. also used later in subsystem 8 to aid in the production of monthly average cloud and radiation data The process for synoptic processing involves the following steps 4 53 Section4 OUTLINE OF THE TRMM PRODUCTS 1 Regionally and temporally sort and merge the gridded cloud and radiation data produced by subsystem 6 Regionally and temporally sort and merge the near synoptic geostationary data 3 Interpolate cloud properties from the CERES times of observation to the synoptic times Interpolate cloud information and angular model class convert the narrowband GOES radiance to broadband using regional correlations to CERES observations and then convert the broadband radiance to broadband TOA flux using the CERES broadband ADM s 5 Use the time interpolated cloud properties to calculate radiative flux profiles as in subsystem 5 using the synoptic TOA flux estimates as a constraint 6 Use the diurnal shape of the radiation fields derived from geostationary data but adjust this shape to match the CERES times of observations assumed gain error in geostationary data The system described above could also use the ISCCP geostationary cloud properties The disadvantage of this approach 1 that it incorporates cloud properties which are systematically different and less accurate than those from the cloud imagers flying with CERES The ISCCP cloud properties are limited by geostationary spatial resolution spectral channels and calibration
49. an institutional element of the MO amp DSD developed and operated under the Networks Division The NCC provides all Spaceflight Tracking and Data Network STDN scheduling configuration control performance monitoring and real time operations support This includes all network elements of the Space Network SN Ground Network GN and the Deep Space Network DSN 3 4 4 Hlight Dynamics Facility FDF The FDF is an institutional element of the MO amp DSD developed and operated under the Flight Dynamics Division FDD The FDF provides orbit determination onboard attitude control performance assessments and sensor calibrations orbit and attitude maneuver support TRMM tracking data processing for computation of orbit position TRMM Transponder center frequency measurements and planning scheduling product generation While these items may be considered off line or non real time activities the FOT ensures that selected attitude parameters from the real time telemetry stream are forwarded to the FDF The FDF facility is also equipped with a MOC remote display capability 3 4 5 Sensor Data Processing Facility SDPF The SDPF operates under the Information Processing Division IPD at GSFC The SDPF performs Level O telemetry processing on all data acquired and provides the capability for efficient and timely transfer of processed data to the user The SDPF receives real time and playback data packets and generates Level 0 and Quicklook data files
50. and PR measurements at the same location Since PR points at nadir and TMI points at a 49 angle off of nadir the co located measurements will occur around a minute apart The formats in this document for products with overlap 1A 11 1B 11 and 2A 12 follow the 4 74 TRMM DATA USERSHANDBOOK assumption that uniformity within one granule is preferable to uniformity for the same pixel across granules Therefore one ephemeris file and one UTCF are used in one granule In a similar vein the calibration is started at the beginning of the granule and reaches satisfactory values within 10scans The advantage of granule uniformity is that there are no discontinuities within a granule and processing has only to input one granule in order to output one granule The disadvantage is that a pixel in one granule may have a different value location and time from the same pixel in another granule When such a difference occurs the pixel is in an overlap region in one of the granules According to the TRMM requirements the location and time differences will be less than 1 km and 1 ms respectively In Level 1A extra usually one ACS and instrument housekeeping packets are added to ensure that each science packet has an ACS and instrument housekeeping packet before and after the science packet 4 2 3 6 Scans Granule The average number of scans in a granule is shown in the structure diagrams and array dimensions as nscan For VIRS and P
51. and special test interfaces The ES is comprised of two Power Switching and Distribution Units PSDUs power distribution modules located in the GSACE and the electrical and optical harnessing Figure 2 1 4 provides a block diagram of the ES POWER SUBSYSTEM UNSWITCHED POWER g UNSWITCHED POWER SWITCHED POWER SWITCHED POWER SWITCHED HIGH POWER Other functions NOT associated PYROTECHNIC CONTROL with the Electrical Subsystem 1773 BUS UNSWITCHED POWER SWITCHED POWER DISCRETE COMMANDS SERIAL COMMANDS IPSDU CLOCK DISTRIBUTION DISCRETE TELEMETRY SERIAL TELEMETRY SPECIAL MODE NOTIFICATION POWER SUBSYSTEM Figure 2 1 4 Electrical Subsystem Block Diagram 2 1 4 Power Subsystem PWR The PWR is a Peak Power Tracking system consisting of two Super Nickel Cadmium Batteries four solar panels mounted as two wings of two solar panels each and the Power System Electronics PSE The PWR provides 1100 watts of power and is connected directly to the Essential and Non Essential Buses The PSE consists of the Power System Interface Box PSIB Standard Power Regulator Unit SPRU and the Power Bus Interface Unit PBIU The PSIB is a microprocessor based unit that provides the interface between the PWR and the FDS The PSIB also performs PWR monitoring Section2 OUTLINE OF THE TRMM SATELLITE and control functions such as individual Battery Cell voltage monitoring and Amp Hour Integratio
52. be performed during the instrument checkout period To perform this calibration the CERES instrument will require that the TRMM spacecraft attitude be modified from nadir pointing to an inertially fixed attitude The anomaly that an over voltage was loaded for the CERES instrument occurred around August 1998 nine months after launch CERES operation was completely terminated in May 2001 e 000000 200000 00 0 oo Spacecraft 0 Motion x 00 forward 026 Unit vector in direction of orbit momentum Beta angle 35 55 45 35 Elevation Angle 0 0 Timeout 0 command d Normat Scan 13 35 45 55 55 45 35 25 15 5 0 355 345 335 325 315 305 Azimuth Angle Figure 2 5 5 CERES Scan Profile 2 30 TRMM DATA USERSHANDBOOK 2 5 2 5 LIS The operation of the LIS instrument is very basic During normal science operations the LIS instrument will continuously operate through day and night periods in the science mode The instrument will acquire successive observations every two ms If a lightning event is identified during this two ms sample period then the location intensity and time of each event is reported Once powered the LIS instrument will be configured for a normal science data collection mode The FOT during normal operations need only to verify this configuration In addition continuous automated
53. enne nnne 3 16 3 4 6 Science Data and Information System TSDIS cessere 3 19 3 4 Langley Research Center LARC sic ui eH eie e de eiie ied Eden 3 20 3 4 8 Marshall Space Flight Center eene entren enne 3 20 3 40 Space Network SN 4 Ace notae eer ert n e ee EC e ep 3 20 3 4 10 Wallops Fight Facility WEE edere tee ied ah P aede sind 3 20 OUTLINE OF THE TRMM 4 1 4 1 Data Productz ii ie ttti ree p rt eet er eee dee ped eee 4 2 411 Ren 4 4 ALIA Product Defiitionos dene e en 4 5 4 1 1 2 Outline of Processing Algorithm eese eene netten enne 4 5 4 1 1 3 Data Usage iis te i EA RENI SERE SERE NS SERE EE RIEN PI H TREE E RS 4 34 4qdq2 re a EO EE 4 35 42 1 Product Definitlonussz e BE BERE ER B e ees 4 35 412 2 Processing Algorithm e ree 4 35 4 1 3 ge 4 41 41 3 1 Product Definitlonz v ee o e n E B D EY E e ARV EET REO SERES 4 41 4 13 2 Processing Algorithm ia adu ute A a e E eris 4 41 BAD Aq COMB aite eee eet it eser tete cie ep eite e e tire ee idee edle alae dene 4 42 BAAD Product Definition set tene e ee rne e He n EE 4 42 4 1 4 2 Processing Algorithm ennnen nnn esent eene entente rennen tenen nns 4 42 Bled CERES dise chen E
54. groups level 2 flashes level 2 areas level 2 vector data level 2 browse data level 3 orbit statistics level 3 flash density maps level 4 and metadata Before we can discuss the details of the various components we must define each of the underlying data storage classes that drive the algorithm These data storage classes are backgrounds events groups flashes areas and orbits a Background A background image is a snap shot of the background estimate created by the LIS Real Time Event Processor RTEP The background data consists of 12 bit raw count amplitudes at each of the 128x128 pixel locations and the time at which the background image was taken The background is identified as LISO2 The background is transmitted in the data stream along with event data to maintain the average transmission rate When the transmission of one background is begun the next background image is captured New images are sent to the ground as frequently as the event load and transmission rate allow b Event An event is defined as the occurrence of a single pixel exceeding the background threshold during a single frame In other words each pixel output from the RTEP produces a separate 4 58 TRMM DATA USERSHANDBOOK event The raw LIS instrument data consists of time x and y pixel locations and amplitude of the event An event is the basic unit of data from the LIS An event is identified as 11503 Although an event c
55. in space by no more than 16 5 km approximately 3 pixels The spatial rule can be easily adjusted in the LIS algorithm processing software if necessary after analysis of OTD and or LIS data An area may include many flashes or contain as few as one event i e one flash consisting of one group which in turn consists of one event There is no interflash or absolute time limit rule being imposed in the area definition since as noted previously the LIS viewing time is much shorter than storm life cycle Although there is no explicit limit to the temporal duration of an area 1 as long as there are events groups flashes in the region all will be assigned to the area the LIS instrument will only view any ground location within its FOV for a maximum of 80 seconds Therefore area duration will generally not exceed 80 seconds except possibly for very extensive and very active mesoscale storm complexes An area 1 identified as 11506 The area definition serves as a proxy for a thunderstorm however due to the nature of the algorithm and possible spatial and temporal distribution of the data several storms may be combined into one area It is also possible for a single thunderstorm to be divided into more than one area More sophisticated algorithms with input from external ground airborne and space based observing systems will be needed to more precisely determine thunderstorms in the LIS data f Orbit The data granule for TRMM ha
56. integration at 100ms Time 350 ms The next integration time with data is shown in Figure 4 1 15 The time is 350 ms after the time of the first events but only 250 ms after the time of the last events At this time there are four 7 8 9 10 more events Events 7 and 8 are adjacent to each other and are assigned to a new group c Events 9 and 10 are not adjacent to events 7 and 8 but are adjacent to each other They are assigned to another new group d Since group c is within 330 ms of the last group of flash A 250 ms and is also within 5 5 km of the parts of flash A group c is assigned to flash A and area Although group d also occurred within 330 ms of the last group of flash A it is greater than 5 5 km away from any part of flash A so it is assigned to a new flash B The parts of flash B 1 group d are greater than 16 5 km away from any part of area a so flash B 1 also assigned a new area Time 35 ms Event Group Flash Ares 1 2 Be b ui 4 n P ue o E p BH ge ui 10 Figure 4 1 15 Time integration at 350115 Section4 OUTLINE OF THE TRMM PRODUCTS d Time 400 ms Figure 4 1 16 shows the next integration time with data The time is 400 ms after the first events and 50 ms after the latest events Two more events occur 11 12 at this time These two events are at the same time but they are not adjacent to each other They are a
57. is estimated from the received power value of the very small amount of scattering echo from raindrops Therefore an error in the received power directly leads to an estimation error of the rainfall rate and hence calibration with sufficient precision is necessary Accordingly an active radar calibrator is positioned outside when TRMM orbit and the ARC position overlap each other during absence of rain so as to measure aged deterioration of the precipitation radar and so on This facility comprises an antenna for radar signal reception frequency converter for received signals electronic instruments for amplification and others and an antenna for signal transmission The appearance diagram of ARC is shown in Figure 3 2 5 2 Main Functions The main functions of the precipitation radar calibrator are as follows a Reception function b Transmission function c Reflection reception transmission function d Transfer of data using floppy disk as a medium e Calibration value input function for data conversion 3 Execution of Processing It is normally stored in a storehouse but is moved to the setup position from the storehouse when required for usage For that reason ARC is made portable The operation commences when ARC is fixed to the setup position and the face with the antenna is adjusted to be horizontal TRMM DATA USERSHANDBOOK variable angle variable angle Dyna Book GT475 H Toshi
58. is the area symmetrical to both right and left of nadir The diagram shows only one side 327 km cs Ground surface Satellite altitude at 350km For mirror image Figure 2 6 10 Data Sampling Area during the Observation Mode Orbit altitude 350 km TRMM Satellite NB The area sampled is the area Reference point of the range symmetrical to both right and left of nadir The diagram shows only 327 km one side 327 km 23 km Ground surface 330 Satellite altitude at 350 km 400 238 400 Figure 2 6 11 Data Sampling during External Calibration Mode Orbit altitude 350 km 2 52 TRMM DATA USERSHANDBOOK 2 6 6 3 Geometric Model The geometric model of the precipitation radar can be expressed using four coordinates systems such as the Radar Electric coordinates system the Radar Mechanical coordinates system the Alignment coordinates system and the Satellite Mechanical coordinates system The relationship between these coordinates systems is shown in Figure 2 6 12 The Radar Mechanical coordinates system is the reference coordinates system of PR the scanning will be done around the x axis in this coordinates system The Radar Electric coordinates system is the system which it rotated the Radar Mechanical coordinates system around the y axis by 1 approx 4 and it is the middle value of the beam positioning directions when respectively frequency 1 f2 The Alignment coord
59. limit checking will be performed during all real time contacts with the spacecraft Instrument commanding will be somewhat frequent during L amp EO until instrument checkout has been completed Operations will almost exclusively consist of changing the threshold values in the RTEP Real Time Event Processor Once data is analyzed and the best threshold values are determined commanding will be minimal LIS does not have any requirements for special configurations during spacecraft activities such as the Yaw maneuvers Delta V maneuvers or the CERES Deep Space Calibration Section2 OUTLINE OF THE TRMM SATELLITE 2 6 PR Detailed Explanation The precipitation radar PR on TRMM is the first precipitation observation radar on board a satellite in the world and was developed by NASDA with the cooperation of CRL PR is a radar system that measures the precipitation echo intensity using a 13 8 GHz band within a range of approximate width 215 km and an approximate altitude 15 km at a sub satellite point Major objectives of the precipitation radar are 1 To observe the three dimensional structure and especially the vertical distribution of rainfall 2 To carry out quantitative observation of precipitation over the ocean and land 3 To improve the precipitation observation precision of TRMM microwave imager TMI by providing data related to rainfall structure 2 6 1 Elements and Appearance Major elements appearance and function
60. linear interpolation The sum of the precipitation water content calculated from Ze at each range bin The summation is from the rain top to the actual surface Quality flag for each angle bin data Rain rate for 2 D array of each angle bin and range bin 49 x 80 elements Average of rain rate between altitude 2 and 4 km If the lowest bin processed is higher than 2 km the average is taken between the lowest altitude and 4 km If the lowest bin processed is higher than 4 km the average is not calculated In this case 0 is stored Rain flag for each angle bin Exact copy of rainType in 2A23 Range bin number of bright band height storm top height and so on Reliability parameter at each range bin The angle between the local zenith on the Earth ellipsoid and the beam center line Exact copy of sigmaZero from 2 21 Integral of alpha Zm beta from rain top to the lowest surface clutter free height Mean of zeta over 3 x 3 beam IFOV At scan edge mean is calculated in 6 beams Standard deviation of zeta over 3 x 3 beam IFOV At scan edge mean is calculated in 6 beams Maximum value of measured Z factor Zm in the beam IFOV 66 99 Rain rate parameter a of relationship equation between rain rate R and Z factor Ze a is given at five nodal points and a values between the nodes are calculated by linear interpolation Rain rate par
61. mm h R hat is the instantaneous rain rate at the radar range gates RMS rHat uncertainty in R hat is also recorded as Sigma R hat sigmaRHat RR Surf The RR Surf is the surface rain rate RMS uncertainty in RR Surf is rrSurf also recorded as Sigma RR Surf sigmaRRsurf latentHeatHH LatentHeatHH is the hydrometeor heating in K hr calculated from latentHeatHH the vertical fluxes of the different hydrometeor species and using average archival temperature pressure humidity soundings which depend on longitude and latitude only d Relationship with Other Algorithms The output of 2B31 is used for 3B31 2 3B31 Processing a Processing Description The objective of the 3B31 algorithm is to uses the high quality rainfall retrievals done for the PR s narrow swath 220 km in combined 2B31 data to calibrate the TMI s wide swath 760 km rainfall retrievals generated in TMI 2A12 data It calculates monthly accumulated rainfall at each 5 x 5 grid for near surface and 14 vertical layers For each 5 x 5 grid an adjustment ratio will be calculated from the swath overlap region which will then be applied to the 2A12 product in order to produce monthly means Detailed coregistration is not necessary since the overlap in the swaths corresponds to pixel number s 79 129 of the TMI The algorithm is divided into two modules The first module is used to derive the adjustment ratios Section4 OUTLINE OF THE TRMM PRODUCTS
62. of SW and LW flux are time averaged using a data interpolation method similar to that employed by the ERBE Data Management System The averaging process accounts for the solar zenith angle dependence of albedo during daylight hours as well as the systematic diurnal cycles of LW radiation over land surfaces The averaging algorithms produce daily monthly hourly and monthly means of TOA and surface SW and LW flux on regional zonal and global spatial scales Separate calculations are performed for clear sky and total sky fluxes 4 51 Section4 OUTLINE OF THE TRMM PRODUCTS 4 Subsystem 4 Overview of Cloud Retrieval and Radiative Flux Inversion One of the major advances of the CERES radiation budget analysis over ERBE is the ability to use high spectral and spatial resolution cloud imager data to determine cloud and surface properties within the relatively large CERES field of view This subsystem matches imager derived cloud properties with each CERES FOV and then uses either ERBE ADM s Releases 1 2 and 3 or improved CERES ADM s Release 4 to derive TOA flux estimates for each CERES FOV Until new CERES ADM s are available three years after launch the primary advance over the ERBE flux method will be to greatly increase the accuracy of the clear sky fluxes The limitations of ERBE clear sky determination cause the largest uncertainty in estimates of cloud radiative forcing In Release 4 using new ADM s both rms and b
63. of TRMM bus instruments and mission instruments were checked The PR was first powered in orbit on December 1 1997 JST and it was confirmed that the radar was operating normally After the satellite attained the nominal altitude of 350 km the PR was set to the observation mode at 5 45 pm Japanese standard time on December 8 to start the initial check out The PR initial check out including the performance verification of PR by the ARC was completed successfully in middle January 1998 PR acquired rainfall data on December 9 1997 when TRMM passed over Okinawa and over Cyclone PAM at the northeast of New Zealand These rainfall data were released as the first images of PR on December 17 Figure 6 1 1 Figure 6 1 1 1 2 gives a detailed structure of rain around the cyclone widely and clearly and you can see there is a rainfall at higher altitude near the eyewall cloud PR has the range resolution of 250 m and the horizontal resolution of 4 km and this image shows their performances PR is the radar system onboard a satellite Therefore PR has an advantage that there is few difference for ranges separately from ground base radars In addition we could observe only rainfall of close to land area by using radars on ground until now However TRMM can observe rainfall over sea areas Moreover usual meteorological satellites can observe only around top of clouds on the other hand PR can measure 3 D structure of rainfall within c
64. on off using command signal At the same time it starts up the PLO unit 8 Outputs the on off status of FCIF as a telemetry signal 9 Possesses a temperature sensor and outputs it as a telemetry signal 1 of command signals and control signals are transmitted from the system control data processing section Also all telemetry signals are output to the system control data processing section NB 2 When FCIF A system B system is turned off there is no gate signal to the A system B system of TDA RDA c Operating state Operating states of FCIF are as follows Also transition between operating states are shown in Figure 2 6 7 1 State 1 FCIF is turned off 2 State 2 FCIF is turned on and there is no pulse transmission 3 State 3 FCIF is turned on and there is pulse transmission 4 State 4 Calibration is carried out by the RF signal reflection loop 2 48 TRMM DATA USERSHANDBOOK Normal modes transition during observatior Control Signa Control signal Command Command Figure 2 6 7 Transition of FCIF States 3 PLO Unit a Structure PLO unit is one of the composition instruments of the signal processing subsystem of the precipitation radar One PLO unit makes up the internal redundant system It generates local signals to whichever one of the FCIF A system B system that has the power supplied to it The PLO operation when FCIF A system is turned on is shown in Figure 2 6 8 Local
65. only over the equator these areas correspond to the Inter Tropical Convergence Zone ITCZ Although lightning in the Northern Hemisphere where it was winter was not so active There were some lightning flashes near Japan and the east coast of North America where winter lightning is sometimes generated The winter lightning is single lightning because of its weak activity and short duration LIS observed this kind of lightning 6 16 TRMM DATA USERS HANDBOOK Fig 2 Fatal Number of Lightning Flashes January 15588 Figure 6 4 6 Total Number of Lightning Flashes 6 5 TRMM Follow On 1 Expectation to the TRMM Follow On Mission TRMM was launched successfully in November 1997 and it keeps sending data on the three dimensional construction of the rainfall after that and has been bringing a big scientific result However there is a limitation to grasp the rainfall distribution and fluctuation conditions of the world Though a rainfall changes even for a short period of time there is a long fluctuation too For example when the amount of precipitation of the Indian Monsoon for about 100 years is seen it has known that there are a few rainfall at the time of the El Nino in the Indian Monsoon area The El Nino appears several times per 10 years in this period The mission life of TRMM is limited and it has the possibility that the fluctuation of the cycle of the Nino and La Nina can t be observed only with TRMM Actually the
66. procedure is repeated for each of the six possible freezing heights determined earlier The algorithm then opens the cloud model profile database Each pixel is then examined sequentially if dataflag clearsky and cloud only are not set then the cloud profiles are examined otherwise the pixel is skipped For each profile the rms deviation between it and the measurements are calculated A new profile is constructed based upon the combination of all profiles in the database weighted by the rms value calculated above This step is repeated six times for various freezing heights If a pixel does not meet the minimum rms set by the algorithm it is flagged as unretrieved The algorithm continues by examining all pixels labeled as unretrieved Procedures are then employed to either interpolate the pixel value based upon neighbors or to set the pixel to missing Neighboring pixels as well as minimum rms are used to make this decision c Input Data of 2A12 Processing For 2A12 processing 1 11 is input and the following reference data are used lt Supplied by TSDIS gt Land Ocean database with 4 km resolution Topographic database with 4 km horizontal 200 vert res lt Supplied within algorithm gt Climatology of Sea Surface Temp 1 file 300 Kbytes Database of cloud only profiles 6 files 15 Kbytes Database of cloud model profiles 6 files 30 Mbytes the files listed above are accessed every time the alg
67. products 0 Unprocessed instrument data time ordered quality checked no redundancy BEN data and georeferencing data attached to Level 0 and processed to sensor dependent 2 physical units e g radar reflectivity brightness temperature Meteorological parameters e g rainfall rate derived from Level 1 data using various algorithms which will be produced as a 2 or 3 dimensional rain map along the TRMM swath Results of mapping the meteorological parameters Level 2 on a uniform space and time grid The TRMM Level 0 Data have the following characteristics a Consists of data units received during multiple acquisition sessions Selected by a single SCID and single or multiple APID VCID or combination there of and sorted by time and sequence count Arranged in time forward order Merged real time and playback raw telemetry Optionally do not contain some of the data units forwarded as Quicklook data Optionally duplicate data units are deleted Optionally include quality and accounting information e g data unit errors identified missing data unit gaps etc h Produced according to a prearranged schedule and by special request These are typically defined in one of the following ways h 1 A fixed number of data units per data set e g generate a data set every X number of data units h 2 A fixed ground time period containing all data units received since the last data set generat
68. rain Same as the above but for stratiform rain The following parameters are given for only 5 x 5 grid Total Angle Pixel ttlAnglePix1 Rain Angle Pixel rainAnglePix1 Number of observations for each 5 x 5 grid at incidence angles approximately of 0 5 10 and 15 Number of rain observations for each 5 x 5 grid at incidence angles approximately of 0 5 10 and 15 4 25 Section4 OUTLINE OF THE TRMM PRODUCTS Rain Rate Correlation Coefficients Pixel rainCCoefPix Stratiform Rain Rate Correlation Coefficients Pixel stratRainCCoefPix Convective Rain Rate Correlation Coefficients Pixel convRainCCoefPix SRT PIA Pixel piaSrtPix SRT PIA subset Pixel piaSrtssPix HB PIA Pixel piaHbPix HB PIA subset Pixel piaHbss Pix 0 PIA Pixel pia0Pix 0 Order PIA subset Pixel pia0ssPix 2A25 PIA Pixel pia2A25Pix 2A25 PIA subset Pixel pia2A25ssPix BB Nadir direction Pixel bbNadirPix1 Number for correlation coefficients of rain at the three heights Same as the above but for stratiform rain Same as the above but for convective rain Number of PIA that are calculated by using SRT Surface Reference Technique at five incidence angles 0 5 10 15 and mean of 49 angle bins Same as the above but for subset Subset is when w equals or 2 for Reliability Flag in 2A21 and 8th bit equals 1 for method in 2 25 Num
69. rain Rain Pixel Total Pixel Pr stratiform rain Stratiform Rain Pixel Total Pixel Pr convective rain Convective Rain Pixel Total Pixel Pr bright band Bright Band Pixel Total Pixel Pr stratiform rain rain Stratiform Rain Pixel Rain Pixel Pr convective rain rain Convective Rain Pixel Rain Pixel Pr bright band rain Bright Band Pixel Rain Pixel path average Moreover the difference among quantities of the following kind can be calculated Pr stratiform rain rain Stratiform Rain Pixel at an layer Rain Pixel at same layer Pr stratiform rain rain Stratiform Rain Pixel at an layer Rain Pixel path average Pr stratiform rain Stratiform Rain Pixel path average Rain Pixel path average Pr corresponds to what is the most common definition of the probability of stratiform rain given that rain is present what is the probability that it is stratiform Pr is the probability that given rain is present at a particular height level that the rain is stratiform Pr is the probability given that rain is present somewhere along the beam that rain is present at particular height and that the rain is stratiform b Means and Mean Square lt Rain Rate Parameters gt mm h The following parameters are output for both 5 x 5 and 0 5 x 0 5 grid Rain Rate Mean and standard deviation of rain rate each layer path 1 average condition
70. rates over the oceans but less reliable data over land where non homogeneous surface emissions make interpretation difficult The TMI instrument is similar to the SSM I instrument currently in orbit on the Defense Meteorological Satellite Program spacecraft The TMI data combined with the data from the PR and VIRS also utilized for deriving precipitation profiles The TMI instrument has a single operational mode and no commandable redundancy Accordingly command procedures are minimal and focus on power and heater control TMI essentially has two modes OFF and ON Two external calibrators on the stationary shaft are used to perform calibrations during each instrument rotation scan The instrument spins at a rate of 31 6 RPM Each scan begins with 130 of scene data followed by a cold reference measurement and then a hot load reference measurement These reference measurements along with the known temperatures of the calibration loads serve to calibrate the scan 2 2 2 2 System Parameters Figure 2 2 2 provides a graphical description of the TMI instrument diagram Table 2 2 4 provides the TMI system parameters Table 2 2 5 provides the observation characteristics and Table 2 2 6 provides the observation performance Figure 2 2 2 TMI Instrument Diagram TRMM DATA USERSHANDBOOK Table 2 2 4 TMI System Parameters 10 65 19 35 21 3 37 and 85 5 GHz Vertical Horizontal 21 3 GHz Channel Vertical only 6 50km 760 k
71. set to END in accordance with the calendar month specified TSDIS scheduler and the end of orbit processing has been completed 3B42 software computes the calendar monthly averages of the clipped VIRS clipped TMI and unclipped TMI precipitation data And then 3B42 software reads the product 3B31 which is in HDF extracts 4 45 Section4 OUTLINE OF THE TRMM PRODUCTS the TMI TCI TRMM Combined Instrument calibration parameters interpolates them to the 0 25 resolution and multiplies them by the monthly average clipped TMI data to obtain the monthly average clipped TCI precipitation and observation count data The monthly average clipped VIRS and TCI precipitation and observation count data are then used to compute the calendar month IR calibration parameters b Adjustment of Merged IR Precipitation amp Estimation of RMS Error The merged IR data are supplied at the 0 25 spatial resolution and the three hours temporal resolution in 5 day pentad spans 3B42 software extracts the specified day of merged IR data from the flat binary pentad file The day of merged IR data is then calibrated to the bias of the VIRS data A calendar month of multiplicative IR calibration parameters are then read and used to adjust the day of merged IR precipitation rate data After the precipitation rate data have been adjusted a corresponding RMS precipitation error estimate is calculated b Input Data of 3B42 Processing For 3B42 pro
72. temperature data sst hou data is used for calculation of freezing level 4 18 TRMM DATA USERSHANDBOOK height c Output Data of 2A23 Processing The outputs of 2A23 processing are listed in below Rain Flag rainFlag Rain Type rainType Shallow Rain ShallowRain Processing Status Status Peak Bin of Bright Band binBBPeak Height of Bright Band m HBB Intensity of Bright Band dBZ BBintensity Identical to the minimum echo flag of 1C21 Rain type is classified as follows 100 170 Stratiform Rain with bright band and comparatively weak Z factor or rain having similar characteristics 200 291 Convective Rain Rain with no bright band and with strong Z or with Z which stands out against background Z of rain area 300 313 Other Rain cloud and or noise 88 No Rain 99 Data missing Shallow rain flag 10 May be shallow isolated 11 Shallow isolated with confidence 20 May be shallow non isolated 21 Shallow non isolated with confidence 88 No rain 99 Data missing Status flag for processing of 2A23 0 9 Good 10 49 may be good 50 99 Result not so confident warning 100 Bad untrustworthy because of possible data corruption 88 No rain 99 Data missing Range bin number that corresponds to the bright band gt 0 Range bin number 111 No bright band 8888 No rain 9999 Data missing Height of bright ban
73. the CERES data flow diagram shown in Figure 4 1 10 Circles in the diagram represent algorithm processes which are formally called subsystems Subsystems are a logical collection of algorithms which together convert input data products into output data products Boxes represent archival data products Boxes with arrows entering a circle are input data sources for the subsystem while boxes with arrows exiting the circles are output data products The list of CERES data products is shown in Table 4 1 5 Data output from the subsystems falls into three major types of archival products a ERBE like Products which are as identical as possible to those produced by These products are used for climate monitoring and climate change studies when comparing directly to ERBE data sources process circles and ATBD subsystems 1 2 and 3 ERBE Earth Radiation Budget Satellite Scanning Radiometer onboard the ERBS NOAA 9 and NOAA 10 SURFACE Products which use cloud imager data for scene classification and new CERES derived angular models to provide TOA fluxes with improved accuracy over those provided by the ERBE like products Second direct relationships between surface fluxes and TOA fluxes are used where possible to construct SRB estimates which are as independent as possible of radiative transfer model assumptions and which can be tuned directly to surface radiation measurements These products are used for studies of land and oce
74. the mission barring any unforeseen anomalous conditions 2 2 5 2 System Parameters Figure 2 2 5 provides a graphical description of the LIS instrument diagram Table 2 2 10 provides system parameters Figure 2 2 5 LIS Instrument Diagram Table 2 2 10 LIS System Parameters Observation Band 0 777655 um Horizontal Resolution 4 km nadir Swath Width 600 km Ave 6 kbps 18 kg For pre orbit boost See Section 2 7 5 about parameters of post orbit boost August 2001 2 17 Section2 OUTLINE OF THE TRMM SATELLITE 2 3 Outline of the Orbit TRMM was launched from the Tanegashima Space Center by the H II rocket No 6 of NASDA along with ETS VII on November 28 1997 JST The H II rocket injected TRMM into an orbit of 380 km with the orbital inclination at 35 degrees In orbit TRMM rotates around the earth approximately every 90 minutes and 16 orbits a day subsystems and equipments except for CERES completed their operation checkouts 26 days after launch At this point Dec 29 the satellite entered a normal operation stage and science observation started During the initial operation a number of descent trajectory controls have been carried out and then the orbit of TRMM was transferred to the mission altitude approx 350 km and orbit period of 91 5 minutes A 90 degree yaw maneuver was carried out to support the calibration of the precipitation radar and the altitude control sensor The period of
75. the process outlined for synoptic products in subsystem 7 We include this method to minimize problems during the initial flight with TRMM when we have only one spacecraft with two samples per day As the number of satellites increases to 3 the geostationary data will have little impact on the results Because one of the major rationales for the Surface Data Products is to keep surface flux estimates as closely tied to the CERES direct observations as possible this subsystem will not calculate in atmosphere fluxes and will derive its estimates of surface fluxes by the same methods discussed in subsystem 4 6 11 Subsystem 11 Grid Geostationary Narrowband Radiances CERES will use 3 hourly geostationary radiance data to assist diurnal modeling of TOA fluxes and to minimize temporal interpolation errors in CERES monthly mean TOA flux products This subsystem is essentially the same process as in subsystem 6 The major difference is that the process is performed on geostationary radiances instead of CERES TOA fluxes The current input data are one month of 3 hourly ISCCP geostationary GEO data which contain visible VIS and infrared IR narrowband radiances from different satellites At the present time GEO data are available for four satellites METEOSAT GOES East GOES West and GMS The spatial resolution of the GEO data set is approximately 10 km These data are gridded and 4 55 Section4 OUTLINE OF THE TRMM PRODUCTS spatial
76. to grasp rainfall distribution with the TRMM However at present the purpose of PR data usage has been changed variously For example PR data is used to improve the accuracy of rainfall estimation of the other sensors boarded on TRMM and also used for the estimation of the latent heat emission professional file Like this the PR data which grasps the three dimensional construction of the precipitation system is utilized for the accuracy improvement of the TMI and VIRS data within the PR observation width of 215 km of the PR Furthermore observation accuracy improves in the TMI and VIRS observation width of more than 760 km TRMM data is associated to the rainfall observation data of the other satellites such as SSM I NOAA GMS and so on and this method makes the climate value of the total rainfall distribution more accurately This concept will be realized by a constellation consisting of a core satellite of the TRMM type and eight small satellites with a microwave radiometer in GPM 6 18 TRMM DATA USERS HANDBOOK The backgrounds and the characteristics of TRMM follow on are shown as follows Three dimensional rainfall profile can be grasped globally by the observation from radar onboard satellite Three dimensional rainfall profile is very critical information for understanding vertical distribution of atmospheric heat due to the precipitation activities Three dimensional rainfall profile is very critical information for graspi
77. vector in Geocentric Inertial solarCal Coordinates and the Sun Earth distance Calibration Counts calCounts Temperature Counts tempCounts Local Direction deg localDirection Raw calibration counts which includes the data of black body space view and solar diffuser Temperatures of the black body the radiant cooler temperatures the mirror temperature and the electronics module temperature Angles to the satellite and sun from the IFOV pixel position on the earth Section4 OUTLINE OF THE TRMM PRODUCTS Channels Scene data for the five channels measured in multiplied by a scale channels factor c Relationship with Other Algorithms The output of 1B01 is used for 3B42 4 1 4 COMB COMB products are combined PR and TMI data products COMB data products and their algorithm is explained hereafter 4 1 41 Product Definition COMB data products are shown in Table 4 1 4 Table 4 1 4 COMB Products Level Description COMB Rain Profile consists of the correlation corrected mass weighted mean drop diameter coefficient of rain attenuation correction rain rate and PIA This product is processed from PR data and TMI 10 GHz channel data Standard deviation of each parameter are also calculated COMB Monthly Rainfall uses the high quality retrievals done for the narrow swath in combined 2B31 data to calibrate the wide swath retrievals generated in TMI 2A12 data It calculates monthly
78. 0 and the transmitter pulse width s The system noise consists of external noise and PR internal noise and is recorded as the total equivalent noise power at the PR antenna output System Noise is recorded in each angle bin and if data is missing the dummy value 32734 is recorded 4 10 TRMM DATA USERSHANDBOOK System Noise Warning Flag sysNoiseWarnFlag Minimum Echo Flag minEchoFlag First Echo Height binStormHeight Satellite Local Zenith Angle deg scLocalZenith Spacecraft Range m scRange Land Ocean Flag landOceanFlag Topographic Height m surfWarnFlag Range Bin Number of Ellipsoid binEllipsoid Range Bin Number of Clutter free Bottom binClutterFreeBottom Range Bin Number of Mean DID binDIDHmean Range Bin Number of Top of DID binDIDHtop Range Bin Number of Bottom of DID binDIDHbottom Bin start of oversample osBinStart Bin Number of Surface Peak binSurfPeak If the system noise level exceeds the noise level limit the flag is set to 1 This will occur when 1 a radio interference is received 2 system noise increases anomalously or 3 noise level exceeds the limit due to the statistical variation of the noise In cases 1 and 2 data should be used carefully In case 3 this flag may be neglected Five values are used in the Minimum Echo Flag for each angle bin see the above f The First Echo Height storm height is repres
79. 000 3 1 Section3 OUTLINE OF THE GROUND SYSTEMS Within 48 Hours Aft Earth Observation Center Observation Senser Data ii eee Processing Facility CERES Level 0 LIS Level 0 Data Data Data Science Data and TMI VIRS COMB Data Information Sysstem 10 E 7501 5 Products EOC i f Earth Observing System Data and Information System TRMM Data Archival Science Team Level 1 2 3 Data Leva 1 2 Data Figure 3 1 1 TRMM Total Ground System 3 2 TRMM Precipitation Radar Data Processing System The TRMM precipitation radar data processing system is a ground processing system set up at JAXA EOC and has processing verification and operations functions The outline of the TRMM precipitation radar data processing system is explained below Explanation of each piece of equipment in this system is given in Sections 3 2 1 to 3 2 4 1 Overall Structure The relationship between the TRMM precipitation radar data processing system and the foreign organizations is shown in Figure 3 2 1 and the overall structure diagram of the TRMM precipitation radar data processing system is shown in Figure 3 2 2 The TRMM precipitation radar data processing system is made up of four facilities comprising the processing facility the verification facili
80. 00m 4 65 Primary Data Structures enne 4 68 The Three Levels of Interaction with the HDF File Format eere 4 68 Generic Swath uie eret terree hr REPRE ER V Fr E Ea a aana 4 70 Generic Planetary Grid Str cture 3 onere ioter he ie rede t ote d cs 4 71 Example Product Str ctute nente tre dide eee edere qiiid qe ide Yen 4 73 Granule Structure Time Increases Toward the Right eese 4 74 Data Format Structure Tor adr oe eee e ts 4 80 Data Format Structure for 2 21 nenne 4 81 Data Format Structure for 2A23 4 82 Data Format Structure for 2 25 teen tnse teet E netten 4 82 Data Format Structure for 3A25 sess ener nnnm ener 4 84 Data Format Structure for 26 4 84 Data Format Structure for 1 11 4 85 Data Format Structure for 2 12 nnne tenent nnne nnne 4 86 Data Format Structure for 3A11 tnn tette 4 87 Data Format Structure for 1 01 4 88 Data Format Structure Tor 2B31 e e E e RA I RR 4 89 Data Format Structure for 3B341 dde dee weeds eth been 4 90 Data Format Structure for 3B42 4 91
81. 2 Zm Convective Rain Rate convZmMeanl convZmDev1 convZmMean2 Corrected rain attenuation Z Zi ztMeanl ztDev1 ztMean2 Same as the above but for stratiform rain Same as the above but for convective rain Mean and standard deviation of correct radar reflectivity factor each layer path average conditioned on rain 4 28 TRMM DATA USERSHANDBOOK Z4 Stratiform Rain Rate stratZtMeanl stratZtDevl stratZtMean2 7 Convective Rain Rate convZtMeanl convZtDevl convZtMean2 Maximum Z in bright band Zimax bbZmaxMeanl bbZmaxDevl bbZmaxMean2 Same as the above but for stratiform rain Same as the above but for convective rain Mean and standard deviation of maximum Z in bright band conditioned on presence of bright band lt Path Integrated Attenuation PIA gt dB km These parameters are output for only 5 x 5 grid SRT PIA piaSrtMean Dev SRT PIA subset piaSrtssMean Dev HB PIA piaHbMean Dev HB PIA subset piaHbssMean Dev 0 Order PIA pia0Mean Dev 0 Order PIA subset pia0ssMean Dev 2 25 PIA pia2A25Mean Dev 2A25 PIA subset pia2A25ssMean Dev Mean and standard deviation of PIA which is calculated by using SRT Surface Reference Technique at five incidence angles 0 5 10 15 and mean of 49 angle bins Same as the above but for subset Mean and standard deviation of PIA which is calculated by using H
82. 5 and 3A26 6 2A25 Processing a Processing Description 2A25 processing is to calculate Z factor correcting rain attenuation Ze for each beam position by using radar equation For this calculation Input data of this calculation is Z factor including rain attenuation Zm scattering cross section of surface height of freezing level and rain type and so on And then the vertical profile of rain rate 15 produced in accordance with the Ze R relationship a x Ze as the fundamental physical parameter of rain Input 1C21 2A21 and 2A23 the rain rate estimate is given at each resolution cell 4 km x 4 km x 250 m of PR and the average rain rate estimate between 2 altitude Zkm and 4km is calculated path averaged rain rate Additionally the calculation method and calculation accuracy of rain rate is also output b Input Data of 2A25 Processing For 2A25 processing the following input data are read from 1C21 2A21 and 2A23 4 20 TRMM DATA USERSHANDBOOK lt from 1C21 gt Scan Status Scan Time Ray Header Start Range Bin Number of Normal Sample Main lobe Clutter edge Side lobe Clutter Range Range Bin Number of Clutter free Bottom Range Bin Number of Ellipsoid Range Bin Storm Height Bin Number of Surface Peak Geolocation Information Minimum Echo Flag Normal Sample Satellite Local Zenith Angle Satellite Range lt from 2 21 gt Reliability Flag
83. 9 beam directions The precipitation radar on board the TRMM is an active phased array system radar where a transmitter and a receiver are connected to the 128 waveguide slotted antenna It carries out beam scan by controlling the phase of 128 system active array using a digital phaser so that they correspond to each beam direction The antenna pattern of the precipitation radar realizes an extremely low side lobe level through a power supply conforming to the Taylor distribution in both the along track direction and the cross track direction so as not to influence the observation precision that is caused by the strong ground surface echo which comes in from the side lobe direction of the antenna superimposing with the precipitation echo that is observed by the main beam at the same range Power supply distribution in the along track direction is realized by the way slots are cut in each of the waveguide slot antennas and the power supply distribution in the cross track direction is realized by the transmission power distribution of the 128 transmitters The precipitation radar is designed so that observation data can be obtained correctly within the satellite altitude range 350 km 402 5 km after orbit boost 7 km and 8 km Outside this altitude range a part of the received echo data may go missing or ground surface echo may not be included in the observation data Observation of precipitation using a radar from space differs from precipitation ra
84. API Application Programming Interface EOS Earth Observing System APID Application Process Identification EOSDIS EOS Data and Information System APS Antenna Pointing System NASA ARC Active Radar Calibrator EPV Endpoint Vector ARM Atmospheric Radiation Measurement ERBE Earth Radiation Budget Experiment ASCII American Standard for Computer and ERBS Earth Radiation Budget Satellite Information Interchange EROS Earth Resources Observation System ATBD Algorithm Theoretical Basis Document USGS AVHRR Advanced Very High Resolution ESA Earth Sensor Assembly Radiometer ESA European Space Agency B ESDIS Earth Science Data and Information System BDS Browse data Distribution Subsystem ETS Engineering Test Satellite BDS Bi Directional Scans EVD Engine Valve Driver BPF Band Pass Filter F BRF Band Rejection Filter FCIF Frequency Converter IF unit Floppy Disk C amp DH Command and Data Handling Subsystem FDD Flight Dynamics Division NASA CADS Catalogue data Distribution System FDDI Fiber optic Data Distribution Interface CAMS Climate Assessment and Monitoring FDF Flight Dynamics Facility NASA System FOT Flight Operations Team NASA CCSDS Consultative Committee for Space Data FOV Field of View Systems FTP File Transfer Protocol CD Compact Disc G CERES Clouds and Earth s Radiant Energy System GCI Geocentric Celestial Inertial CIR Circulator GDPF Generic Data Products Format
85. ASA S C Spacecraft NCEP National Centers for Environmental S N Signal to Noise Prediction SA Solar Array NCSA National Center for Supercomputing SADA Solar Array Drive Assembly Applications 1 2 TRMM DATA USERSHANDBOOK SADDS Solar Array Deployment and Drive W System WFF Wallops Flight Facility SARB Surface and Atmospheric Radiation WGS World Geometric System Budget WRS World Reference System SCDP System Control Data Processing WS Workstation SCF Science Computing Facility NASA WSC White Sands Complex SCID Spacecraft Identifier WWW World Wide Web SDF Standard Data Format x SDOC Science Data Operations Center NASA XMTR Transmitter SDPF Sensor Data Processing Facility NASA SDS Scientific Data Set SFDU Standard Format Data Unit SGI Silicon Graphics Incorporated SH LP Safe Hold Low Power SMS Schedule Management System SMSS Schedule Management Subsystem SN Space Network SNR Signal to Noise Ratio SOC State of Charge SOCC Science Operations Control Center NASA SP Signal Processor SPRU Standard Power Regulator Unit SSF Single Satellite Flux SSLG Standing Senior Liaison Group Special Sensor Microwave Imager SSPA Solid State Power Amplifier STDN Spaceflight Tracking and Data Network STR Structure SW Shortwave T T R Transmitter Receiver TACC Tracking and Control Cente
86. B Hitschfeld Bordan at five incidence angles 0 5 10 15 and mean of 49 angle bins Same as the above but for subset Mean and standard deviation of PIA which is not correcting rain attenuation at five incidence angles 0 5 10 15 and mean of 49 angle bins Same as the above but for subset Mean and standard deviation of PIA which is calculated by using hybrid method of SRT and HB at five incidence angles 0 5 10 15 and mean of 49 angle bins Same as the above but for subset lt Height of Bright Band Height of Storm Top Snow Depth etc m The following parameters are output for both 5 x 5 and 0 5 x 0 5 grid Height of Bright Band bbHtMean Dev bbHeightMean Dev2 Height of Storm Top stormHtMean Dev stormHeightMean Dev2 Mean and standard deviation of bright band height BbHtMean and Dev are ones for 5 x 5 grid BbHeightMean and Dev are ones for 0 5 x 0 5 grid Mean and standard deviation of storm top height conditioned on rain type StormHtMean and Dev are ones for 5 x 5 grid StormHeightMean and Dev2 are ones for 0 5 x 0 5 grid 4 29 Section4 OUTLINE OF THE TRMM PRODUCTS Snow Depth sdepthMeanl Devl Mean2 Dev2 Mean and standard deviation of snow depth only when bright band is present SdepthMeanl and Dev are ones for 5 x 5 grid Mean2 and Dev2 are ones for 0 5 x 0 5 grid The following parameters are defined
87. Calibration measurements in counts Hot load measurement data and cold sky measurement data The angle between the local pixel geodetic zenith and the direction to the satellite This angle is given for every twentieth high resolution pixel along a scan pixel 1 21 41 201 208 Brightness temperature which is observed by low resolution channels 10 GHz 19 GHz 21 GHz and 37 GHz This value 1 reduced by 100 K and multiplied by 100 Brightness temperature which is observed by high resolution channel 85 GHz This value is reduced by 100 K and multiplied by 100 c Relationship with Other Algorithms The output of 1B11 is used for 2A12 2B31 and 3A11 2 2A12 Processing a Objective The objective of the 2A12 algorithm is to reconstruct the vertical distribution of vapor cloud and rainfall etc on a pixel by pixel basis This is accomplished by comparing the measured brightness temperatures in all nine TMI channels to pre calculated brightness temperatures corresponding to cloud model profiles b Processing Description The processing diagram is shown in Figure 4 1 9 The algorithm assigns a surface type land water mixed and others to each pixel A 4 km data base is adequate for this purpose For each pixel the data base is searched for not only the central location but for surrounding grid points as well The number of surrounding grid points depends upon the surface type of the central loca
88. ECS Core Metadata 10 008 bytes PS Metadata 10 000 bytes Gridstrueture S000 bytes Precipitation 4 bytes Relative Error 4 bytes Array x nlon Data Cranale Arey nlat x nlon Planetary Gnd Figure 4 2 20 Data Format Structure for 3B43 491 Section4 OUTLINE OF THE TRMM PRODUCTS 4 3 TSDIS Tool Kits Tool kits for science algorithms software developers enable the easy incorporation of science algorithm software into TSDIS and EOC computer environments Science algorithm software modules are also developed on a computer other than the algorithm developer s TSDIS home computer environment and incorporation into TSDIS systems test environments and operating production environments is achieved after development takes place In these cases the tool kits perform a bridging function to negate the differences in computer environments allowing the same source codes to be compiled and executed without amendment Tool kits are made up of a set of libraries which have several functions Despite different function details for the various environments application program interfaces are independent in each environment Calling up the same functions in the same parameter in different environments will give the same result even if internal codes are different As well as masking differences in environments tool kits also provide function to isolate the TSDIS system resource handling from the software developer This mea
89. ECS Project 170 TP 005 003 April 1997 I Getting Started with HDF Draft Version 3 2 May 1993 University of Illinois at Urbana Champaign 2 Related Sites over Internet URLs of the homepages related to TRMM are listed below a JAXA Homepage http www jaxa jp index_e html 0 EOC Homepage http www eoc jaxa jp EORC Homepage http www eorc jaxa jp index html a TRMM Homepage EORC http www eorc jaxa jp TRMM b Orbit Viewer Download JAXA EORC http www eorc jaxa jp TRMM document orbitviewer index htm d NICT Homepage http www nict go jp overview index html a Microwave Remote Sensing Section Homepage NICT http www2 nict go jp dk c21 1 index e html A2 2 TRMM DATA USERS HANDBOOK e RESTEC Homepage http www restec or jp restec e html NASA Homepage http www nasa gov NASA GSFC Homepage http www gsfc nasa gov a TRMM Homepage http trmm gsfc nasa gov b TRMM Science Data and Information System TSDIS Homepage http tsdis gsfc nasa gov tsdis tsdis html c TRMM Satellite Validation Office Homepage http trmm fc gsfc nasa gov trmm gv index html d NASA EOS Homepage http eospso gsfc nasa gov CERES Online Documentation NASA LaRC http asd www larc nasa gov ceres trmm LIS Homepage NASA MSFC http thunder msfc nasa gov NCSA HDF Homepage http hdf ncsa uiuc edu NCSA anonymous ftp Server ftp ncsa
90. El Nino said as the century maximum appeared in 1997 and became a maximum term in December On the other hand TRMM was launched in November 1997 and PR observation started from December Therefore TRMM couldn t observe this El Nino in the period when it appeared As for the Nino and the La Nina which is that opposite phenomenon magnitude changes every time Then some times of El Nino La Nina observation is necessary to search for that fluctuation factor Therefore a precipitation observation mission following to TRMM is necessary to get the rainfall distribution and time fluctuation for longer period There is the second peak in the medium latitude area as for the rainfall though there is the biggest peak of course in the tropical area when it averages the rainfall of the world in the longitude direction and only latitude distribution is seen The second peak is caused by the precipitation by the low pressure of the medium latitude Low pressure like a typhoon appears with Okhotsk Ocean in Japanese winter and active cumulus activities are accompanied with it The observation 6 17 Section6 TRMM OPERATION STATUS RESULTS and FUTURE PLAN area of TRMM doesn t cover these activities When the water circulation is grasped globally it is necessary to do observation including the peak of the precipitation distribution of the temperate zone and the subpolar zone Latent heat emission due to the precipitation activities influence the c
91. HE TRMM SATELLITE 2 5 2 1 PR The PR instrument requires little day to day commanding Immediately after the launching of TRMM external calibrations were performed approximately every two months and internal calibration once a week respectively However the frequency of external calibrations has been decreased as PR became stable At present external calibrations are performed once every six months for the year 2005 On the other hand internal calibrations were automated how internal calibrations always were performed where the electric wave radiation is prohibited Therefore internal calibrations were performed about one two or three times a day at present for the year 2005 External calibration consists of two types of Antenna Pattern Measurement an along track antenna pattern and a cross track antenna pattern Nominally the along track antenna pattern measurement will be performed in the limited scan mode which uses seven of the 103 beams and disregard the remaining The Cross track will be done when an anomaly occurs on result of along track one or telemetry of SSPA or LNA Both of them must be performed when TRMM passes over an ARC located in Japan JAXA EOC will provide times and a beam number to the FOT via TSDIS SOCC The Cross track Antenna Pattern Measurement will require a 90 yaw maneuver of the spacecraft to point the Y axis towards the velocity vector The maneuver will take approximately 15 minutes maneuver and
92. HE TRMM SPACECRAFPFT isicing tene bite dad 2 1 2L Spacecraftissiacaue E ANA bere o E be He er dee dete deos 2 1 2 1 1 Command and Data Handling Subsystem C amp DH eese nennen 2 2 2 1 2 Attitude Control Subsystem ACS eene nnne these nensi tne 2 4 2 3 Electrical Subsystem ES iv be EE E E RU RR RES 2 5 2 1 4 Power Subsystem PWR e Aene 2 5 2 1 5 Radio Frequency Communications Subsystem 2 6 2 4 6 Thermal Subsystem THM eicit REO E NR ER Ee 2 7 2 1 7 Reaction Control Subsystem 2 7 2 4 6 Deployables DEP asi Eee re bag eere e LR RE epe euo Cer ee ete Meee 2 8 2 1 9 Structure Subsystem STR iimis a A E E AE EE E 2 9 2 2 Overview of the Onboard 2 10 2 21 Precipitation Radar PR uad YU E VEENA 2 10 L4 MISSION OVerVIeW EE EAA 2 10 Dde Stem Parameters 2 10 2 2 0 TRMM Microwave Imager TMI esses ae a 2 12 2 2 2 1 MISSION OVET VIEW serene nep ee nett a ein 2 12 2 2 2 2 System Parameters cse ERR HIR IER TRE IER HIR INE TO NE IE PP e Re 2 12 2 2 3 Visible and Infrared Scanner eene nnne enne 2 13 2 2 3 1 MISSION OVETVIEW espe Re p Rd a e VR EAR TL UR VOI 2 13 2 23 2 Sy
93. Hand Circular Polarization PS Power Supply LIS Lightning Imaging Sensor PSDU Power Switching and Distribution Unit LNA Low Noise Amplifier PSE Power System Electronics LOGAMP Logarithmic Amplifier PSIB Power System Interface Box LVPC Low Voltage Power Connector Q LW Longwave QAC Quality and Accounting Capsule LZP Level 0 Processed QL Quick Look M R MAM Mirror Attenuator Mosaic R amp RR Range amp Range Rate MCS Media Conversion Subsystem R T Real Time MDSS Master Data Storage System RAM Random Access Memory METEOSAT Meteorological Satellite RAP Rotating Azimuth Plane MLI Multi Layer Insulation RCS Reaction Control Subsystem MO amp DSD Mission Operations and Data Systems RDA Receiver Drive Amplifier Directorate REF Reflection MOC Mission Operations Center NASA REM Rocket Engine Module MOSDD Mission Operations and System RESTEC Remote Sensing Technology Center of Development Division Japan MSFC Marshall Space Flight Center NASA Radio Frequency MTB Magnetic Torque Bar RHCP Right Hand Circular Polarization N RIS Raster Image Set N A Not Applicable ROM Read Only Memory NASA National Aeronautics and Space RS Reed Solomon Administration RST Remote Science Terminal NASCOM NASA Communications Network RTEP Real Time Event Processor NASDA National Space Development Agency of RWA Reaction Wheel Assembly Japan currently named NASDA S NCC Network Control Center N
94. I and the Visible and Infrared Scanner VIRS while JAXA EOC develops the Level 1 processing software for PR The generation of TRMM Level 2 and Level 3 products is accomplished using algorithm software provided by TRMM science team algorithm developers Data are sent to the NASA Earth Observing System EOS Data and Information System EOSDIS for general distribution and permanent archive and to TSDIS Science Users TSUs The TSUs are the science algorithm developers TRMM instrument scientists TMI VIRS and PR and designated scientists who are charged with science data quality control Their data is provided for the general user by DAAC Distributed Active Archive Center in EOSDIS The TSDIS can be described as having three broad functions generation and transfer of TSDIS data products interaction with the TRMM and exchanging data and software with TSDIS science users These three functions are accomplished by the Science Data Operations Center SDOC the Science Operations Control Center SOCC and the Remote Science Terminal RST respectively The basic SDOC functions are e Product generation of all approved science products level 1 3 e Reprocessing at 2 days per day e Ingest from SDPF and EOSDIS e Transfer of data products to EOSDIS e Distribution of products to supported science users e Data storage for all TSDIS components e Information management and data management e Provide an integration and test environ
95. Interpolate Fluxes and Global Radiative Fluxes Compute Fluxes Clouds Averages and Clouds T 8 Figure 4 1 10 CERES Data Flow Diagram Section4 OUTLINE OF THE TRMM PRODUCTS Table 4 1 5 CERES Data Products CEROI Bi directional Scan Filtered Radiation CERO2 ES 8 L2 ERBE Earth Radiation Budget Experiment like Instantaneous TOA top of atmosphere and Surface Flux Estimate CERI3 ERBE like Monthly Geographical Averages Source ES 8 14 ES 4G L3 ERBE like Monthly Girded Averages Source ES 8 ERBE like Monthly Regional Averages Source ES 8 and cloud properties SARB modeling method CER12 L3 Hourly Girded Single Satellite TOA and surface fluxes clouds Ed parameterization method AVG RH 4 1 5 2 Processing Algorithm 1 Subsystem 1 Instrument Geolocate and Calibrate Earth Radiances The instrument subsystem converts the raw level 0 CERES digital count data into geolocated and calibrated filtered radiances for three spectral channels a total channel 0 3 200 um a shortwave channel 0 3 5 and a longwave window channel 8 12 The CERES instruments are designed so that they can easily operate in pairs as shown in Figure 4 1 11 In this operation one of the instruments operates in a fixed azimuth crosstrack scan CTS which optimizes spatial sampling over the globe The second instrument RAP scanner rotates its azimuth plane scan as it scan
96. KwriteHeader TKcopyScanHeader TKreadHeader and TKwriteHeader read and write the ray header for PR L1B21 and 4 94 TRMM DATA USERSHANDBOOK L1C21 data products and read and write clutter flags for L2A25 PR data products TKcopyScanHeader will copy elements of the swathdata structure from the specified input granule to the specified output granule 4 3 2 Conversion Tool Kit The constants and conversion factors consist of physical constants such as earth radius factors for converting between degrees and radians and time conversion routines reused from the ECS PGS toolkit 4 95 Section4 OUTLINE OF THE TRMM PRODUCTS 4 3 3 Geolocation Tool Kit Geolocation Tool kit is used for calculating the longitude and latitude of observation points Table 4 3 2 shows the module structure within the tool Table 4 3 2 Module Structure Outline of Processing GEOinitGeolocation GEOgetModelParams Reads sensor and the earth s model parameters m eee unit IFOV vector beam direction vector tables for all pixels angle bins in one scan the satellite position and velocity vector at orbit start time with GCI geocentric inertial coordinates system GEOgetOrbElem Calculates six Keplerian orbital elements from satellite position and velocity vectors at orbit start time GEOProcessGeolocation getACSpacket Extracts the ACS data packet closest in time to the given scan time from the LIA file GEOreadACS Data GEOge
97. LIS data is stored in HDF Vgroups Vdatas Vsets 1 sets of Vdata and Scientific Data Sets SDSs using the version 1 EOS HDF Standard Data Format SDF The LIS data for a single orbit is stored in two HDF files one containing the major science and the other the background images This is done so users who are not interested in the background images do not have to download the large background files to get to the lightning data The HDF file structure describes the data such that a user utilizing an HDF file reader can read and process the orbit granule data The actual data are stored in Vsets and Vgroups Indexes are maintained within the Vgroups to link the various Vsets The file name starts with the platform name TRMM followed by the instrument name LIS file type designator SC for science data and BG for background image data version number VV a period and the revision number R After the revision number the file name contains the year Y Y Y Y day of year DDD and the orbit number ORBIT of the data The HDF file components are illustrated in the Figure 4 1 12 for both Science and Background file 4 56 TRMM DATA USERSHANDBOOK Moreover Table 4 1 6 shows the outline of the LIS Data products TRMM LIs SC NVRE PY EDD OR BIT Deive d Poim Summary V XE Viewtime i Vs LIS BGR VOD ORBIT Summary aL Hi Summary Wa Chhit V ji piia Hg Or
98. Level 3 Monthly Rainfall Products a Output of 3A25 3A25 computes monthly mean rain rate from PR Level 2 data at both a low horizontal resolution 5 x 5 latitude longitude for near surface and five vertical layers and a high resolution 0 5 x 0 5 latitude longitude for near surface and three vertical layers Note that Figure 6 3 3 2 low resolution and Figure 6 3 3 3 high resolution show monthly accumulated rainfall calculated from original data in order to compare with other Level 3 products b Output of 3B31 3B31 uses the high quality retrievals done for the narrow swath in combined Level 2 2B31 data to calibrate the wide swath retrievals generated in TMI Level 2 2A12 data It calculates monthly accumulated rainfall at each 5 x 5 latitude longitude box for near surface Figure 6 3 3 4 and 14 vertical layers Monthly accumulated rainfall at each 5 x 5 latitude longitude box for near surface Figure 6 3 3 5 and 14 vertical layers calculated from 2B31 is also included c Output of 3B43 d 3B43 provides a best precipitation estimate in the TRMM region from all global data sources namely TRMM geosynchronous IR and rain gauges at each 1 x 1 latitude longitude 0 25 x 0 25 product version 6 Note that Figure 6 3 3 6 shows monthly accumulated rainfall calculated from original data monthly mean in order to compare with other Level 3 products r a m i L i aT m i
99. Linux computers The following functions are included in this release as of March 2005 Furthermore generally this toolkit is shown in the TSDIS home page and science users can access TRMM data in addition to algorithm developers by installing in UNIX environment In this section tool kit routine was roughly introduced and in the following section the outline of some tool kits such as I O toolkit Conversion tool kit and Geolocation toolkit are explained The latest status about tool kit is provided from the Toolkit Fast Fact Information on TSDIS home page http www tsdis gsfc nasa goc tsdis tsdistk html 4 3 1 I O Tool Kit The Input and Output routines are designed to make it easy for the Algorithm Developer to access TRMM data The routines are listed below and fall into several classes File Access Data Access Scan Data Access Grid Data Access Level 1 GV Metadata Access Header Access and Ancillary Data Access 4 93 Section4 OUTLINE OF THE TRMM PRODUCTS File Access TKopen TKseek TKclose TKendOfFile TKopen opens a file for reading or writing Tkclose closes a file TKseek moves the file pointer to a specified scan in the file TKendOfFile signals when an end of file condition has been reached Data Access Scan TKreadScan TKwriteScan TKreadScan reads a single scan from an opened file containing scan based satellite data TKwriteScan writes a single scan to an opened file containing scan b
100. MOL 2 38 2 6 4 Outline of the eene enne enne enne teretes etes ener 2 40 2 6 5 Explanation of the Components eese ARE ENRE STEERER ETARE ETTER 2 42 2 6 5 Antenna SUBSYSTEM de tee uae neue late Eee 2 42 2 6 5 2 Transmit Receive Subsystem sorisa as a E tenente enne enne 2 44 2 6 5 3 Signal Processing Subsystem eese esent nennen nennen etre nennen 2 46 CONTENTS 4 2 6 5 4 Structure Subsystem 2 50 26 93 OI DE 2 50 2 6 0 Observation Model i RE EB ER RE E RE RR ERES 2 51 2 0 6 1 R diometnie Model isis teu due ite ie tei ed en rein ie tree inii 2 51 2 6 6 2 Observation Range Model ti eee e etie teens 2 51 2 6 6 3 Geometric Model eee ee ET UE E E RES 2 53 2 7 Operation of Post Orbit BOOS hoto tana ar a a AE AT A 2 55 2E OBaCKorOWllduissi denied t TOV o etn RE Vet desi d 2 55 2 72 Change of Orbit Parameter 2 55 2 3 Op ratiom OF PR ie eie eer t ee e cb 2 56 2 74 Mismatch of Transmit to Receive Angle eese eee eene nenne nne nennen 2 56 279 dnfiuence on Other Sensors 2 56 2 56 Attitude Control Systenis ie t d o io He n i d d n e o d d dede 2 56 OUTLINE OF THE GROUND SYSTEMS 3 1 3 1 TRMM Total Ground System 3 1 3 2 TRMM Preci
101. Monthly Oceanic Rainfall Cloud Ice Water 2 bytes Array Precipitation Ice 2 bytes Array nscan ngeo x npixel x nscan nscan nscan npixel npixel npixel npixel npixel npixel nlayer 2 nlayer gt nlayer gt nlayer nlayer The 3A11 is grid data and it is stored in the Planetary Grid structure 5 x 5 Figure 4 2 15 shows the structure of the 3A11 product in terms of the component objects and sizes nscan nscan nscan c nscatn hscan nscan npixel x npixel x npixel npixel 3 npixel nscan nscan nscan nscan nscan TRMM DATA USERSHANDBOOK ECS Core Metadata 10 000 bytes PS Metadata 10 000 bytes Data Granule GiridStructure 000 bytes Monthly Rainfall 2 bytes Array Number of Samples 4 bvtes Array niat x Chi Square Fit Array nlat x Freezing Level 2 bytes Array 2bytes Array u r 2 bytes Array nlat x PlanetarvGrid Sigma r 2 bytes Array nlat x Probability of Rain vies Array nlat x Duality Indicator Array nlar x nlon Quality Indicator 2 2bytes Array nlat x nlon Quality Indicator 3 x nlon Array Figure 4 2 15 Data Format Structure for 3A11 4 2 4 3 VIRS 1 1B01 Radiance The 1 01 is stored as Swath Structure in HDF The following sizing pa
102. Network Control Center NCC e Flight Dynamics Facility FDF e Sensor Data Processing Facility SDPF e TRMM Science Data and Information System TSDIS e Langley Research Center LaRC e Marshall Space Flight Center MSFC e Space Network SN e Wallops Flight Facility WFF The following sections provide a brief functional description of the ground system elements supporting TRMM 3 15 Section3 OUTLINE OF THE GROUND SYSTEMS eje suryoul UPO A WO WHU 204 vjeq uonrsm boy VXVI VSVN 25 YOO YOMND 477 ALLS weq uonrsmboy vjeqsupjoer L sdqx c sdqy p701 PZOT ewa so Seu IWMYO 10814 Attitude Data TRMM Phnning Aids Vectors Ephemerices TRMM Orbit Data Amou y pue sogesso A WW Lompa SAAL ae 477 sdgIN 80 c wyo yor gke q Pre oquo sig SINGO SUL OJON 1a TI eye Ajouropo LA SAAL 5 SAAL SUAL EE E EA eyeq uonismboy 8 2 EE E SWO SAAL 0159 5 lt SINGO SUGL noddng fous SIO UW J N a 5956559 IN ANPIYIS SAAL aeq uonrsmboy JSM al a 2 TI SUDO SUI JON CET E WAAL yorg amp e q preoquo
103. OS B EOS B dO RU COUR 4 47 TRMM DATA USERS HANDBOOK ATS Product Definition cay steed saeeyes 4 47 4 1 5 2 Processing Algorithm eee e RC eas e veh de 4 50 ALOA LIS So epi Re e I e Ae n E e an RE e 4 56 4 1 6 1 Produet Definitions tele 4 56 4 1 6 2 Processing Algorithms suiit E Ep Te CH epe o Pre epe eee du 4 57 42 BDE Format eee PP ET T GE re TUI PRATER 4 67 424 Outlin of cn ae ERE ue ERE LEE aiu 4 67 422 EOSDIS SITUGIUFES Set eo e et te Uo o eie ot 4 69 4 2 2 1 Swath Structure coerente see 4 69 4 2 2 2 Planetary Grid Str cture icu a rere e odes 4 70 42 3 Formatting Conventions IS ec E CRY GNE VIEW EG I VERE 4 72 FUCASTFUCTULE pe pe e RR Re e Eee atre S 4 72 4 2 3 2 Fle Contents ici pee deb d te rre eto eode ee ient 4 73 4 2 3 8 Missing Data meriti 4 73 4 2 3 4 Array Dimension Orr i e ete ee e terrre ren Ee ren een Ern ea 4 74 4 2 3 5 Orbit and Granule Definition esses eee ener enne nnne nnne 4 74 42 3 06 Scans qna Gran le i eter 4 75 LIS e Cre dde te Re 4 75 4 2 3 60 DAC Error Lybe s eoe oo PARERE REESE 4 78 4 2 4 Structure of TRMM Data Products eese eene eene nennen nennen erinnern 4 78 PR i dade teil tie e re Ce en Gem Ope se dete ep
104. Order Rain Rate Three statistics mean standard deviation Probability of zeroOrderFit distribution fit of the rain rates as derived from the 0 Order method at 2 km 4 km 6 km and path average HB Rain Rate Same as above except HB method used for rain rate estimates hbFit 2A25 Rain Rate Same as above except data from 2A25 are used for rain rates Fit2A25 estimates d Reliable Coefficient The reliability factors are calculated for three statistics mean standard deviation Probability of distribution fit and for each method 0 Order HB and Hybrid 2A25 The metadata in 3A26 products are the same as those in 1B21 Core metadata and PS data d Relationship with Other Algorithms 3A26 is the final product and is not input to any other algorithms 4 1 1 3 Data Usage PR can observe vertical profile of rain structure It is unique data and can not be directly acquired by the other instrument PR is the world s first precipitation radar for installation on artificial satellites and its processing algorithm is also first time in the world PR products processed by the algorithm are validated by using comparison with the well corrected ground radar data and are used in combination with the observation data of TMI and VIRS and are utilized to achieve the primary goal of TRMM which is to estimate monthly average rain rate within 10 error for 5 x 5 grid Level 1 processing results 1A21 1B21 1C21 are converte
105. R nscan is calculated from the average number of seconds in an orbit as follows NSCAN SS x SO For TMI nscan is calculated from the average number of seconds in an orbit as follows NSCAN 55 SO 100 where INSTRUMENT SCANS SECOND SS SECONDS ORBIT SO NSCAN TMI 31 600 60 5490 299 VIRS 2 98 5 60 5490 18026 1 0 6 5490 9150 4 2 3 7 Time Scan Times and Orbit Start Times are stored in the Level 1A headers the metadata and in the object named Scan Time The Orbit Start Time is determined from ephemeris data and the definition of the orbit start it is independent of any scans In contrast a Scan Time is a time associated with a scan of a particular instrument The Scan Time is the time tag stamped on each science telemetry packet In particular the Orbit First Scan Time is the Scan Time of the first scan in an orbit which occurs at or later than the Orbit Start Time The Level 1A header stores 4 75 Section4 OUTLINE OF THE TRMM PRODUCTS the Universal Time Correlation Factor UTCF derived from the first ACS packet in the orbit This UTCF is used to translate the Orbit Start Time from UTC to spacecraft clock time In normal processing the UTCF the Scan Times in UTC and the Scan Times in spacecraft clock time are repeated exactly in Level 1B and higher levels In the unusual circumstance that the UTCF is found to be incorrect a corrected UTCF will be stored in Level 1B and higher data produ
106. Receive decommutate process and display all real time telemetry for observatory spacecraft subsystems and instruments health and status monitoring e Receive and process Level 0 data files from the SDPF for off line trend and performance analysis of spacecraft housekeeping systems e Process playback data to determine the number of missing telemetry frames command retransmission of missing playback data in real time e Record real time history data during all daily operational events and retain for approximately 30 days e Provide interface with the Network Control Center NCC for the Tracking and Data Relay Satellite TDRS resource requests and schedule coordination e Provide interfaces with instrument facilities for exchange of data and other information required to operate and monitor the instruments including remote displays e Provide maintenance of the Project Data Base PDB 3 4 2 NASA Communications Nascom serves as the hub for data and voice communications amongst the supporting elements of the mission Data and voice links required to accomplish all real time and off line activities from pre launch testing throughout the mission lifetime are provided by Nascom In addition to institutional services data and or voice activities to external science agencies TSDIS LaRC MSFC and JAXA EOC are provided and maintained by Nascom 3 17 Section3 OUTLINE OF THE GROUND SYSTEMS 343 Network Control Center NCC The NCC is
107. SA ftp server Some of these utilities are described in 4 4 422 EOSDIS Structures TRMM data products have adopted HDF EOS format HDF EOS is one of extension format and developed for EOSDIS This format provides some new data model to apply satellite data 4 2 2 1 Swath Structure The swath structure was created by EOSDIS to store satellite data which are organized by scans TSDIS implements the swath structure in Levels 1B 1C 2A and 2B satellite products Figure 4 2 3 shows a generic swath structure as it is used in TSDIS data products The swath structure is contained in a Vgroup with the name SwathData and the class SwathData In the SwathData 469 Section4 OUTLINE OF THE TRMM PRODUCTS Vgroup are SwathStructure Scan Time Geolocation scan data and IFOV data For all of these objects the scan dimension has the least rapidly varying index Each object is defined in the following SwathStructure A text block which specifies which geolocations and times apply to which elements of the IFOV data Scan Time Vdata 8 byte float or several integers whose sizes sum to 8 bytes Geolocation An SDS containing latitude and longitude 4 byte float Scan data It applies to the whole scan and can take the form of one or more Vdatas SDSs IFOV data occurs at every pixel or at regular pixel intervals e g every 10 pixels and takes the form of one or more SDSs
108. Signals Bus power supply Local Signals Figure 2 6 8 Operation of PLO when FCIF A System is turned on b Function 1 Supplies a local signal of a constant frequency to the in service FCIF 2 Itis turned on at the same time that power to FCIF is turned on 2 49 Section2 OUTLINE OF THE TRMM SATELLITE 2 6 5 4 Structure Subsystem Structure subsystem supports the components and others which make up the precipitation radar system 2 6 5 5 Others Thermal control subsystem maintains and controls the temperatures of each part of the precipitation radar within the tolerance level Thermal control method of the precipitation radar is made up of passive thermal control systems such as MLI OSR heat sink and coating materials and active thermal control systems such as heater and heat pipe Heater control is by the mechanical thermostat in the panels mounted on the precipitation radar instruments The precipitation radar is thermal controlled on the precondition that it is independently thermal controlled from the TRMM observatory itself To carry out independent thermal control the design was to avoid heat radiation heat transfer bonding between the radar and the TRMM observatory itself as much as possible For this reason heat sinking planes are positioned on the Y plane panels and the antenna section which have a small thermal interference with the TRMM observatory The perimeter of the precipitation radar not positi
109. TCF have the same format Spacecraft clock time is the accumulated time count since the power up of the clock card in the TRMM Spacecraft Data System onboard the satellite Spacecraft time is correlated to UTC time by the UTCF The sum of the UTCF and Spacecraft time results in a time that represents the total number of seconds since January 1 1993 at 00 00 00 UTC if one assumes that each day has exactly 86400 seconds even days with leap seconds This total number of seconds allows easy computation of days since January 1 1993 Scan Time is a time associated with each satellite science data scan It is the time tag written in each science telemetry packet There is one scan per science telemetry packet The relationship of Scan Time to the time at each IFOV varies by instrument A description of the relationship between Scan Time and measurement time for each of the three satellite instruments follows In each description T is the beginning sample time and i is the IFOV number 1 For TMI the equations shown in Table 4 2 2 were obtained by personal communication with the instrument scientist Table 4 2 2 TMI Equations CHANNEL RELATIONSHIP INDICES SAMPLE TIME 1 2 10 GHz Scan Time 59 185 ms i 1 6 600 ms i 110104 6 304 ms 3 4 5 T Scan Time 125 544 ms 1 1 6 600 ms 1 110104 6 266 ms 19 21 GHz 6 7 37 GHz Scan Time 125 544 ms i 1 6 600 ms 1 110104 16 304 ms 8 9 85 GHz
110. TDRS events where recorder playbacks are scheduled all TDRS events will take precedence over any event that would inhibit science data collection on the ground 4 180 yaw maneuver 5 Delta V maneuver 6 Any rain instrument science activity including anomaly troubleshooting for science performance This includes the PR Antenna Pattern Measurement 90 yaw 7 Any CERES or LIS instrument science activity including anomaly troubleshooting for science performance This includes the CERES Deep Space Calibration The JAXA EOC will have the primary responsibility for PR instrument planning Planning aids will be accessible to the EOC via the SOCC for PR instrument planning All PR operation requests are checked by the EOC to verify that they will not be within PR operations constraints before the activity time The EOC will then send instrument activity requests and information to the SOCC for transfer to the FOT for incorporation into the DAP Basic conflict resolution if necessary will be coordinated between the FOT and SOCC with the EOC being represented by the SOCC personnel For the scheduling of PR external calibrations the JAXA EOC will provide times corresponding to when the TRMM spacecraft will pass over the Active Radar Calibrator ARC External calibration commands will be placed into the daily command load along with commands for an internal calibration Requests for the PR Antenna Pattern Measurement must be made by the PR
111. TRMM Data Users Handbook de m GOES METEOSAT IH by JWA F Japan Aerospace ail Exploration Agency Earth Observation Center TRMM Data Users Handbook Japan Aerospace Exploration Agency Earth Observation Center Global environment change has become worldwide concern in recent years Satellite remote sensing is recognized as a powerful and essential means for monitoring global change of earth environment The Tropical Rainfall Measuring Mission TRMM is a joint mission between US and Japan and it is the first satellite earth observation mission to monitor tropical rainfall which closely influences to global climate and environment change TRMM was launched by the H II rocket from the then NASDA National Space Development Agency of Japan From October 2003 on re organized as JAXA Japan Aerospace Exploration Agency Tanegashima Space Center in November 1997 and has gone into a circular orbit of altitude 350 km inclination angle 35 and period 90 min After launch rainfall observation from TRMM was started and the designed routine operation period of 3 years was finished at the end of January 2001 And in order to extend observation period the satellite altitude was raised to about 400km in August 2001 and its mission life is planned until September 2009 TRMM observation data are received at the NASA ground station via Tracking and Data Relay Satellite TDRS and some of observation dat
112. Tee COMB 3 531 irem 2831 E mE r TTA MNT ar CH A d 1 SASS 2 Fay 3B43 TRAMM A Other Data Sources 0 I a Figure 6 3 3 Example of TRMM Level 3 Monthly Rainfall Products May 2000 611 Section6 TRMM OPERATION STATUS RESULTS and FUTURE PLAN 6 4 Utilization of TRMM Data 1 Observation Result of El Nino Figure 6 4 1 shows the global rainfall distribution for January 1998 upper panel and January 1999 lower panel observed by the PR Differences of rainfall distribution due to El Nino are clearly seen in these figures In January 1998 upper panel since El Nino still continued heavy rainfall areas in the Pacific shifted from the western to the central Pacific unlike the normal year Due to the effects of El Nino the inter tropical convergence zone ITCZ was located along the Equator in the upper panel and areas of heavy rainfall in the south Pacific shifted further to the east than in the normal year The lower panel shows the rainfall distribution in January of this year at this time the EI Nino event was already finished Unlike the upper panel rainfall amount was small in the central equatorial Pacific and the ITCZ existed in normal location In addition large amount of rain was observed in Indonesia and the center of active convection was observed in its normal location Figure 6 4 2 shows the Sea Surface Temperature for El Nino year January 1998 upper pane
113. a are transmitted from NASA Goddard Space Flight Center GSFC to JAXA Earth Observation Center EOC Those data are distributed from EOC to users such as research institute and so on And many scientific successes have already been achieved from the data about the 3 dimensional structure of the rain obtained by TRMM until now By extension of mission life it is expected that the TRMM data is further used broadly over a long period The purpose of this handbook is to provide users with necessary information for well and spread utilization of TRMM data We wish TRMM data with this handbook contribute your studies on earth environment preservation enhancement of climate change analysis and so on In closing I would like to express my gratitude for assistance given by the PIs National Institute of Information and Communications Technology NICT Remote Sensing Technology Center of Japan RESTEC and Earth Observation Research Center EORC personnel who contributed their busy time April 2006 Earth Observation Center Japan Aerospace Exploration Agency TRMM DATA USERS HANDBOOK TRMM Data Users Handbook Contents I ZNIRODUGLIION osuere c mia ated te 1 1 I Purposes niente nation nci te ite er E 1 1 EDs SCOP ences A psi esie peeing iei ghe envie cei celi E emend 1 1 LS 1 2 1 4 Responsibilities of US and Japan 1 3 2 OVERVIEW OF T
114. accumulated rainfall at each 5 x 5 grid for near surface and 14 vertical layers TRMM amp IR Daily Rainfall provides precipitation estimates in the TRMM regions that have the nearly zero bias of the TRMM Combined Instrument precipitation estimate and the dense sampling 0 25 x 0 25 of geosynchronous IR imagery TRMM and Others Data Sources Monthly Rainfall provides a best precipitation estimate in the TRMM region from all global data sources namely TRMM geosynchronous IR SSM I microwave and rain gauges 4 1 4 2 Processing Algorithm The algorithm for COMB data products in Table 4 1 4 is explained hereafter The structure of 1B01 product is described in the later section 4 2 4 4 TRMM DATA USERSHANDBOOK 1 2B31 Processing a Processing Description 2B31 processing is to calculate the correlation corrected mass weighted mean drop diameter coefficient of rain attenuation correction rain rate and PIA by using PR data and TMI 10 GHz channel data Standard deviation of each parameter is also calculated b Input Data of 2B31 Processing For 2B31 processing the input data are read from TMI 1B11 2A12 and PR 1C21 c Output Data of 2B31 Processing The outputs of 2B31processing are listed in below D hat mm Normalized unit D hat is the correlation corrected mass weighted mean drop dHat diameter RMS uncertainty in D hat is also recorded as Sigma D sigmaDHat hat R hat
115. accuracy In this sense it would be necessary to calibrate the ISCCP cloud properties against the TRMM and EOS cloud properties We are currently performing sensitivity studies on the utility of the ISCCP cloud properties for this purpose 8 Subsystem 8 Monthly Regional Zonal and Global Radiation Fluxes and Cloud Properties ATMOSPHERE Data Product This subsystem uses the CERES instantaneous synoptic radiative flux and cloud data subsystem 7 and time averages to produce monthly averages at regional zonal and global spatial scales Initial simulations using both 1 hourly and 3 hourly data have shown that simple averaging of the 3 hourly results is adequate for calculating monthly average LW fluxes SW flux averaging however is more problematic The magnitude of the solar flux diurnal cycle is 10 to 100 times larger than that for LW flux Two methods for SW time averaging are currently being tested using Release 2 data The first method uses the same techniques as subsystem 7 but to produce 1 hourly instead of 3 hourly synoptic maps Time averaging then proceeds from the l hourly synoptic fields The second method starts from the 3 hourly synoptic data and then time interpolates using methods similar to ERBE for other hours of the day with significant solar illumination While the use of models of the solar zenith angle dependence of albedo are adequate for TOA and surface fluxes we will examine extensions of these techniques to includ
116. adir direction Histogram of bright band width from nadir direction Histogram of bright band maximum Z from nadir direction The following parameters are calculated only when rain rates at 2 km 4 km and 6 km are all non zero and are output for only 5 x 5 grid Rain Rate rainCCoef Stratiform Rain Rate stratRainCCoef Convective Rain Rate convRainCCoef Correlation coefficient of rain rate at height 2 km 4 km 2 km 6 km 4 km 6 km for all rain type Correlation coefficient of rain rate at height 2 km 4 km 2 km 6 km 4 km 6 km for stratiform rain Correlation coefficient of rain rate at height 2 km 4km 2 km 6 km 4 km 6 km for convective rain The following parameters are calculated for only 5 x 5 grid only when all three PIAs exist and are reliable or marginal 4 32 TRMM DATA USERSHANDBOOK PIA Correlation coefficients of six kinds of PIA values which put piaCCoef together two PIAs in HB SRT Oth K Z relation is supposed from Zm which is not correcting rain attenuation And PIA is calculated to integrate it and standard output of 2A25 The metadata in 3A25 products are the same as those in 1B21 Core metadata and PS metadata d Relationship with other algorithms 3A25 is the final product and is not input to any other algorithms 8 3A26 a Processing Description 3A26 processing is to compute monthly rainfall rain rate averages r
117. ain R Z relation Parameter YzA1 B1 A2 B2 Stratiform Rain R Z relation Parameter rzStratA1 B1 A2 B2 Convective Rain R Z relation Parameter rzConvAl1 B1 A2 B2 Estimated mean and standard deviation of rain at range gate to surface rain certain only Same as the above but for stratiform rain Same as the above but for convective rain Mean and standard deviation of shallow rain Mean and standard deviation of shallow isolated rain Mean and standard deviation of epsilon on convective rain which is calculated in 2A25 processing Mean and standard deviation of epsilon on stratiform rain which is calculated in 2A25 processing Mean and standard deviation of epsilonO on convective rain which is calculated in 2A25 processing Mean and standard deviation of epsilonO on stratiform rain which is calculated in 2A25 processing The parameter in rainfall reflectivity relation AZ B from fitting of instantaneous R Z pairs Same as the above but for stratiform rain Same as the above but for convective rain lt Radar Reflectivity Factor 7 gt mm m For 0 5 x 0 5 grid only mean values are output Un corrected rain attenuation Z Zm zmMeanl zmDev1 zmMean2 Mean and standard deviation of radar reflectivity factor Zm including rain attenuation each layer path average conditioned on rain Zm Stratiform Rain Rate stratZmMeanl stratZmDevl stratZmMean
118. ain rate standard deviation and probability distribution function for 5 x 5 grid at three layers 2 km 4 km and 6 km and path average by the Multiple Threshold Method b Input Data of 3A26 Processing For 3A26 processing the input data are read from 1C21 2A21 2A23 and 2A25 c Output Data of 3A26 Processing As 3A26 output the following data is calculated in lon lat 5 x 5 region grid These grids cover the area of 40 N 40 S x 180 E 180 W and the number of grid is 16 x 72 a Probabilities of Rain Total Counts Total number of observation per month at each 5 x 5 grid This is ttlCount calculated at 2 km 4 km 6 km and path average Rain Counts Total number of rain observation per month at each 5 x 5 grid rainCount This is calculated at 2 km 4 km 6 km and path average b Probability Distribution Function of Rain Rate 0 Order Rain Rate Probability density function in counts of the 0 Order rain rate zeroOrderpDf estimate at each 5 x 5 grid This is computed at 2 km 4 km 6 km and path average For of limit value following values of six are used 0 1 0 2 0 3 0 5 0 75 and 0 999 HB Rain Rate Same as the above but for HB rain rate estimate hbpDf 2A25 Rain Rate Same as the above but for 2A25 rain rate estimate using hybrid pDf2A25 method of SRT and HB 4 33 Section4 OUTLINE OF THE TRMM PRODUCTS c Mean Standard Deviation and Probability 0
119. ameter b of relationship equation between rain rate and Z factor Ze b is given at five nodal points and b values between the nodes are calculated by linear interpolation 4 23 Section4 OUTLINE OF THE TRMM PRODUCTS In 2A25 product moreover the same information as 1B21 is recorded about Meta data Scan time Geolocation Scan status and Navigation However the following five metadata fields are copies of the five parameter fields used by the 2A25 algorithm at runtime Algorithm ID Total scan number Algorithm version number only in EOC products Product version number only in EOC products d Relationship with Other Algorithms The output of 2A25 is used for 3A25 and 3A26 7 3A25 a Processing Description 3A25 processing is to compute the monthly average of rain parameter in lon lat 5 x 5 and 0 5 x 0 5 region using 1C21 2A21 2A23 and 2A25 The representative outputs are monthly average of rain rate mm h in lon lat 5 5 region at 5 layers altitude 2 km 4km 6km 10km and 15km and at path average and monthly average rain rate mm h in lon lat 0 5 x 0 5 region at 3 layers 2 km 4 km and 6 km and path average Additionally probability of rain parameters average standard deviation histograms and correlation coefficients of rain parameters are output b Input Data of 3A25 Processing For 3A25 processing the input data are read from 1C21 2A21 2A23 and 2A25
120. an be thought of as a single optical pulse due to lightning it is possible that multiple pulses occurring within the 2 ms integration window may contribute to an event Therefore we purposely did not use pulse or stroke or other similar name to describe the basic unit of data from the LIS Note an event may sometimes not be due to lightning at all It may be produced by noise in the analog data stream exceeding the background threshold In that case the event is a false alarm c Group Because a single pixel will almost never correspond to the exact cloud illumination area a lightning discharge will often illuminate more than one pixel during a single integration time The result is two or more adjacent events at the same time frame When these multiple events are adjacent to each other a side or corner of the events touching they will be placed in a single group The formal definition of a group is one or more simultaneous events 1 events that occur in the same time integration frame that register in adjacent neighboring or diagonal pixels in the focal plane array A group may consist of only one event or include many events The location data for a group will be calculated in earth based latitude longitude coordinates This is done to provide consistent representation in the group flash area processing and because the ultimate goal of the analysis to locate lightning with respect to the earth s surface A group is ide
121. an surface energy budget as well as climate studies which require higher accuracy TOA fluxes than provided by the ERBE like products process circles and ATBD subsystems 1 4 9 and 10 ATMOSPHERE Products which use cloud imager derived cloud physical properties NCEP National Centers for Environmental Prediction or EOS DAO Data Assimilation Office temperature and moisture fields ozone and aerosol data CERES observed surface properties and a broadband radiative transfer model to compute estimates of SW and LW radiative fluxes up and down at the surface at levels within the atmosphere and at the TOA By adjusting the most uncertain surface and cloud properties the calculations are constrained to agree with the CERES TOA measured fluxes thereby producing an internally consistent data set of radiative fluxes and cloud properties These products are designed for studies of energy balance within the atmosphere as well as climate studies which require consistent cloud TOA and surface radiation data sets Data volume is much larger than ERBE like or Surface products process circles and ATBD sub systems 1 4 5 6 7 and 8 TRMM DATA USERSHANDBOOK
122. and highest DID value in 5 km x 5 km box and 11 km x 11 km box is detected The range bin number corresponding to the mean height of DID in 5 km x 5 km box is also detected Additionally the range bin number corresponding to the bottom of range which is not influenced by main lobe clutter is detected and the range bin number corresponding to the surface of earth ellipsoid model is also detected Where surface range bin number detection is based on the algorithm of Dr Kozu of Shimane University and rejection of surface main lobe clutter is based on the algorithm of Dr Awaka of Hokkaido Tokai University f Calculation of minimum echo Rain no rain determination is carried out for received power level with regards to the system noise level and the threshold value defined in the header section and a flag is set up The position of precipitation layer rain height is also calculated based on the result of rain no rain determination The result of rain no rain determination is a six step flag which indicates reliability of precipitation echo and for each angle 0 Norain Echoes are very weak 10 Rain possible but may be noise Some weak echoes above noise exist in clutter free ranges 20 Rain certain Some strong echoes above noise exist in clutter free ranges 11 Rain possible but may be noise or surface clutter Some weak echoes exist in possibly cluttered ranges 12 Rain possible but may be clutter Some strong echoes exis
123. angle bins in the radar scan Rain Flag Rain no rain flag rain 1 no rain 0 The rain possible category rainFlag from 1B21 is included in the no rain category and only the rain certain category 1 considered rain Incidence Angle deg Incidence angle wrt nadir in degrees pitch roll correction is incAngle included 4 16 TRMM DATA USERSHANDBOOK PIA dB pathAtten Reliability Flag reliabFlag Reliability coefficient reliabcoefficient Estimated 2 way path attenuation The amount of the total rainfall attenuation is called PIA Amount of Path Integration Attenuation reliability Flag for the PIA estimate 10000 iv 1000 iw 100 ix 10 iy iz iv Rain no rain indicator 1 no rain along path 2 rain along path iw Indicator of the reliability of the PIA estimate 1 PIA estimate is reliable There is reliability 2 PIA estimate is marginally reliable Reliability boundary 3 PIA estimate is unreliable Reliability none 4 Because the S N is low the value of PIA is thought to be a low boundary value 9 no rain case ix Type of surface reference used 1 spatial surface reference is used to estimate PIA 2 temporal surface reference is used to estimate PIA 3 neither exists 1 e insufficient of data points 4 unknown background type 5 case amp low S N ratio do not update temporal or spatial surface references 6 global reference d
124. as output of 5 x 5 grid Nadir direction BB Ht statistics bbNadirHtMean1 Devl Nadir direction BB Width statistics bbNadirWidthMeanl Devl Nadir direction BB Zmax statistics bbNadirZmaxMeanl Dev1 lt Others gt unitless Mean and standard deviation of bright band heights from nadir direction Mean and standard deviation of bright band width from nadir direction Mean and standard deviation of bright band maximum Z from nadir direction These parameters are output for only 5 x 5 grid xi Q xiMean Dev NUBF Correction Factor nubfCorFacMean Dev c Histograms Mean and standard deviation of which is calculated in 2A25 processing Mean and standard deviation of Non Uniform Beam Filling NUBF correction factor which is calculated in 2A25 processing Histograms are simple count which is classified by using 31 designed threshold value and calculated for only 5 x 5 grid Rain Rate rainH Stratiform Rain Rate stratRainH Convective Rain Rate convRainH Near surface Rain Rate surfRainH Near Surface Stratiform Rain Rate surfRainStratH Near Surface Convective Rain Rate surfRainConvH Surface Rain Rate e surfRainH Surface Stratiform Rain Rate e surfRainStratH Surface Convective Rain Rate e surfRainConvH Histograms of rain rate each layer path average unconditioned on rain type Histograms of rain rate each layer path
125. as the TMI resolution and will be provided by the TMI team Climatological freezing height information The spatial resolution will be 5x5 and will be provided by the TMI team d Intermediate data Rain rate Brightness temperature histograms e Output data As 3A11 output the following data is calculated in lon lat 5 x 5 region grid These grids cover the area of 40 N 40 S x 180 180 W and the number of grid is 16 x 72 The land pixels are filled by 9999 Monthly Rainfall mm The Monthly Rainfall is the surface rainfall over oceans in 5 x 5 mothRain grids Number of Samples The Number of Samples is that are over oceans in 5 x 5 grids for noOfSamples one month Chi Square Fit The Chi Square Fit indicates how well the histogram of brightness chiSqFit temperatures fits the lognormal distribution function in 5 x 5 grid for one month Freezing Level km The Freezing Level is the estimated height of 0 C isotherm over freezLevel oceans in 5 x 5 grids for one month T O K The T 0 is the mean of non raining brightness temperatures over TO oceans in 5 x 5 grids for one month 0 mm h The r 0 is the logarithmic mean rain rate over oceans in 5 x 5 70 grids for one month Sigma r mm h The Sigma r is the standard deviation of logarithmic rain rates over sigmaR oceans in 5 x 5 grids for one month Probability of Rain The Probability of Rain is that are ov
126. ased satellite data Data Access Grid TKreadGrid TK writeGrid These routines read and write data for Level 3 grid based satellite data products and Level 2 and 3 GV products Data Access L1 GV TKgetNvos TKgetNsensor TKgetNparam TKgetNcell TKgetNray TKgetNsweep TKsetL1GVtemplate TKreadLIGV TKwriteLIGV TKreadLiGVparm TKreadL1GVdate TKreadLIGVbyVosNum TKfreeL1GV These routines access L1 GV data products The TKgetNxxx routines provide information about the granule TKsetL1GVtemplate creates a template for an output data product and TKreadL1GV and TKwriteL1GV read and write the L1 GV data TKreadL1GVparm will read a VOS with the specified parameter TKreadL1GV date will read all of the start and stop times of the VOSs in a granule TKreadL1GVbyVosNum will read a VOS with a user specified VOS number and TKfreeL1GV will free the memory associated with and user allocated VOS structure Metadata Access TKreadMetadataChar TK writeMetadataChar TKreadMetadataFloat TKwriteMetadataFloat TKreadMetadatalInt TK writeMetadatalInt There is a separate metadata routine for Character Floating Point and Integer data types The TKreadMetadataTYPE routines read a single metadata element into a typed variable The TKwriteMetadataTYPE routine writes a single metadata element to a file Since the metadata is stored internally as characters these routines translate from or to the appropriate type Header Access TKreadHeader T
127. ata It is not used in Version 6 7 Reference data by hybrid method 9 no rain case iy Information about surface detection 1 surface tracker locked central angle bin 2 surface tracker unlocked central angle bin 3 peak surface return at normally sampled gate outside central swath 4 peak surface return at normally sampled gate outside central swath iz Background type 0 ocean 1 land 2 coast 3 unknown or of a category other than those above or mixed type reliability Factor for the PIA estimate and it is given by reliabFactor PIA std dev reference value where is the 2 way path integrated attenuation dB and std dev reference value is the standard deviation as calculated from the no rain sigma zero values Both quantities are in dB The parameter iw in Reliable Flag is determined from this Factor F and the S N ratio SNR dB of the surface return in dB F gt 3 and SNR gt 3 gt W 1 3 gt F gt 1 and SNR gt 3 gt W 2 1 gt F and SNR gt 3 or 3 gt and 3 gt SNR gt W 3 F gt 3 and 3 gt SNR gt W 4 In 2A21 product moreover the same information as 1B21 is recorded about Meta data Scan time Geolocation Scan status and Navigation 4 17 Section4 OUTLINE OF THE TRMM PRODUCTS e Relationship with Other Algorithms The output of 2A21 is used for 2A25 3A25 and 3A26 5 2A23 Processing a Processing Description 2A23 processi
128. ation Valves 4 Roll Roll Thrusters 4 E T P Yaw Pitch d a di Delta V Thrusters 8 Pitch Pitch Figure 2 1 7 Reaction Control Subsystem Block Diagram 2 1 8 Deployables DEP The TRMM DEP consists of a High Gain Antenna Deployment and Pointing System HGAD PS the Solar Array Deployment and Drive System SADDS and a Gimbal and Solar Array Control Electronics GSACE box The High Gain Antenna HGA will be utilized for normal telemetry communications provides a two axis Pointing System PS for tracking and a High Gain Antenna Deployment System HGADS to deploy and support the HGA and PS The SADDS consists of two two panel Solar Array SA wings and two Solar Array Drive Assemblies SADA The GSACE controls the position of both the HGA pointing system and the SA rotary actuators in the SADA 2 8 TRMM DATA USERSHANDBOOK 2 1 9 Structure Subsystem STR The STR is categorized to two kinds of structure they are the main structure and the secondary structure The main structure is under load by stress by bending shearing and twist of satellite whole during launch land transportation and handling on ground The secondary structure is not under load by stress of satellite whole The STR 1 constructed from the following elements LBS Lower Bus Structure Element Name Quantity Radial 9 Interface Beam Central Cylinder Honeycomb Equipment Panel Upper Dec
129. average for stratiform rain Histograms of rain rate each layer path average for convective rain Histograms of near surface rain rate conditioned on rain certain only but unconditioned on rain type Same as the above but for stratiform rain Same as the above but for convective rain Histograms of estimated surface rain rate conditioned on rain certain only Same as the above but for stratiform rain Same as the above but for convective rain 4 30 TRMM DATA USERSHANDBOOK Shallow Rain Rate shallowRainMeanH Shallow Isolated Rain Rate shallowIsoRainH Un corrected rain attenuation Z Zm zmH Zm Stratiform Rain Rate stratZmH Zm Convective Rain Rate convZmH Corrected Z Z4 2 Stratiform Rain Rate stratZtH Z Convective Rain Rate convZtH Maximum Z Zax bbZmaxH SRT PIA piaSrtH SRT PIA Subset piaSrtssH HB PIA piaHbH HB PIA Subset piaHbssH 0 Order PIA 0 0 PIA Subset pia0ssH 2A25 PIA pia2a25H 2 25 PIA Subset pia2a25ssH Height of Bright Band BBHH Height of Storm Top stronHH Height of Storm Top stratiform rain stratStormHH Histograms of shallow rain Histograms of shallow rain isolated Histograms of radar reflectivity factor including rain attenuation each layer path average unconditioned on rain type Histograms of radar reflectivity fa
130. aves of two frequencies f1 13 796 GHz f2 13 802 GHZ every 360 23 which is a transmission pulse repetition interval PRI to each single beam direction in 32 pulses with a pulse width each of approximately 1 6 usec from an orbit with an altitude of 350 km It also measures the received power strength of the returned radio waves radar echo where transmitted pulse waves return after being scattered by raindrops and the ground surface For each transmitted pulse received power of the radar echo to an altitude of 20 km from the ground surface are sampled approximately every 250 m in terms of a range in the beam direction Sixty four 32 pulses x 2 frequencies received power sampling data for the same distance same range in a beam direction are averaged and transmitted to the ground Sixty four data made up from 32 pulses of two frequencies 15 statistically independent sample data and taking their average ensures the necessary observation precision S N The method of using two transmission frequencies to ensure independent sample numbers is called two frequency agility method The precipitation radar scans once every 0 6 seconds in the direction which is perpendicular cross track direction to the direction in which the satellite is travelling along track direction There are 49 beams observation angle bins with a beam every 0 71 degrees within the range of 17 degrees with the center at nadir Each scan carries out observation to 4
131. avily on the solar cycle There are four mission phases planned for TRMM mission operation and each mission phase has its inherent success standard and focus These phases are described in Figure 2 4 1 are as follows a Pre Launch Planning and Testing b Launch and In Orbit Checkout c Normal Mission Operations d End of Life Ocean Disposal By controlled reentry 1 Pre Launch Planning and Testing Phase The major activities of the pre launch planning and testing phase are installation of ground parts testing and flight operations plan This phase includes final inspection checkout and launch site operations 2 Launch and In Orbit Checkout Phase The launch and in orbit checkout phase starts with the launch and requires approximately 60 days The major activities of this phase are launching of TRMM orbit injection stabilization satellite checkout orbital descent to mission altitude turning the instruments on and calibration 3 Normal Mission Operations Phase The normal mission operations phase is the principal mission operations phase and takes at least three years Science data is collected during this period The phase consists of two steps such as the normal operation phase which is the mission design life of 3 years and 2 months and the post operation phase after that The mission operations phase started two months after launch January 31 1998 and then finely completed the normal operation phase January 31 2001
132. ba laptop computer 1510 orless 1760 orless 600 or less 920 orless 700 orless Maximum dimension of expansion Coating color NDS Z 8201C Color number 1802 white N9 Weight 110kg or less Figure 3 2 5 Appearance of Precipitation Radar Calibrator 39 Section3 OUTLINE OF THE GROUND SYSTEMS 3 3 Earth Observation Data and Information System The Earth Observation Data and Information System EOIS Data Distribution and Management System DDMS is a user front end system that offers Earth Observation Satellite Data Catalogue Information Service as well as related products to help you to utilize the earth observation satellite data This system manages various information necessary to select the earth observation data by using a database and distributes it online as well as provides the standard processed data through a variety of media and formats It has been installed at JAXA EOC The Earth Observation Data and Information System EOIS Data Distribution and Management System DDMS Overview is shown in Figure 3 3 1 Earth Observation Centerf EOC OnLine Inforrretion System Foreign organization INASA Mision Operation Data Distribution lanagerrent Subsystem j Subsystem Network Management Subsystem Receiving and Recording Catalogue data Distribution Subsystem em Browse data Distribution em
133. ber of PIA that are calculated from 2A25 by using HB Hitschfeld Bordan at five incidence angles 0 5 10 15 and mean of 49 angle bins Same as the above but for subset Subset is when w equals 1 or 2 for Reliability Flag in 2A21 and 8th bit equals 1 for method in 2A25 Number of PIA to integrate using k z relations from Zm that are not correcting rain attenuation at five incidence angles 0 5 10 15 and mean of 49 angle bins Same as the above but for subset Subset is when w equals 1 or 2 for Reliability Flag in 2A21 and 8th bit equals 1 for method in 2A25 Number of PIA Standard output of 2A25 that are calculated by using hybrid method of SRT and HB at five incidence angles 0 5 10 15 and mean of 49 angle bins Same as the above but for subset Subset is when w equals 1 or 2 for Reliability Flag in 2A21 and 8th bit equals 1 for method in 2A25 Number of bright band nadir direction pixel counts The following parameters are calculated for only 5 x 5 grid only when all four SRT HB Oth order and Standard output of 2A25 PIAs exist and are reliable or marginal PIA Correlation Coefficients Pixel piaCCoefPix Number for correlation coefficients of PIA that are calculated by using HB SRT Oth order and Standard output of 2A25 For example the following probabilities can be calculated by using combination of the above parameters 4 26 TRMM DATA USERSHANDBOOK Pr
134. block diagram of PR are described below 1 Elements The precipitation radar is made up of the subsystems and the components shown in Table 2 6 1 Table 2 6 1 Subsystem and Component Antenna subsystem Transmit Receive subsystem He phase shifter amplifier Band pass filter BPF Redundant configuration Same as the one used in FCIF RF power supply RF PS Redundant configuration System control data Redundant configuration Signal processing processing assembly 1 supplied from FCIF Structure subsystem SR Ist PO Thermal control subsystem B Integration subsystem d ist Receive drive RDA 2 Redundant configuration 2 2 2 2 2 2 32 TRMM DATA USERSHANDBOOK 2 Appearance The appearance of the precipitation radar is shown in Figure 2 6 1 3 Function Block Diagram The functional block diagram of the precipitation radar is shown in Figure 2 6 2 eme UE n 4 i gt eS 9300 Op mim Figure 2 6 1 Appearance of PR Section2 OUTLINE OF THE TRMM SATELLITE iouiquo J9pfpAPQ 4291991 cy Jloutquoj JOopIAT 4242198 JOYS ased Lx pod indinganduy Ajddng Jy x 130g
135. bsystem Figure 2 6 5 The PR Subsystems and Components 2 6 5 1 Antenna Subsystem The antenna subsystem is interfaced between the transmit receive subsystem and the RF signal transmission waveguide of 128 systems It emits transmission signals supplied from the transmit receive subsystem into space and supplies the received waves reflected from raindrops and others to the transmit receive subsystem 1 Structure The precipitation radar employs an active phased array antenna system The phased array system is a system in which the beam direction is controlled by electronically shifting the phase using 2 42 TRMM DATA USERSHANDBOOK phase shifters connected to each of the numerous antenna elements arranged on the antenna aperture face The antenna subsystem is an array antenna where 128 waveguide slot antennas are arrayed in a direction perpendicular to the flight direction of the satellite 2 Functions The main functions of the antenna subsystem are 1 Emits radar transmission signals to space and receives the radar reflected echo 2 In accordance with the amplitude phase distribution of each subsystems formed by the transmit receive subsystem it scans the antenna beam orientation within a plane that is perpendicular to the direction in which the TRMM observatory is travelling 3 Performance 1 Antenna formation Non resonating waveguide slot array antenna 2 Number of antenna elements 128 3 Electric apertur
136. by linear interpolation Attenuation parameter beta of k Z relationship k aZeP Beta is constant for all ranges in each angle bin Range bin numbers of the nodal points at which the attenuation parameters alpha and beta are given In no rain angle bins this parameter is set to 0 Z factor after attenuation correction Ze If the input radar reflectivity factor Zm is below the noise level or if the estimate is below 0 dB this parameter is set to 0 0 A value of 88 88dB stored as 8888 is a ground clutter flag Final correction factor of alpha by HB method Hitschfeld Bordan and SRT method Surface Reference Technique Final correction factor of alpha by SRT method Surface Reference Technique Error estimate of rain near the surface Error estimate of correct Z Factor near the surface Rainfall estimate at the detected surface bin Height of freezing level estimated from the climatological surface temperature data sst hou data 7 0 Estimated height of freezing level 5555 When error occurred in the estimation of freezing height 9999 Data missing Method rain model used in the retrieval of vertical profiles of Ze factor and rain Near surface rain rate estimate Near surface is defined as the lowest point in the clutter free ranges in almost all cases However if Zm at this point is below the noise level and if the estimated attenuation down to this point is larger than t
137. by wired OR in the precipitation radar system harness Because it is the power supply for the transmit receive subsystem abbreviation is differentiated and is RF PS b Function 1 Inputs the external bus power source and supplies power necessary for each assembly 2 Itcan activate stop instruments by command signals and monitor the operation states of the instruments by telemetry signals 3 Stops the operation of instruments using emergency off signal 4 Furthermore during reclosing of the power source it is activated by a command Redundant system 15 formed by carrying out wired OR to the output of two RF PSs 5 Itis controlled so that normally only one RF PS is in operation with the other stopped 2 6 5 3 Signal Processing Subsystem The signal processing subsystem carries out the control of the radar system collection processing of radar data and telemetry command interface between the satellite and 0 on 1 System Control Data Processing Assembly SCDP The system control data processing assembly supplies the control signals to SSPA LNA and divider combiner 2 of transmit receive subsystem switches transmission reception and controls antenna beam scan etc It also supplies the satellite side with the video signals supplied from frequency converter IF assembly after carrying out A D conversion and average processing Furthermore it also supplies the satellite side with the collected telemetry such as the temperatur
138. c ae E waisksang pod Figure 2 6 2 PR Functional Block Diagram TRMM DATA USERSHANDBOOK 2 6 2 Functions The major functions of the precipitation radar are 1 Major Functions Measurement conceptual diagram is shown in Figure 2 6 3 1 2 3 4 5 7 8 Transmits short sinusoidal waves in the direction of the earth and receives the radar echo scattered by raindrops and the like from a range necessary to find out the vertical distribution of rainfall A beam is scanned within a plane that is vertical to the direction in which TRMM observatory is traveling so as to find out the three dimensional structure of rainfall Averages the total of 64 pulses received in 32 pulse lots from two frequencies Two frequency agility Measures quantitatively the radar received power the radar reflectivity factor Z factor and the normalized scattering cross section of earth surface o internal calibration function system noise level measuring function Measures the precipitation radar calibration that uses a calibrator positioned on the ground and the antenna pattern Carries out thermal control to the precipitation radar to ensure a normal operation and performance Command function necessary for setting the operation mode of the precipitation radar and switching between the primary redundant system etc and the telemetry function for the condition monitor To carry out interface wi
139. cessing 3B42 including intermediate product of uuclipped TMI 3B31 3A46 SSM I estimate and 3A45 Rain gauge are input c Output Data of 3B42 Processing The outputs of 3B42processing are listed in below Precipitation mm This 1 the adjusted merged IR precipitation estimate at each 0 25 precipitate x 0 25 grid Relative Error This is the adjusted merged IR precipitation error at each 0 25 x relError 0 25 grid d Relationship with Other Algorithms The output of 3B42 is used for 3B43 4 3B43 Processing a Objective The objective of 3B43 is to provide a best precipitation estimate on each 0 25 x 0 25 grid within the TRMM region from all global data sources shown in below TMI Estimate This is the monthly accumulated unclipped TMI precipitation estimate which is given as intermediate product from 3B42 processing TRMM DATA USERSHANDBOOK SSM I Estimate 3446 This is the monthly accumulated precipitation and estimated by using observation data from Special Sensor Microwave Imager SSM I Adjusted Merged IR Estimate This 1 output of 3B42 processing Rain Gauge Analysis 3A45 This is the monthly accumulated rain gauge data from Climate Assessment and Monitoring System CAMS Global Precipitation Climatology Center GPCC input data sources are on the calendar month temporal resolution with the exception of the adjusted merged IR data which is on the pentad 5 day re
140. change Moreover concerning about function of PR modifications of data processing algorithm are required due to mismatch of transmit to receive angle However it is considered that change of these parameters does not have so big influence on Science research 2 7 4 Mismatch of Transmit to Receive Angle Since PR applies the fixed transmit receive timing orbit altitude change of around 50km leads to delay of the received electric wave for Pulse Repetition Frequency That is a received electric wave enters the receiving gate for the next pulse of original one If direction of the next pulse is same as original one it is basically no problem However in the case of a different direction a mismatch occurs at the angle of transmission and reception This phenomenon 1 found in one pulse of the 32 pulses The routine for removing this effect is added to PR 1B21 processing algorithm The detailed contents and problems are described in the section 4 1 1 2 2 7 5 Influence on Other Sensors The influence by orbit boost to TMI VIRS and LIS is not so serious as PR It is considered that science research is hardly affected by orbit boost although resolution and swath width increases about 1 15 times TRMM DATA USERSHANDBOOK 2 7 6 Attitude Control System Before orbit boost the ESA was used for attitude control i e roll and pitch controlling However since ESA operates normally within altitude range from 335 to 390km as s
141. ctor including rain attenuation each layer path average for stratiform rain Histograms of radar reflectivity factor including rain attenuation each layer path average for convective rain Histograms of correct radar reflectivity factor each layer path average unconditioned on rain type Histograms of correct radar reflectivity factor each layer path average for stratiform rain Histograms of correct radar reflectivity factor each layer path average for convective rain Histograms of maximum Zi in bright band conditioned on presence of bright band Histograms of PIA which is calculated by using SRT Surface Reference Technique at five incidence angles 0 5 10 15 and mean of 49 angle bins Same as the above but for subset Histograms of PIA which is calculated by using HB Hitschfeld Bordan at five incidence angles 0 5 10 15 and mean of 49 angle bins Same as the above but for subset Histograms of PIA which is calculated by using k Z relation from Zm which is not correcting rain attenuation at five incidence angles 0 5 10 15 and mean of 49 angle bins Same as the above but for subset Histograms of PIA which is calculated by using hybrid method of SRT and HB at five incidence angles 0 5 10 15 and mean of 49 angle bins Same as the above but for subset Histogram of bright band height Histogram of storm top height uncond
142. cts and a flag set to indicate that a corrected UTCF was used When a corrected UTCF is applied the UTC Scan Times will be different between 1 Level 1A and 2 Level 1B and higher levels although the spacecraft clock Scan Times will be the same in Level 1A and Level 1B and higher levels Another flag in Level 1B and higher levels shows whether a leap second occurred in the granule Times are expressed in five formats 1 UTC times in Core or PS metadata or a Level 1A header are written in three words Date Time and Milliseconds For the Begin and End Times in Core metadata milliseconds are omitted Date 15 a 10 character string with the following characters YYYY MM DD where YYYY year MM month number DD day of month and is a literal Time is an 8 character string with the following characters HH MM SS where HH hour MM minute SS second and 66 99 7 is a literal Milliseconds is a 3 character string with the following characters MMM where MMM number of milliseconds later than the last whole second 2 In 1B11 and 2A12 UTC time is stored in separate words for year month day of month hour minute and second 4 76 TRMM DATA USERSHANDBOOK 3 UTC Scan Time in the body of the data 1 in seconds of the day The UTC date and time in the metadata can be combined with the Scan Time to get a complete date and time for every scan 4 Spacecraft clock time and U
143. d 7 0 Height of bright band 111 No bright band 8888 No rain 9999 Data missing Intensity of Z factor in bright band gt 0 Bright band intensity 1111 No bright band 8888 No rain 9999 Data missing 419 Section4 OUTLINE OF THE TRMM PRODUCTS Height of Freezing Level m Height of freezing level estimated from the climatological surface freezH temperature data sst hou data 7 0 Estimated height of freezing level 5555 When error occurred in the estimation of freezing height 9999 Data missing Height of Storm Top m Height of storm top with high level of confidence stormH 7 0 Bright band intensity 1111 No storm height with high level of confidence 8888 No rain 9999 Data missing Boundary of Bright Band Range bin number of the boundary of the bright band BBboundary 70 range bin number 1 for upper boundary of BB 2 for lower boundary of BB 1111 No bright band 8888 No rain Width of Bright Band m Width of the bright band in meters BBwidth 70 width of the bright band 111 No bright band 8888 No rain Status of Bright Band Quality of bright band detection BBstatus 1 poor 2 fair 3 good In 2A23 product moreover the same information as 1B21 is recorded about Meta data Scan time Geolocation Scan status and Navigation d Relationship with Other Algorithms The output of 2A23 is used for 2A25 3A2
144. d global climate the measurement of global rainfall is extremely difficult because of its high spatial and temporal variabilities In particular relatively few rainfall data has accumulated in the tropics and over oceans Satellite remote sensing is probably the only way to provide reliable rainfall data on a global scale TRMM is the first space mission dedicated to measuring tropical and subtropical rainfall through microwave and visible infrared sensors including the first space borne rain radar The ocean and the land absorb more than half the solar energy incident to the Earth This absorbed energy causes the evaporation of the water from Earth surface The water vapor condenses aloft and then falls as rainfall The latent heat release in this process is the major energy source in the tropical atmosphere and the driving force of global circulation Figure 1 3 1 shows examples of relationship between sea surface temperature and atmospheric circulation in the tropics for the cases of normal and anomalous El Ni o conditions Warm water distributed in the western pacific during the normal condition while warm water region shifted to the east in the anomalous condition Atmospheric circulation changes with the location of warm water region The TRMM measurements are expected to provide a dataset that will be extremely valuable for understanding and for predicting global climate change and weather anomalies such as related to t
145. d into two types core metadata EOSDIS Core System ECS metadata and product specific metadata Core metadata are common to most Earth Observing System EOS data products Product specific metadata include the specific information of each product Several parameters describing the PR electronic performance Transmitter gain correction factor Receiver gain correction factor LOGAMP Input Output characteristics The Ray Header contains information that is constant in the granule such as the parameters used in the radar equation the parameters in the minimum echo test and the sample start range bin number These parameters are provided for each angle bin Scan Time is the center time of 1 scan the time at center of the nadir beam transmitted pulse It is expressed as the UTC seconds of the day The exact relationship between Scan Time and the time of each IFOV is described in section 4 2 3 7 The earth location of the beam center point per angle bins at the altitude of the earth ellipsoid If the earth location cannot be calculated the geolocation output becomes 9999 9 The status of each scan that is quality flags of spacecraft and instrument are stored This is the output of NASA s Geolocation Toolkit It consitsts of the information of satellite location velocity attitude and so on for each scan Power is recorded for each scan and consists of the calibrated PR transmitter power dBm 10
146. d to power values dBm and radar reflectivity factor Zm with physical significance in contrast to telemetry data which is count values This data becomes the basis for all analyses with precipitation characteristics actually only becoming clearer after data has been analyzed with Level 2 processing Level 2 processing results 2A21 2A23 2A25 give the precipitation characteristics of each IFOV and these are the interest values for scientific purposes They are useful when information on rainfall such as 3 D structure of rain rate types of rain height of rainfall and so on are desired Level 3 processing results 3A25 3A26 provide monthly statistics of rain distribution and so on 4 34 TRMM DATA USERSHANDBOOK and they are useful when statistical values are desired 4 1 2 TMI TMI Data Products and outline of their algorithms are explained below The structure of each product is described in the later section 4 2 4 2 4 1 2 1 Product Definition TMI products are shown in Table 4 1 2 Table 4 1 2 TMI Products Description 1 TMI Brightness Temperatures to which radiometric and geometric correction is carried out 2 12 TMI Rain Profile which is given for each pixel at vertical 14 layers and consists of several physical parameters such as cloud water precipitation water cloud ice precipitation ice and latent heating In this product moreover intensity of surface rain and convective rain a
147. dB b Radar receive power within 0 9 dBf c Radar transmit power within 0 4 dB 20 Surface echo strength Less or equal to 0 5 mm h rainfall echo strength within the by the antenna side observation range provided in 13 Antenna side lobes shall be lobes and the cross 20 dB or less than the noise level and cross polarization grating polarization grating lobes shall be 5 dB or less than the noise level in the system noise lobes detection window provided in 14 Antenna input noise temperature shall be 120 K 21 Range side lobes for receive pulse 25 dB or less 22 Reception filter loss 1 5 dB or less 23 Antenna gain 47 4 dB or more At antenna subsystem input output port 24 Antenna beam half 0 71 0 02 degrees at nadir width 0 74 0 03 degrees at a scan angle of 17 degrees 25 Antenna side lobes peak value 27 dB or less integration value at the same range 64 dB or less 0 lt 0 lt 40 26 Inclination angle of antenna beam 4 0 1 degrees to the direction of feeding point 27 Maximum antenna scan angle 17 degrees or more in the cross track direction 28 Grating lobes Not generated when the antenna is scanned within the scan angle range provided in 27 29 Cross polarization grating lobes 15 dB 30 Transmit receive beam orientation conformity within 0 07 31 Beam orientation precision The error of the antenna beam orientation uncertainty to the radar alignment reference is within 0 2
148. dar on the ground in that its radar echo contains a strong scattering echo from the ground surface or the sea 2 41 Section2 OUTLINE OF THE TRMM SATELLITE surface The rainfall attenuation from this strong echo can be used to improve the accuracy of the estimated rainfall intensity The observation data of this precipitation radar is sampled for each range resolution 250 m determined by the radar pulse width However ground surface echo near the vertical incidence is extremely strong and hence it is difficult to seek accurate echo levels for each 250 m sample Therefore to reduce the observation error data 1 obtained at 125 m sample intervals This is called over sample and it tracks ground surface echo and obtains data near that region in a minute detail This processing is carried out by the data processing algorithm installed in the system control data processing assembly of this precipitation radar 2 6 5 Explanation of the Components The precipitation radar is made up of the subsystems and components as shown in Figure 2 6 5 PR Antenna subsystem Transmit Power amplifier Receive subsystem TRS Low noise amplifier Divider Combinerl Divider Combiner2 Transmit drive amplifier Receive drive amplifier Band pass filter RF power supply Signal proceprocessing System control data processing subsystem SP Frequency converter IF section PLO Unit Structual subsystem Thermal control subsystem Integration su
149. ded by EOIS sss 5 3 Table 5 2 2 TRMM Image Catalog 5 3 Table 5 3 1 TRMM products provided by scene order nennen 5 4 Table 5 3 2 Items to be specified for Scene Order sessi 5 5 Table 5 3 3 Items to be specified for Standing Order sss 5 6 Table 5 3 4 List of TRMM Distribution 5 7 Table 5 3 5 Sample Data Provided Hoces rineto raini a n in a ansaa 5 8 Table 6 1 Main Events of TRMM Mission 6 2 TRMM DATA USERSHANDBOOK 1 INTRODUCTION TRMM Tropical Rainfall Measuring Mission was launched by the H II rocket from Tanegashima Space Center of the then NASDA National Space Development Agency of Japan From October 2003 on re organized as JAXA Japan Aerospace Exploration Agency at AM 6 27 JST November 28 1997 This satellite was developed as a joint project between Japan and US 15 the first space mission dedicated to measuring rainfall TRMM mainly observes rain structure rate and distribution in tropical and subtropical regions the data plays an important roll for understanding mechanisms of global climate change and monitoring environmental variation 1 1 Purpose This handbook provides necessary information to users to utilize TRMM data including information related to standard products and also introduces reference information such as TRMM spacecraft onboard instruments and ground syste
150. e code data stored in RAM will also be deleted 2 Frequency Converter IF Assembly FCIF a Structure Frequency converter IF section FCIF is one of the composition instruments of the signal processing subsystem of the precipitation radar and two of these makes up the redundant system FCIF is made up of Ku band transmit receive subsystem LOCAL system and IF band 60MHz band transmit receive subsystem control circuit and power source b Function 1 Generates 2 frequency pulses and supplies the transmit receive subsystem 2 Stops generation of either or both of the two frequency pulses by a command 3 Carries out frequency conversion IF amplification band limiting and logarithmic wave 2 47 Section2 OUTLINE OF THE TRMM SATELLITE detection of the radar transmission reception signals output from the transmit receive subsystem and output radar video signals to the system control data processing section 4 Possesses RF signal reflection loop so as to enable calibration of the receive input output characteristic on the ground Also calibration is controlled by the control signals This function is used with the internal calibration mode of the precipitation radar system 5 To monitor the output video voltage drift it carries out matched termination at the input port of the logarithm wave detector by control signals 6 Adjusts the reception gain by a command Varies to 5 steps in 3 dB step 7 Turns the FCIF
151. e power of ARC and receive transmit power of PR this mode will be used to determine calibration value such as receive coefficient or transmit coefficient These calibration coefficients will be incorporated in the PR Level 1 processing software Using value of this mode the concentration display of antenna pattern of along track cross track and PR received 2 36 TRMM DATA USERSHANDBOOK power will be performed To carry out these operations the external calibration mode is divided into the following two submodes depending on the scan method of the antenna beam e Limited Scan Mode A mode where seven beams 0 355 intervals centering around the specified observation angle bin are scanned This mode 1 a specific mode so that it can certainly receive a reference signal by closer pitch scan than the observation mode e Fixed Beam Mode A mode fixed to a specified scan angle bin No scanning c Internal Calibration Mode This mode is used to measure linearity and error of logarithmic inclination of the LOGAMP to convert received signal into video signal Where the received signal is the signal received by reflecting the RF Radio Frequency pulse using the reflected loop inside the PR the RF signal possesses 32 reference signals of 2 6 dB step width variable ATT and it will be measured in dynamic range User can specify which point of data is used for the processing The calculated difference value will be output as input outpu
152. e amount of heat energy which is emitted from the Earth and its atmosphere and observed by CERES on December 28 1997 The color scale ranges from cold to hot Blue indicates cold tops of cloud systems and red hotter regions on the Earth such as the deserts and tropical oceans The anomaly that an over voltage was loaded for the CERES instrument occurred around August 1998 9 months after launch analysis of the cause and some counter plans have been intermittently done and the science data acquisition has been limited The CERES operation was terminated at May 2001 615 Section6 TRMM OPERATION STATUS RESULTS and FUTURE PLAN Processed 1998 01 16 Measurement Level Instantaneous 00 00 23 59 lt 2d pa Ep 65 115 165 215 265 315 Watts Meter Fig 2 Longwave TOA Flux from CERES ERBE like Processing TRMM December 28 1997 ES 8 Figure 6 4 5 Long wave TOA Flux from CERES ERBE like Processing 5 Total Number of Lightning Flashes Figure 6 4 6 shows the total number of lightning flashes which was observed by LIS in January 1998 Lightning was concentrated over the inland in the Southern Hemisphere the African continent the Australia continent and the South America continent in January when it was midsummer in the Southern Hemisphere Lightning was not observed over the ocean in the Southern Hemisphere even though it was also midsummer Lightning over the ocean was observed like a line
153. e diameter 2 mx 2 1 m 4 Center frequency 13 796 GHz f1 and 13 802 GHz f2 two cycle frequency agility 5 Polarized wave Horizontally polarized wave 6 Bandwidth 10 MHz or more 7 Efficiency 95 or more 8 Waveguide loss 0 5 dB or less 9 VSWR 1 20r less Antenna element unit characteristic 10 Gain 47 4 dB or more At antenna subsystem input output port 11 Beam half width 0 71 0 02 degrees nadir 0 74 0 03 degrees at scan angle of 17 degrees 12 Side lobes Peak value 27 dB or less 13 Beam inclination angle 4 0 1 degrees to feeding point 14 Maximum scan angle 17 degrees or more in the cross track direction 15 Coordinate axes of the antenna subsystem Mechanical coordinate axis Xa Ya Za and electric coordinate axis Xe Ye Ze are used for the coordinate axes of the antenna subsystem These coordinate axes are shown in Figure 2 6 6 2 43 Section2 OUTLINE OF THE TRMM SATELLITE Precipitation radar antenna subsystem electric coordinate axis Antenna subsystem mechanical coordinate axis Z Za Ye Xe 4 degrees Xa Antenna Zm x Precipitation radar structure subsystem m Ym Precipitation radar mechanical coordinate axis Figure 2 6 6 Antenna Subsystem Coordinate Axes 2 6 5 2 Transmit Receive Subsystem The transmit receive subsystem amplifies the transmission signals supplied from the signal processing subsystem using the transmit drive amplif
154. e interpolation of solar absorption within the atmospheric column A key issue is to avoid biases caused by the systematic increase of albedo with solar zenith angle for times of observation between sunset and sunrise and the first daytime 4 54 TRMM DATA USERSHANDBOOK observation hour 9 Subsystem 9 Grid TOA and Surface Fluxes for Instantaneous Surface Product SURFACE Data Product This subsystem is essentially the same process as in subsystem 6 The major difference is that instead of gridding data to be used in the Atmosphere Data Products subsystems 5 6 7 and 8 this subsystem spatially grids the data to be used in the Surface Data Products subsystems 9 and 10 The spatial grid is the same 1 0 degree equal angle See the data flow diagram Figure 4 1 10 10 Subsystem 10 Monthly Regional TOA and Surface Radiation Budget SURFACE Data Product The time averaging for the Surface Data Product is produced by two methods The first method is the same as the ERBE method ERBE like product in subsystem 3 with the following exceptions Improved CERES models of solar zenith angle dependence of albedo Improved cloud imager scene identification subsystem 4 and improved CERES ADM s to provide more accurate instantaneous fluxes Simulation studies indicate that the monthly averaged fluxes will be a factor of 2 3 more accurate than the ERBE like fluxes The second method incorporates geostationary radiances similar to
155. e of each precipitation radar part and their operating states It also controls such 2 46 TRMM DATA USERSHANDBOOK things as on off of instruments and switching of the operation modes using the commands supplied from the satellite side a Structure System control data processing section SCDP is made up of two primary redundant system digital electronic circuits a portion is both analog and digital b Function Main functions of SCDP are 1 Processing of radar video signals and analog telemetry 2 Radar operation control 3 Data processing related to surface echo and system noise data processing section software 4 Generation of standard clock various types of timing signals and time signals 5 Interface control between S C 6 Interface between each subsystem 7 Health check function 8 Power on off control SCDP power source DC AC converter turns itself off after turning off FCIP and RF PS through command signals supplied from the CPU software approximately 4 seconds after CPU software receives the safe hold low power warning signal from S C Also it is turned on when the primary power source is re supplied When SH LP signal is not sent to PR and the primary power source is cutoff SCDP FCI and RF powers are cutoff but without hardware damage However because the power is cutoff during an operation science HK telemetry which was being transmitted to S C at that time will disappear and the phas
156. easibility study has shown HDF overhead to be less than 10 of the total file size for TSDIS products 4 72 TRMM DATA USERSHANDBOOK BCS Cure EE hrs des Dam Waher CGranule nf recan nscam Arruy 2 DUE Figure 4 2 5 Example Product Structure 4 2 3 2 File Contents In the description of the contents of each object within a file each object is defined in the following format Name Type of HDF structure Dimensions word size and type Description 4 2 3 3 Missing Data Missing satellite scans are filled with standard values denoting missing data Missing satellite scans also have the missing byte in Scan Status set to 1 Values less than or equal to 99 9999 9999 9999 9 9999 9 denote missing or invalid data for 1 byte integer 2 byte integer 4 byte integer 4 byte float and 8 byte float respectively Any exceptions to the use of these standard values are explicitly noted in the description of the object For the PR instrument scans whose mode is other than observation mode are filled with missing values If an entire orbit of satellite data is missing scan data is omitted and the metadata named Orbit Size has the value zero 4 73 Section4 OUTLINE OF THE TRMM PRODUCTS 4 2 3 4 Array Dimension Order In the definition of array dimensions e g npixel x nscan the first dimension npixel has the most rapidly varying index and the last dimension nsca
157. ecified multiple kinds or multiple days products of a specified sensor as a single dataset This service is available only to registered users Because the purpose of this data set order is to deliver large number of the products of planned processing to users at a time the ordered products cannot be selected by using this method TRMM DATA USERSHANDBOOK 3 Standing order Standing order is primarily acceptable for data that they will be acquired or generated in future When a product to meet the pre requested order is generated the product will be recorded on the distribution media and distributed to the requester Standing order is accepted for CERES and LIS in addition to the products in Table 5 3 1 Regarding CERES and LIS the products can be provided by dead copy of media provided from NASA including all levels of data 4 Order items To request TRMM data items in Table 5 3 2 and Table 5 3 3 are specified Example of order sheet is shown in Figure 5 3 1 Table 5 3 2 Items to be specified for Scene Order e Ne E Scene number Multi file group 0 Specify group number for multi file Ordering within group pecify ordering number within the group for multi file Product version Specify product version latest version in case of no selection E Essential item requires to be specified O Optional item to be specified Identifier for each orbit accumulated orbit number of the satellite 2
158. ecking RAMs and ROMs used in the System Control Data Processing SCDP component By electrical power turn on PR moves from Safety Mode to this mode LNA This mode is used to check whether each LNA is alive or not During this mode no science Analysis jobservation will occur Stand By This mode is for checking the phase code stored in the SCDP Also this mode shall be selected to temporarily stop the RF radiation During this mode the PR instrument is ON but is not initiating any RF transmissions Safety This mode will be used when the TRMM observatory 1 in any of the following modes of operation Launch Mode Initial Orbit Acquisition Mode Safe Hold Low Power Mode When Safe hold Low Power signal is received the PR instrument will be internally commanded to this mode prior to the autonomous removal of the NEB power supply During this mode the PR instrument is OFF with the exception of the survival heaters 15 Min 5 Min 15 Min 90 Yaw Calibration 90 Yaw Normal Ops Figure 2 5 3 Cross track Antenna Pattern Measurement Calibration Timeline 2 5 2 2 TMI The TMI instrument has a single operational mode and no commandable redundancy Accordingly command procedures are minimal and will focus on power control TMI essentially has two modes OFF and ON After initial power up it is intended that the TMI will remain powered at all times barring any specific anomalies 1 e Safehold Low Power TMI anomaly In addition
159. ed in 9 to 11 13 Observation range a During observation It is possible to observe surface echo by antenna main lobes from an altitude of 15 km Furthermore at a scan angle of 0 a mirror image of up to an altitude of 5 km is included 14 System noise level Measured within the range at which the radar echo can be ignored 15 Averaged individual sample number of a radar video signal 64 or more 16 Dynamic range Because both the surface echo level and the noise level are measured simultaneously at nadir at sea surface shall be 16 dB and the antenna input noise temperature shall be 120 K the linear section of the receiver integrated input output characteristic a characteristic where receive subsystem noise is assumed to be ignorable and includes logarithm detector and A D conversion to the sinusoidal pulse input has a margin of 5 dB or more above and and surface echo levels provided in this section 17 Linearity Within 0 6 dB in the linear section of 16 18 Range reference point determination precision 10 or less of range resolution 19 Measurement precision Observable echo height is ranged from 15 to 30 km due to satellite orbit and oblateness of the earth tis an assumed point where the distance from the precipitation radar is 326 924 km and it shall be range bin 1 2 39 Section2 OUTLINE OF THE TRMM SATELLITE a Equivalence Z factor and surface normalized radar cross section within 1
160. ed in the ACS packet Start finish time of the scene information is also converted into a format that is the same as the time code using UTCF and the leap seconds derived from the scene start time Based on this information the science data and HK data within the PR Level 0 data are sampled d Conversion to engineering value PR HK data RF PS voltage FCIF temperature panel temperature antenna temperature and IPSDU current and voltage within HK data are converted into engineering values Data converted into engineering values are output to HK data file e Limit check A limit check is carried out to the data already converted into engineering values and if they are outside the limits the operator is notified of limit abnormality generation Also abnormality monitoring items CPU RESET FLAG PHASE CODE ERROR FLAG RAM CHECK FLAGI RAM CHECK FLAG2 RAM CHECK FLAG3 RAM CHECK FLAG4 and T ROM CHECK FLAG are monitored for any abnormality and if an abnormality is discovered the operator 15 notified of abnormality generation f Scene editing If there is a wait file specified by the input parameter file it is combined with the head of a scene and output to a Level 1A file specified by the parameter file Scene divided science data and HK data from the same scene as well as the calibration file specified by the parameter file are also output to the Level 1A files specified by the parameter file Data less than a scene is output
161. ed on rain Mean 1 are mean and rainDev1 standard deviation of 5 x 5 Mean2 and Dev2 are mean and rainMean2 standard deviation of 0 5 x 0 5 rainDev2 Stratiform Rain Rate Same as the above but for stratiform rain stratRainMean1 Devl Mean2 Dev2 Convective Rain Rate Same as the above but for convective rain convRainMeanl Devl Mean2 Dev2 Near surface Rain Rate Mean and standard deviation of near surface rain rate surfRainMeanl Devl Mean2 Dev2 conditioned on rain certain only Stratiform Near surface Rain Rate Same as the above but for stratiform rain surfRainStratMeanl Devl Mean2 Dev2 Convective Near surface Rain Rate Same as the above but for convective rain surfRainConvtMeanl Devl Mean2 Dev2 4 27 Section4 OUTLINE OF THE TRMM PRODUCTS Surface Rain Rate e surfRainMeanl Devl Mean2 Dev2 Stratiform Surface Rain Rate e surfRainStratMeanl Devl Dev2 Mean2 Convective Surface Rain Rate e surfRainConvMeanl Devl Mean2 Dev2 Shallow Rain Rate shallowRainMean1 Dev1 Mean2 Dev2 Shallow Isolated Rain Rate shallowIsoRainMeanl Dev1 Mean2 Dev 2 Convective Rain Rate Epsilon epsilonConvMeanl Devl Mean2 Dev2 Stratiform Rain Rate Epsilon epsilonStratMeanl Devl Mean2 Dev2 Convective Rain Rate Epsilon0 Epsilon ConvMeanl Devl 2 Dev2 Stratiform Rain Rate Epsilon0 Epsilon StratMeanl Devil 2 Dev2 All r
162. em and the TSDIS processed data stored in EOIS are provided by a media 8 mm tape CD ROM DVD or DLT corresponding to user requests The format is only HDF for all products of TRMM TRMM PIs can order TRMM data and monitor the status of their order by online through EOIS 5 3 1 Ordering of TRMM Data Scene order and standing order are provided PIs normally use a standing order service In case to submit a spot request such as for emergent request PIs will use a scene order service On the other hand general users can use the scene order service basically However general users can use standing order service when they order PR 2A25 in the unit of 1 day 10 day or 1 month 1 Scene order Users will specify and order their requested product by a scene Scene order is accepted for only stored data in EOC Users can order not only full scene data of 1 path scene but also sub scene data of fixed region around Japan and lat long 10 deg gridded data Products to be ordered by the scene order are shown Table 5 3 1 Table 5 3 1 TRMM products provided by scene order Type of scene Products Full scene fixed region sub scene 1C21 2A25 ne are selectable Full scene sub scene are selectable Full scene only Fixed Region Sub scene Region over Japan which covers 80 to 160 degree East Longitude and 5 degree South to 35 degree North Latitude Sub scene Lat Long 10 degree gridded data 2 Dataset Order Users can order a sp
163. ented by the logical range bin number Two types of First Echo Height are estimated depending on whether the minimum echo flag 10 or 20 If the first echo is detected below the clutter free bottom the three types depend on whether the flag 11 12 or 13 The angle between the local zenith on the Earth ellipsoid and the beam center line The distance between the spacecraft and the center of the footprint of the beam on the Earth ellipsoid The land or ocean information from the DID 0 water ocean or inland water 1 land 2 coast not water nor land 3 water surface peak is not correctly detected because of high attenuation 4 land coast surface peak is not correctly detected because of high attenuation The topographic mean height m of all DID samples in a 5 x 5 km box Logical range bin number corresponding to height of earth ellipsoid model surface This is the bottom range bin number logical range bin number in clutter free range bins The range bin number corresponding to the mean height of all DID data samples available in a 5 x 5 km area that overlaps most with the footprint The range bin number corresponding to the highest value top of all DID data samples in a 5 x 5 km and 11 x 11 km box The range bin number corresponding to the lowest value bottom of all DID data samples in a 5 x 5 km and 11 x 11 km box The logical range bin number of starti
164. epsilon Pixel epsilonStratPix1 Pix2 Convective Rain epsilonO Pixel epsilon ConvPixl Pix2 Stratiform Rain epsilonO Pixel epsilon0StratPix1 Pix2 R Z Coefficient Pixel Pix1 Pix2 Convective Rain R Z Coefficient Pixel ConvPixl Pix2 Stratiform Rain R Z Coefficient Pixel 1 2 Number of epsilon on convective rain observations Number of epsilon on stratiform rain observations Number of epsilonO on stratiform rain observations Same as the above but for stratiform rain Same as the above but for convective rain Estimated number of rain observations at range gate to surface rain certain only Same as the above but for stratiform rain Same as the above but for convective rain The category of shallow rain and shallow isolated rain is exclusive Number of shallow rain observations Number of shallow isolated rain observations Number of observations including rain and no rain Number of observations for which bright band is present which is calculated in 2A25 processing which is calculated in 2A25 processing Number of epsilonO on convective rain observations which is calculated in 2A25 processing which is calculated in 2A25 processing Number of R Z coefficient pixel counts for near surface and 2km heights R Z Coefficient are a and b in the following formula 7 Same the above but for convective
165. er oceans in 5 x 5 grids for probRain one month f Relationship with Other Algorithms 3A11 is the final product and is not input to any other algorithms TRMM DATA USERSHANDBOOK 4 1 3 VIRS VIRS Data product and outline of its algorithm is explained hereafter The structure of 1B01 product is described in the later section 4 2 4 3 4 1 3 1 Product Definition VIRS data product is shown in Table 4 1 3 Table 4 1 3 VIRS Product 1801 VIRS Radiance to which radiometric and geometric correction is carried out 4 1 3 2 Processing Algorithm 1 1 01 Processing a Processing Description IB 01 data is performed geolocation and calibration for VIRS Level 1A product b Output Data of 1B01 Processing The outputs of 1B01 processing are listed in below Meta Data Same as the meta data in PR products Scan Time Scan Time is the observation year date and time The exact scan time relationship between Scan Time and the time of each IFOV is described in the section 4 2 3 7 Geolocation The earth location of the center of the IFOV at the altitude of the geolocation earth ellipsoid Off earth 1s represented as less than or equal to 9999 9 Scan Status The status of each scan It includes quality platform and instrument Scan status control data orbit number and so on Navigation Same as the navigation in PR products navigation Solar Cal The three components of the solar unit
166. er of layers of latent heating TRMM DATA USERSHANDBOOK Sigma D hat 2 bytes Array ECS Core Metadata 10 000 bytes P5 Metadata 10 000 bytes Data Granule Table Navigation 88 bytes Table R hat 2 bytes Array SwathData Array latentHeatHH 4 bytes Array spare 4 bytes Array Figure 4 2 17 Data Format Structure for 2B31 2 3B31 Monthly Rainfall nscan ngeo x nray x nscan nscan nscan x nscan nray x nscan Nradarrange x nray x nscan Nradarrange x nray x nscan nray x nscan x nscan nlayer x nr y x nscan 4 x nray x nscan The 3B31 is grid data and it is stored in the Planetary Grid structure 5 x 5 Figure 4 2 18 shows the structure of the 3B31 product in terms of the component objects and their sizes The following sizing parameter is used in describing this format nlat 16 the number of 5 grid intervals of latitude from 40 N to 40 S nlon 72 the number of 5 grid intervals of longitude from 180 W to 180 E nlayer 14 the number of profiling layers within one pixel Section4 OUTLINE OF THE TRMM PRODUCTS BCS Core Metadata bytes PS Metadata LOO betes Data Granule S000 bytes sferam TM Abhytes J Amy nim x dh bytes Array niat x nion 4 bytes J Array niai x nlon x nlaver Array x nlayer Armay x nlon x mayer Le i ray nii x nlon x nluyer F anaterytinio NS x
167. ere no events prior to the events at time 0 and that the pixel grid is 0 02 wide in latitude and longitude In general the Section4 OUTLINE OF THE TRMM PRODUCTS latitude longitude grid in earth based coordinates and the pixel grid will not be the same size or coregistered In addition the times will be time from the start of the orbit a Time 0 ms The first time integration 1 shown Figure 4 1 13 Three 1 2 3 events occur at this time integration Since the events are simultaneous and register in adjacent 1 neighboring or diagonal pixels they are collected into a single group a The group is assigned a new parent flash A and the new flash is assigned a new parent area Time ms Event Group Flash Area I i tn a A Au rn Figure 4 1 13 Time integration at Oms b Time 100 ms The next time integration with data is shown in Figure 4 1 14 At this time 100 ms after the first one there are three more events 4 5 6 As in the previous case these three new events are all assigned to a new group b These events are not assigned to group a since they occur at a different time Since group b is within 5 5 km of group a actually they touch and the groups occur within 330 ms of each other group b is assigned to flash A and therefore area a TRMM DATA USERSHANDBOOK Time 100 ms Event Group Flash Area 1 rr 2 M 5 um ad 67 er omm Figure 4 1 14 Time
168. es JAXA EOC reconfiguration requiring S C VIRS amp TMI Inputs to reconfiguration Instrument Mission spacecraft Scientists VIRS TMI SS cienti 2 weeks Instrument anng CERES LIS TOET Activities Timeline Activities Timeline report to remote users Planning Aids TDRS schedule FOT SOCC conflict resolution Operation requests from engineers CERES amp LIS Instrument Scientists Can t Resolve 1 week OM Joint TRMM Science Resolved Team conflict sie at EEEE resolution MOC Generate Resolved Activity 3 4 days SEDE Plan Problem Perform Load Load Review Generation and Approval Remote users include R T system LaRC MSFC TSDIS Uplink 1 day JAXA via TSDIS FDF Command Load Figure 2 5 2 Instrument Planning and Scheduling Operations Table 2 5 2 Spacecraft Maneuvers 180 Yaw Delta V 90 Yaw CERES Deep Space Activity Keep the Sun off the Orbit Attitude PR Antenna Pattern Calibra e Y side of spacecraft Maintenance Measurement Two 50 sec burns Activity Duration 17 minutes 35 minutes non contiguous spaced by 45 minutes rs within 48 hours Settling Time includes m ey about 5 minutes about 3 minutes duration duration every other day MOL of sensor checkout Standby Normal Normal Contamination safe Contamination safe Normal Normal 2 25 Section2 OUTLINE OF T
169. ess were first subtracted and then soil wetness was estimated The upper panel of Figure 6 4 4 is the estimated soil wetness for February 1998 and the lower panel is for August 1998 Comparing the estimates for February and August the Amazon River basin in South America is wet in February during the rainy season and dries up in August corresponding to the dry season The Orinoco river basin which is adjacent to north of the Amazon behaves in the opposite manner Wetting in the Asian Monsoon region is dominant as well In the false color composite maps of PR backscattering various patterns are recognized in desert areas However the Sahara desert and the Rub al Khali desert are classified as arid regions in these quantitatively estimated soil wetness maps In some mountainous areas where the scattering theory of dependency of incident angle cannot be applied due to the effects of steep slopes and in some tropical rainforest areas where the forest is extremely dense soil wetness cannot be estimated by this algorithm Such regions are shown in black as missing data areas The black region in the Northwestern part of Australia indicates missing PR observation data due to the frequency conflict 6 14 TRMM DATA USERS HANDBOOK gt Dry No 1 se ga aa as nr ne pm 1p Soir Wia Figure 6 4 4 Soil Wetness Estimated from PR 4 Long wave Top of Atmosphere Flux Figure 6 4 5 shows th
170. f calibration coefficients reception coefficient transmission coefficient and FCIF input output characteristic table used for precipitation radar Level 1 processing Also it has a function to test and verify the products generated in the precipitation radar data processing system for quality control and a function to re name and register the NASA products 2 Main Functions The main functions of the verification facility are as follows a Calculation management of calibration coefficients b Verification inspection of the products c Registration of the NASA products 3 2 3 Operation Planning Facility 1 Outline This facility carries out operation planning to determine what commands are to be transmitted for operation of the precipitation radar as well as requesting and coordination with NASA NASA MOC will carry out command operations such as changing the precipitation radar modes based on the coordination results 37 Section3 OUTLINE OF THE GROUND SYSTEMS 2 Main functions The main functions of the operation planning facility are as follows a Management of the orbit data b Display of observation area c ARC operation simulation d Making of PR operation requests e Management of MOC reports f Making of quick look data processing requests g Making of data transmission plan 3 2 4 Precipitation Radar Calibrator ARC 1 Outline The precipitation radar is a system whereby rainfall rate
171. files and brightness temperature TRMM has the only passive microwave instrument TMI in an inclined orbit and the only rain radar PR in space The three rain instruments are providing the most complete rain data set to date in order to generate climate models and perform severe storm studies The two additional instruments flown on board TRMM are the CERES and LIS CERES and LIS are flown on board TRMM as instruments of opportunity for the Earth Observation System Program The CERES instrument measures the Earth s radiation budget and the LIS instrument investigates the global distribution of lightning 2 2 1 Precipitation Radar PR 2 2 1 1 Mission Overview The Precipitation Radar PR is the primary instrument onboard TRMM The most innovative of the five TRMM instruments the PR is the first quantitative rain radar instrument to be flown in space The major objectives of the PR instrument are as follows a Provides a 3 dimensional rainfall structure b Achieves quantitative measurements of the rain rates over both land and ocean When properly combined with TMI measurements the PR data 15 instrumental in obtaining the height profile of the precipitation content from which the profile of latent heat release from the Earth can be estimated The rain rate is estimated from the radar reflectivity factor when the rain rate is small by applying conventional algorithms used for ground based radar For large rain rates a rain atten
172. formation Service as well as the related products to help users to utilize the earth observation satellite data Users receive online services to be provided by the EOIS through the Internet 5 1 Outline of EOIS Services The outline of EOIS services are listed in the table 5 1 1 Table 5 1 1 EOIS Data Services ce Inventory Inforetion Service amp eeSwh Same Daa Dowo Oo gt o Duas amp Swh imgCadg __ DisiyofimgeCddog Oo Editing of rege Catalog oO a ObsewdionArmimdcde Oo i ee eee en o datas Ord Smam sasen Product Users can use EOIS data services shown in the table 5 1 1 by accessing to Data search amp Order menu in the EOC web site www eoc jaxa jp homepage html The outline of EOIS services are explained in the following sections of this document For more detail EOIS User s Manual is available for registered users and general users respectively Users can obtain the EOIS User s Manual from the web site of EOIS data services 1 Catalog Information Search Search for standard products catalog information is provided The following items are available as the search key an observation date period a pair of latitude and longitude a data set name a satellite name a sensor name and other optional search key items
173. g View Time Unlike many of the other instruments on TRMM the LIS data is very dependent on how long a particular location was viewed by the LIS instrument For a single pass different locations on the ground can have a wide range 0 to 80 seconds of view times The amount of lightning in a location is not very useful without information on how long it took to produce that amount of lightning To provide this information to the users of the LIS data view time information is calculated for each point along the LIS field of view h One Second Data The LIS data are also very dependent on the status of the LIS instrument The one second data provides this information as a series of one second snapshots of internal and external instrument parameters 2 Algorithm Mathematical Description a Example Data Processing Sequence The purpose of this section is to graphically describe the algorithm that accumulate the individual LIS events into groups flashes and areas by walking through a typical LIS data scenario In this illustrative exercise all times indicated are times after the first event time Numbers indicate event numbers while lowercase letters represent the groups The flashes are designated by capital letters and the areas are indicated by Greek letters Each subsequent section describes how the algorithm processes the events that occurred at that integration time For the purpose of this demonstration it is assumed that there w
174. gapore JAXA s meteorological radar located in Tibet as a part of GEWEX Asian Monsoon Experiment GAME this radar was used at Miyako Island Kagoshima and Wakasa Gulf And then routine observation using the radar has been performed at Tanegashima Moreover cross calibration of TRMM data has been performed with sonde data and ground 6 6 TRMM DATA USERS HANDBOOK radar data that were acquired simultaneously during the convergence observation of GAME Additionally TRMM data is compared with the rain measurement network data covering all of Japan using telemeters and also verified by rainfall data from TMI The following is an example of the TRMM verification result by several types of radar data Figure 6 2 1 shows the validation result of PR data with ground radar data of Ishigaki Island Consistency between both data is very well but with a little deviation Ground radar of Ishigaki Island has been technically calibrated and the error of receiving level is within 1 dB 2425 E a i SHIGAS daz Figure 6 2 1 Cross Calibration between TRMM PR and Ground Radar at Ishigaki Island The CAMPR operates at 13 8 GHz that is just the same as the frequency of TRMM PR and makes down looking rainfall observations similar to TRMM PR The CAMPR has spatial resolutions and the sensitivity much higher than those of TRMM PR and has functions of multi polarization and Doppler observations Therefore com
175. gistration 50 Representative location within the bin For example if the center of the bin is the most representative location the value CENTER would be used Currently no other values have been defined Latitude Resolution 50 North south size of a bin degrees latitude Longitude Resolution 50 East west size of a bin degrees longitude Coordinate Coordinate Coordinate Coordinate Origin of the grid indices For example SOUTHWEST 4 71 Section4 OUTLINE OF THE TRMM PRODUCTS Unless otherwise specified bin meth and registration CENTER TSDIS Planetary Grids will always have North Bounding Coordinate 40 South Bounding Coordinate 40 West Bounding Coordinate 180 East Bounding Coordinate 180 and Origin SOUTHWEST Unless otherwise specified Latitude Resolution Longitude Resolution 5 Each Data Grid is an SDS with dimensions Y x nlat x where Y is the number of variables and nlat and nlon are the number of North South and East West grid points respectively The names of the latitude and longitude dimensions are Latitude X and Longitude X where X is the name of the Data Grid SDS Other dimensions have the names specified in the Swath description The name of the SDS is the name of the variable contained in the grid One TSDIS product 3A 25 has grids at two different resolutions requiring 2 Grid Structures and a different naming conventio
176. gorithm Theoretical Basis Document ATBD for the Lightning Imaging Sensor LIS 4 78 TRMM DATA USERSHANDBOOK 4 2 4 1 PR The following parameters are used in describing format of PR products Level 1 amp Level 27 nray 49 the number of rays within one PR scan line nscan 9150 the number of PR scans within one granule when orbit altitude is 350 km on average nscan 9250 the number of PR scans within one granule when orbit altitude is 402 5 km on average ngeo 2 the number of geolocation data ncelll 80 the number of radar range cells at which the rain rate is estimated ncell2 5 the number of radar range cells at which the Z R parameters are output nmeth 2 the number of methods used lt Level 3 gt nlat 16 the number of 5 grid intervals of latitude from 40 N to 40 S nlon 72 the number of 5 grid intervals of longitude from 180 W to 180 E nlath 48 the number of 0 5 grid intervals of latitude from 37 N to 37 S nlonh 720 the number of 0 5 grid intervals of longitude 180 W to 180 E nhl 6 the number of fixed heights above the earth ellipsoid at 2 4 6 10 and 15 km plus one for path average nh2 3 the number of fixed heights above the earth ellipsoid at 2 4 and 6 km nh3 4 the number of fixed heights above the earth ellipsoid at 2 4 and 6 km plus one for path average 25 the first number of categories for histo
177. grams ncat2 30 the second number of categories for histograms 1 1B21 Calibrated Received Power The 1B21 is stored as a Swath Structure in HDF Figure 4 2 7 shows the structure of the 1B21 product in terms of its component objects and their sizes 4 79 Section4 OUTLINE OF THE TRMM PRODUCTS ECS Core Metadata 10 000 bytes Product Specifsc Metadata 10 000 bytes PR Cal Coef Table 18 Ray Header 60 bytes Table Data Granule Svea CASO SCL S000 bytes Geaolecatian Scan Status 15 bytes Navigation bytes Table System Noise 2 bybes Array System Noise Warning Flag SwathData gie Bin Start of Oversample 2 bytes Array Bin Clutter Free Bottom Surface Oversample Rain Oversample 2 bybes Array Figure 4 2 7 Data Format Structure for 1B21 1C21 Radar Reflectivities 2 Scan Time B bytes Table 4 bybes Array Fable 7 byte Array Fi Minimum Echo Flag 1 byte Array Satellite Local Zenith Angle 4 bytes Array 3 Spacecraft Range 4 bytes Array 2 bybes Array Bin DIDH Tap 2 bytes Array Normal Sample 2 bytes Array 2 bytes Array nscari 2 nray x nscan nscan nscan nray x nscan nray x nscan nay x necari Z X nray x nscan nray x nscarn nray x nscan 2x28 x Scan nray x nscarn iray x nscan nray x Scan nray x scan 2 Xx
178. h gimbal will be restricted to rotate in a range between 110 and 250 The switch in instrument operation between the two azimuth rotation ranges is performed via stored commands whose times of execution are based on predicted values of beta angle The restricted azimuth rotation range 110 to 250 is necessary to prevent the detectors from scanning closer than 20 to the Sun during sunrise and sunset CERES calibrations will be performed every two weeks The elevation of the Sun during Solar calibrations will be 11 and the azimuth of the instrument will be set to correspond with the elevation angle so that the Sun 1s in the field of view of the MAM Mirror Attenuator Mosaic Solar calibrations will be performed according to the preprogrammed sequence in the instrument s microprocessor CERES will be commanded to Standby mode and then execute the 2 29 Section2 OUTLINE OF THE TRMM SATELLITE calibration The sequence will last about 30 minutes and will return the instrument to the Standby mode upon completion An internal calibration will normally be performed immediately after completion of a solar calibration The internal calibration sequence turns the internal calibration sources on and off in a preprogrammed sequence Calibration data are acquired while the elevation gimbal performs a normal Earth scan profile and the instrument is operating in either the Cross track or Bi axial scan mode A Deep Space Calibration will
179. h vertical layer from 2B31 in each 5 x 5 grid Surface rain from 2A12 where 2A12 and 2B31 overlap monthly accumulated in each 5 x 5 grid Convective surface rain from 2A12 where 2A12 and 2B31 overlap monthly accumulated in each 5 x 5 grid Surface rain from 2B31 where 2A12 and 2B31 overlap monthly accumulated in each 5 x 5 grid The ratio of 2B31 to 2A12 surface rain fall calculated from the swath overlap region for each 5 x 5 grid TRMM DATA USERSHANDBOOK Cloud Liquid Water 2 93 Monthly mean cloud liquid water from 2A12 at each vertical layer cloudWater in each 5 x 5 grid Precipitation Water TMI g m Monthly mean precipitation water from 2A12 at each vertical layer rainWaterTMI in each 5 x 5 grid Cloud Ice Water g m Monthly mean cloud ice water from 2A12 at each vertical layer in each 5 5 grid Graupel g m Monthly mean graupel from 2A12 at each vertical layer in each 5 graupel x 5 grid Latent Heating C h Monthly mean latent heating from 2A12 at each vertical layer in latentHeat each 5 x 5 grid d Relationship with Other Algorithms The output of 3B31 is used for 3B42 and 3B43 3 3B42 Processing a Processing Description The objective of 3B42 is to provide a precipitation estimate in the TRMM region that has the nearly zero bias of the TRMM Combined Instrument precipitation estimate and the dense sampli
180. hapter it is also given an outline about the future plan of TRMM mission Main events after launch of TRMM are shown as follows 6 1 Section6 TRMM OPERATION STATUS RESULTS and FUTURE PLAN Table 6 1 Events of TRMM Mission Date JST Events 1997 November 28 Launch by JAXA H II launch vehicle No 6 from Tanegashima Space Center December 1 2 PR is powered on December Orbit maneuvering from initial orbit altitude 380 km to nominal orbit altitude 350 km December 8 Start of the PR initial check out on orbit December 9 Archive the PR first image December 17 Press release of the PR TMI LIS first images 1998 Middle of January Completion of the PR initial check out on orbit TRMM campaign was carried out in the area of May ee ES Ishigaki Island and Miyako Island June 1 TRMM level 1 products were released September 1 All levels of TRMM products were released TRMM campaign was carried out again in the area EN Mayr dp omes of Ishigaki Island and Miyako Island November Re processing of PR data by software version 5 was started Near real time image data distribution service by EORC has been operational Symposium commemorating the third anniversary iN vemberag of the launch of the TRMM satellite was held Completion of designed mission line and start of January 31 post operations February 1 Field experiments of AMSR
181. he sporadic El Ni o phenomenon 12 TRMM DATA USERSHANDBOOK e d Wam IP J Cole amp Eub Eurface Wakar Warm Water Cold Bub Pnrilic Bain Maritime Continent Continent Ww Figure 1 3 1 Tropical Rainfall and Climate Anomaly Nominal left figure Anomaly right figure Provided by NASA Main science missions of TRMM are 1 Monitor tropical rain rate quantitatively and understand the earth s energy and hydrological cycle 2 Clarify the actual condition of temporal and spatial changes of tropical rainfall and mechanism to have an effect on atmospheric circulation and evaluate and develop the numerical model to reproduce and predict them 3 Establish the method to observe rainfall from space TRMM completed its nominal three years mission in January 2001 and is continuing to operate Based on the latest mission analysis about necessary fuel for a controlled reentry TRMM lifetime will be 1 5 years shorter than the previous estimate Consequently the satellite altitude was raised to about 400km in August 2001 in order to extend observation period After that although the remaining fuel was at its limit for controlled reentry in September 2005 JAXA and NASA decided to continue the mission until September 30 2009 for the long term scientific achievements of TRMM instead of the reentry 1 4 Responsibilities of US and Japan The TRMM project was proposed and approved at the SSLG held
182. he threshold defined in the parameter file it is currently set to 3 dB then the lowest range bin at which Zm is above the noise threshold is chosen as the near surface range bin Near surface Z factor The definition of Near Surface is same as the above Non Uniform Beam Filling NUBF correction factor PIA 15 calculated from the Z factor which is corrected by using hybrid method of HB and SRT 422 TRMM DATA USERSHANDBOOK Precipitation Water Parameter A PrecipWaterPaqram A Precipitation Water Parameter B PrecipWaterPaqram B Precipitation Water summation PrecipWaterSum Quality Flag qualityFlag Rain Rate mm h rain Rain Rate Average mm h cm h rainAve Rain Flag rainFlag Rain Type rainType Range Bin Number rangeBinNum Reliability Flag reliab Satellite Local Zenith Angle deg scLocalZenith Sigma Zero dB sigmaZero zeta C zeta Average of zeta zeta mn Standard Deviation of zeta zeta sd Maximum of Z Factor dBZ zmmax Rain Rate Parameter a ZRParmA Rain Rate Parameter b ZRParmB Coefficient A in the relation PWC AZeP between the precipitation water content PWC and Ze at 5 nodal points The values between the nodes can be calculated by linear interpolation Coefficient B in the relation PWC AZeP between the precipitation water content PWC and Ze at 5 nodal points The values between the nodes can be calculated by
183. hi Sammary tas Sacer Wal Seco Bg Info V Hg Data Summary Ws Hg Dain SD8 a Science Data b Background Image Data Figure 4 1 12 LIS HDF File Components Table 4 1 6 Outline of LIS Data Products Description Orbit Orbit Attribute LISO7 The beginning and end times of the granule per the TRMM defined orbit Orbit Summary LISO7 Summary of the areas flashes groups events and backgrounds occurring between the start and stop time of the orbit Browse Browse Area 11509 Browse 2 5 latitude longitude grid Vector Statistics Image Attributes LIS02 Background Arca 11506 Flash 11505 Total radiance in the flash flash t of groups sequentially separated in time by no more than 330ms ccurrence of a single pixel exceedi Group 11504 Total radiance in group group one or more events in the same time frame se Event 11803 Calibrated event radiance event the ng a threshold for 2ms Flash density LISIO Number of flashes in the 500 km grid View Time One Second Data EB series of one second snapshots of internal and external instrument Information of time period to observe lightning parameters A text description of the LIS parameters unique to this orbit Meta Data 4 1 6 2 Processing Algorithm The occurrence of lightning is accompanied by the sudden release of electrical energy which 15 converted into rapid heating in the vicinity of the lightning channel
184. ias TOA flux errors for all scenes are expected to be a factor of 3 4 smaller than those for the ERBE like analysis In addition to improved TOA fluxes this subsystem also provides the CERES FOV matched cloud properties used by subsystem 5 to calculate radiative fluxes at the surface within the atmosphere and at the TOA for each CERES FOV Finally this subsystem also provides estimates of surface fluxes using direct TOA to surface parameterizations This subsystem has been decomposed into six additional subsystems Imager clear sky determination and cloud detection Imager cloud height determination For ISCCP this step is part of the cloud property determination Cloud optical property retrieval Convolution of imager cloud properties with CERES footprint point spread function CERES inversion to instantaneous TOA fluxes Empirical estimates of shortwave and longwave surface radiation budget involving CERES measurements 5 Subsystem 5 Compute Surface and Atmospheric Fluxes ATMOSPHERE Data Product This subsystem is commonly known as SARB Surface and Atmospheric Radiation Budget and uses an alternate approach to obtain surface radiative fluxes as well as obtaining estimates of radiative fluxes at predefined levels within the atmosphere All SARB fluxes include SW and LW fluxes for both up and down components at all defined output levels from the surface to the TOA For Release 2 output levels are the surface 500 hPa t
185. ibution Pre selected products are staged on a server for a pre defined period allowing downloading via the Internet This service is available to all users including general users Sample data can be downloaded by clicking Sample data button in the scene search result screen If sample data is not ready user can apply for acquiring sample data For specific product names refer to Table5 4 2 Table 5 3 5 Sarrple Data Provided tho Full scene fixed region sub scene 1C21 2A25 sub scene are selectable Full scene only 1B21 2A21 2A23 3A25 3A26 Full scene sub scene are selectable 1B11 2A12 Full scene only COMB Full scene sub scene are selectable Full scene only 3B31 3B42 3B43 Fixed Region Sub scene Region over Japan which covers 80 to 160 degree East Longitude and 5 degree South to 35 degree North Latitude Sub scene Lat Long 10 degree gridded data TRMM DATA USERS HANDBOOK 6 TRMM OPERATION STATUS RESULTS and FUTURE PLAN TRMM was launched in November 1997 and after that various results have been reported until now In this chapter it is introduced around the information related to the PR about the results of initial check out on orbit calibration and validation research products etc Moreover TRMM increases the smooth result more than it was expected and an active examination is being carried out about Global Precipitation Measurement GPM of the succession satellite of TRMM In this c
186. ier and divides them to 128 systems using divider combiner 1 and divider combiner 2 It then carries out power amplification using the power amplifiers SSPA connected to each system and supplies it to the antenna subsystem SSPAs use saturation power and have high output stability They operate in the saturation region with plenty of margin The transmit receive subsystem also amplifies the 128 systems of the received signals that are supplied from the antenna subsystem using low noise amplifiers LNA and combines them using divider combiner 2 and divider combiner 1 It then supplies the combined signal to the signal processing subsystem after it has been amplified by the receive drive amplifier A phase shifter is integrated in divider combiner 2 and it controls the phase relationship between the 128 systems of transmission signals as well as between the 128 systems of received signals This function ensures that the antenna beams are scanned in a specified direction The power to SSPAs LNAs divider combiner 2 and transmit receive drive amplifiers are supplied from the power source of the transmit receive subsystem 1 Power Amplifier SSPA a Structure SSPA are categorized largely into two groups by circuit structure and further into 18 groups by drive amplitude SSPA18 is installed with a coaxial waveguide converter and it also does not have a circulator in the output board It is distinguished from other SSPA and is called the Transm
187. igure 5 3 1 Example of Order Sheet for TRMM PR scene order 5 3 2 Data Providing Flow The steps from user s data request to data providing are explained below and by Figure 5 3 2 1 User requests TRMM data by using an order sheet PI is allowed to submit a scene order by online through EOIS 2 JAXA checks an order and makes a work order 3 User requested product is copied on distribution media and sent to user Where all of master data are produced regularly and archived based on a pre set plan TRMM DATA USERSHANDBOOK JAXA Internal Users Organizations based on an agreement Co investigators Order Desk Level 0 Data Products Order Reception JAXA Data Media Check Work Order Processing gt Conversion Distribution Media Shipping Accounting Users Research Purpose sers d Figure 5 3 2 Diagram of order flow from request to provision 5 3 3 TRMM Distribution Media Each TRMM distribution product is produced as follows The distribution media of TRMM data products is shown in Table 5 3 4 Each product can be provided only on HDF 1 Products of PR TMI VIRS and COMB can be distributed on the same format as that of master product no format conversion It will be produced per each product sensor processing level type of data set full scene sub scene
188. imum the necessity of each algorithm developer codifying their own I O routines These routines are designed so that algorithm developers can easily use them at their research centers This means that these routines include basic functions used by the majority of algorithm developers The second objective of the tool kits is to allow the simple incorporation of TRMM algorithms into TSDIS computer environments TSDIS treats received algorithms as black boxes it is fundamental that interface with TSDIS is defined consistently in the algorithms In this way tool kit development concentrates on these routines that are intrinsic in interaction with TSDIS computer environments Tool kit routine categories that have been developed are described in Section 2 of ICS The routines are selected from each category and describe a general outline of how they are used This is continued in the same fashion in Section 3 where there are explanations with examples of how each routine is used A parameter dictionary is also provided for the calling sequence of each routine which defines each parameter This parameter dictionary is used by algorithm developers to find out where each parameter is used Tool kits routines are codified in line with file specifications in ICS release 2 volume 3 level 1 file specifications and volume 4 level 2 and 3 specifications The current release release 6 44 of the TSDIS tool kits is supported by DEC SGI Sun HP and
189. in June 1986 and since then it has being promoted as a joint project between US and Japan mainly by NASA and JAXA Table 1 4 1 shows the responsibilities of US and Japan on the development and operation of the TRMM systems and Table 1 4 2 shows the responsibilities on the data processing 13 1 INTRODUCTION TRMM is a US Japan joint project In the project Japan CRL Communications Research Laboratory Currently named NICT National Institute of Information and Communications Technology and JAXA provided the Precipitation Radar PR and the launch of the TRMM satellite by H II rocket The US provided the spacecraft bus and the four sensors except for the PR and operates the TRMM satellite NASA Goddard Space Flight Center GSFC via Tracking and Data Relay Satellite TDRS performs the on orbit spacecraft operation Table 1 4 1 Responsibilities of US and Japan related to development and S C operation PespmimRawgn Seamer Clouds andthe Radiant Energy CERES Telemetry and science observation data of TRMM is formatted in CCSDS packet basis and then transmitted to the White Sands station via TDRS Pre processing Level 0 processing of all data and higher level processing of PR TMI and VIRS data is conducted at GSFC Level 0 processed CERES and LIS data is transmi
190. in rate at the surface for each pixel The Convective Surface Rain is the instantaneous convective rain rate at the surface for each pixel The Confidence 1 that associated with the surface rain It reflects an rms deviation in temperatures and the number of good database profiles went into the retrieval This is the cloud liquid water content for each pixel at 14 layers This is the precipitation water content for each pixel at 14 layers This is the cloud ice water content for each pixel at 14 layers This is the precipitation content for each pixel at 14 layers This is the heating C hour due to phase change and eddy heat flux for each pixel at 14 levels In 2A12 product moreover the same information as 1 11 is recorded about Meta data Scan time Geolocation Scan status and Navigation 4 38 TRMM DATA USERSHANDBOOK e Relationship with Other Algorithms The output of 2A12 is used for 2B31 3B31 and 3B42 Assign surface type to each pixel DB Water Land Mixed Others a simple regression oe type of algorithm clear sky conditions topographic data base Clear sky Caliculate Total Vaper Clear sky flag on Volume Cloud check TB signature is compatible with clouds y interpolate the pixel value cloud only flag on Cloud Model Profile Generate new Cloud Model Profile Over min RMS dev
191. inates system is the system to adjust alignment to the satellite almost coincides with the Radar Mechanical coordinates system The Radar Mechanical coordinates system rotates around the y axis by 92 92 q1 so that the beam will face to nadir when scan angle is 0 The beam direction in the Radar Mechanical coordinates system is as follows 0 D S 0 TEM 0 i 0 Scan angle measurement value the definition of sign refers to Figure 2 6 12 S 9 Rotation matrix when scan angle 9 TEM Conversion matrix from the Radar Electric coordinates system to the Radar Mechanical coordinates system Based on above formula the beam direction D in the Satellite Mechanical coordinates system is as follows Ds TA I Du Conversion matrix from the Alignment coordinates system to the Satellite Mechanical coordinates system Ta Conversion matrix from the Radar Mechanical coordinates system to the Alignment coordinates system Section2 OUTLINE OF THE TRMM SATELLITE The beam track at ground is illustrated in Figure 2 6 13 The error from the cross track occurs because of the flight velocity of the satellite 2s E lectr ic coord inate is ME A Sat Ilite coord nate ax is Figure 2 6 12 Coordinates Axes of the Satellite and PR 10 T T T T T 5 F 8 Satdliteflight direction ET Scan direction 5 w Sh Sceangdd 4 Scan angie
192. infall Measuring Mission TRMM Precipitation Radar Algorithm Instruction Manual except 1A21 1 1A21 Processing In 1A21 processing a scene unit from the south end to the south end of the orbit is extracted from PR Level 0 data which is continuous observation data from UT 00 00 00 to UT 24 00 00 and sampling of a packet necessary for PR data processing is carried out Editing and conversion to an engineering value is carried out to HK data and orbital data corresponding to this timing and the databases necessary for following processes are prepared The functional structure of 1A21 processing is shown in Figure 4 1 3 and the relationships 4 5 Section4 OUTLINE OF THE TRMM PRODUCTS between processing functions are shown in Figure 4 1 4 The contents of each function are explained below a Checking input data The files specified by the parameter file are checked to see if they can be processed and if there is any abnormality the operator is notified and the processing is terminated Also HK data are isolated by each APID b Checking the continuity of the packet The sequence count within the header record of the PR Level 0 data is checked and the packet is rearranged in an ascending order The consistency between the sequence count and the time code is also checked and if there is any inconsistency time correction is carried out c Extraction of scenes UTCF is calculated from ACS time and time code stor
193. ion e g generate a data set at 0600 1200 1800 and 2400 Universal Time Coordinated UTC each day containing all data units received since the last data set generation h 3 A fixed relative spacecraft time period containing all data units received between two relative spacecraft times e g generate a data set from data units received from spacecraft between H1 hour date and H2 hour date i Available for transmission to the consumer within 24 hours following the receipt of the last source data unit for that routine production data set 4 1 Section4 OUTLINE OF THE TRMM PRODUCTS 4 Data Product provides TRMM data products shown in Table 4 1 1 The TRMM algorithm flow diagram shows in Figure 4 1 1 Table 4 1 1 TRMM Products Estimated Sensor Processing Level Product Scene Unit Volume pem pressed Calibrated Received Power 1 orbit 16 day Be ane 1 21 Radar Reflectivity 1 orbit 16 day ym Normalized Radar Surface Cross Section O 0 2423 PR Qualitative 1 orbit 16 day P 2A25 Rain Profile 1 orbit 16 day c uh a 3A25 Monthly Statistics of Global Map Monthly 62 MB Rain Parameter Grid 5 x 5 0 5 x 0 5 35 38 MB 3A26 Monthly Rain Rate Global Map Monthly 10 MB using a Statistical Method Grid 5 x 5 5 6 MB 1 11 Brightness Temperature 1 orbit 16 day a 2 12 Rain Profile 1 orbit 16 day EIE Global Map
194. ion vector to calculate the satellite range The observation position vector is found from the beam direction vector expressed in GCI system the satellite position vector and the satellite range and the longitude and latitude of the observation position for each angle bin is calculated in WGS 84 system Expresses the satellite position in zenith angle and azimuth angle Also seeks the vertical northern and eastern constituent unit vectors in the observation point expressed in GCI system 4 96 TRMM DATA USERSHANDBOOK 4 4 OrbitViewer The orbit viewer is the TRMM data viewer which is developed by NASA TSDIS It is freely distributed from NASA TSDIS and JAXA EORC The Orbit Viewer is prepared from the following home page EORC URL http www eorc jaxa jp TRMM gt for UNIX Windows and Linux TSDIS URL http tisdis gsfc nasa gov for UNIX Windows Linux and MacOS The Orbit Viewer makes it easy to perform an initial examination of TRMM data files The viewer allows you to display TRMM data at the full instrument resolution on a map of the tropics Vertical cross sections and 3D images of rain structure can also be created a Horizontal View b Vertical View Figure 4 4 1 Sample Display of Orbit Viewer 4 97 TRMM DATA USERSHANDBOOK 5 EOIS DATA SERVICE The Earth Observation Data and Information System EOIS is a user front end system that offers the Earth Observation Satellite Data Catalog In
195. is then converted into dummy data Also if the determined scan status of Level 1B product data is data with a poor quality geolocation abnormality then it is converted into dummy data b Calculation of Z factor The radar constant Cj is calculated from the value of 1B21 Ray Header Rain scattering received power P is calculated from the received power and noise level of 1B21 and then a dummy radar reflectivity factor Zm is calculated by using radar equation The radar reflectivity factor is dummy because it does not isolate noise deficit during propagation such as atmosphere attenuation and because it is calculated in a state that contain these values c Output Data of 1C21 Processing The file format is exactly the same as that of 1B21 except for the replacement of the received power by the radar reflectivity factor including rain attenuation and noise no echo range bin by 414 TRMM DATA USERSHANDBOOK a dummy value d Relationship with Other Algorithms The output of 1B21 is used for 2A25 and 2B31 1C21 Processing Function Input Data Check Calculation of Z factor including rain attenuation Figure 4 1 7 Function structure of 1C21 processing Birinas Data Tone mi Posear Haing Anwar Dor Caiculysna Kebr onan zx Width ith Ani Crom Deracrion Sor Ania can F iuo weld nde uat ig
196. ists of an Inertial Reference Unit IRU with three two axis gyros two Three Axis Magnetometers TAM two Coarse Sun Sensor CSS units 8 sensors total two two axis Digital Sun Sensor DSS units three dual wound Magnetic Torque Bars MTBs a single Earth Sensor Assembly ESA a prime and backup Attitude Control Electronics ACE four Reaction Wheel Assemblies RWA a prime and redundant ACS Processor housed in the FDS and an Engine Valve Driver EVD The Gimbal and Solar Array Control Electronics GSACE controls the High Gain Antenna System HGAS and the Solar Array Drive Assemblies SADA Figure 2 1 3 provides a block diagram of the ACS Coarse Sun Sensors 8 Digital Sun Sensors 2 um Inertial Reference B Unit Three 2 Axes Three Axes _ Flight Data System A Magnetometers 2 Attitude Control Electronics A Reaction Wheels 4 ii Magnetic Torquer i Bars 3 Engine Valve Driver A amp B Flight Data System 01 Earth Sensor Assembly Attitude Control System A Solar GsacEs Gimbal Solar Array Control Electronics A Figure 2 1 3 ACS Block Diagram 2 4 TRMM DATA USERSHANDBOOK 2 1 3 Electrical Subsystem ES The ES provides power switching and distribution optical command and telemetry routing and discrete telemetry and command distribution The ES also provides pyrotechnics launch vehicle interface support
197. it Drive Amplifier TDA TDA is used to amplify the RF signals supplied from the signal processing subsystem to a level necessary for input into the divider combiner 1 2 44 TRMM DATA USERSHANDBOOK b 1 2 3 4 2 Function Possesses an output power satisfying the conditions of the transmission antenna pattern Possesses a circulator used to separate the transmission signals to the antenna and the received signals from the antenna Carries out transmit control using control signals Possesses an output power monitoring function Low Noise Amplifier LNA Structure LNA are categorized into 18 groups by gain LNA18 is installed with a coaxial waveguide converter and is called the Receiver Drive Amplifier RDA RDA is used to amplify the RF signals output from the divider combiner 1 to a level necessary for input into transmit receive subsystem b Function 1 Possesses a gain satisfying the conditions of reception antenna pattern 2 Possesses a T R switch used to protect LNA and to prevent effects on other circuits caused by transmit pulse leakage during transmission 3 Carries out T R switch control by control signals 3 Divider Combiner 1 Function a Function 1 During transmission it inputs the RF transmission pulses supplied from the frequency converter IF assembly of the signal processing subsystem and outputs them to the divider combiner 2 after branching them into 16 2 During
198. itioned on rain type Histogram of storm top height conditioned on stratiform rain 4 31 Section4 OUTLINE OF THE TRMM PRODUCTS Height of Storm Top convective rain convStornHH Snow Depth snowIceLH xi 0 xiH NUBF Correction Factor nubfH Convective Rain Rate Epsilon epsilonConvH Stratiform Rain Rate Epsilon epsilonStratH Convective Rain Rate Epsilon0 epsilon ConvH Stratiform Rain Rate EpsilonO epsilon0StratH Histogram of storm top height conditioned convective rain Histogram of snow depth only when bright band is present Histogram of which is calculated in 2A25 processing Histogram of Non Uniform Beam Filling NUBF correction factor which is calculated in 2A25 processing Histogram of epsilon on convective rain observations which is calculated in 2A25 processing Histogram of epsilon on stratiform rain observations which is calculated in 2A25 processing Histogram of epsilonO on convective rain observations which is calculated in 2A25 processing Histogram of 0 on stratiform rain observations which is calculated in 2A25 processing The following parameters are defined as output of 5 x 5 grid Nadir direction BB HH statistics bbNadirHH Nadir direction BB WidthH statistics bbNadirWidthH Nadir direction BB ZmaxH statistics bbNadirZmaxH d Correlation Coefficients Histogram of bright band heights from n
199. k Lower Deck Aft Skirt Stub Skirt Intercostals m bo Propellant Tank Module LISP Lower Instrument Support Platform ISP Instrument Support Platform UISP Upper Instrument Support Platform RWM Reaction Wheel RW Module Inertial Reference Unit IRU Mounting Plate The UISP supports TMI VIRS four thrusters for orbit maneuver and front omni antenna The ISP supports RW IRU and PR PR is mounted to the ISP and LBS by using kinematic mount CERES and LIS are mounted to the LISP Stub Skirt is jointed to PAF of H II launch vehicle by using marman clamp Main material of STR is Aluminum 6061 T651 Aluminum 7075 T73 Aluminum 7050 T7451 and Aluminum Honeycomb In the kinematic mount for PR mounting A mount three degree of freedom and B mount two degree of freedom are manufactured by Titanium Each element of STR is joined by using mainly Aluminum rivets 2 9 Section2 OUTLINE OF THE TRMM SATELLITE 2 2 Overview of the Onboard Instruments The TRMM observatory includes five science instruments namely the Precipitation Radar PR TRMM Microwave Imager TMI the Visible and Infrared Scanner VIRS the Clouds and the Earth s Radiant Energy System CERES and the Lightning Imaging Sensor LIS TRMM has three instruments PR TMI and VIRS in its rainfall measurement package to obtain tropical and subtropical rainfall measurements rain pro
200. l and Normal year January 1999 lower panel observed by the TMI Nama JAN 1998 qu _ Figure 6 4 1 Rainfall Distribution in January 1998 1999 Upper 1998 El Nino year Lower 1999 Normal year 6 12 TRMM DATA USERS HANDBOOK JAN 1998 i LI 4 T d 4 E BDE E rao XEM AW Figure 6 4 2 Sea Surface Temperature from TMI 2 Simultaneous Observation by Several Sensors The images in Figure 6 4 3 are simultaneous images over northern Argentina and Uruguay from the VIRS TMI and PR on February 20 1998 Figure 6 4 3 1 is a color composite RGB image of channels 1 visible 2 near infrared and 4 infrared for red green and blue respectively observed by VIRS Figure 6 4 3 2 shows the 85 GHz vertically polarized brightness temperature observed by TMI Figure 6 4 3 3 shows the horizontal cross section of rain at 2 0 km height by PR Figure 6 4 3 4 shows the vertical cross section rain along the line AB in Figure 6 4 3 3 Optically thicker cloud at the upper layers are reddish in Figure 1 because of the high reflectivity of channel 1 and their low temperature Figure 6 4 3 3 shows that rainfall was observed in these areas It is clear in Figure 6 4 3 4 that the heavy rain developed in the layer above the heavy rain in the lower layers Generally there were ice crystals over the rain which developed at high altitudes The brightness temperature in Figure 6 4 3 2 decreased due to mic
201. led programmers who wish to make HDF do something more than what is currently available through the higher level interfaces Low level routines are only available in C The HDF application programming interfaces or APIs include several independent sets of routines with each set specifically designed to simplify the process of storing and accessing one type of data These APIs are represented in Figure 4 2 2 as the second layer from the top Although each interface requires programming all the low level details can be ignored In most cases all one must do is make the correct function call at the correct time and the interface will take care of the rest Most HDF API routines are available in both FORTRAN 77 and C These are included NCSA HDF Utilities described in 4 4 1 1 The routines that make up the low level interface and the APIs are available in the NCSA HDF libraries Source code for the HDF libraries as well as binaries for some platforms is in the public domain and is on the NCSA ftp server at hdf ncsa uiuc edu On the highest general applications level HDF includes command line utilities for managing and viewing HDF files NCSA applications that support data visualization and analysis and a variety of third party applications HDF utilities are included in the NCSA HDF distribution Applications supported by NCSA as well as applications contributed by members of the world wide HDF user community are freely available on the NC
202. louds 6 3 Section6 TRMM OPERATION STATUS RESULTS and FUTURE PLAN Cyclone Pam acquired by TRMM PR Dee H IT 1757 18102 UTC Horizontal Distribution of rainfall Altitude 2 0km uH Te EL irin CHES OWL WA Figure 6 1 1 1 2 PR First Image Cyclone TRMM DATA USERS HANDBOOK Rainfalls in Okinawa area hy TRMM PR Denk 1997 17 34 07 24 UTC Horizontal distributiun of rainfall Altitude i 2 Om enasna M 134 m das IR DLO UTC by WA Figure 6 1 1 2 2 PR First Image Okinawa 6 5 Section6 TRMM OPERATION STATUS RESULTS and FUTURE PLAN 6 2 PR Calibration and Validation Result Receiving sensitivity of PR is validated periodically by using ARC located at a branch of NICT Kansai Advanced Research Center KARC in western part of Japan At present the status of PR is very good and it was confirmed that error of receiving level was within 1 dB based on the internal calibration result ARC data and sea surface scattering data without rain Moreover unlike ground radars bad influence of anomalous spread or clutter is lower and the data is very clean On the other hand it was suggested that PR data includes a little error because weak rain may not be observed due to the limitation of radar sensitivity Additionally extremely weak echo was found in clutter due to the antenna side lobe However the reason of these err
203. luding rain attenuation Also rain no rain is determined for each angle bin a flag is set up and the rain height is calculated Moreover influence of surface clutter which is mixed from antenna main lobe and side lobe is evaluated and the evaluation result is reflected to the calculation of surface range bin number and the determination of rain no rain Function structure of 1B21 processing is shown in Figure 4 1 5 and the relationship between the processing functions is shown in Figure 4 1 6 The contents of each function are explained below a Editing the observation mode data Based on the input parameter file name science telemetry data for only during observation mode for one calibration cycle 3 minutes as well as HK data already converted into an engineering value from the Level 1A file are read If special mode data is contained in the read data dummy data is set up If packet deficit exists within the read calibration cycle dummy data is set up at the applicable location Also if packet deficit exists at the beginning of a scene dummy data for an applicable period is output With science telemetry data special mode the header section is added and is output to the calibration mode data file b Calculation of radiometric information PR estimated temperature is calculated from the panel temperature telemetry data already converted into an engineering value within the read PR HK data Also transmission level and tra
204. ly averaged into CERES 1 degree equal angle grid boxes using functions described in subsystem 6 The outputs consist of mean and statistics of VIS and IR narrowband radiances for each of the CERES 1 degree grid box and each of the 3 hourly synoptic time This data product represents a major input source for both subsystem 7 and 10 12 Subsystem 12 Regrid Humidity and Temperature Fields This subsystem describes interpolation procedures used to convert temperature water vapor ozone aerosols and passive microwave column water vapor obtained from diverse sources to the spatial and temporal resolution required by various CERES subsystems Most of the inputs come from EOS DAO or NOAA NCEP analysis products although the subsystem accepts the inputs from many different sources on many different grids The outputs consist of the same meteorological fields as the inputs but at a uniform spatial and temporal resolution necessary to meet the requirements of the other CERES processing subsystems Interpolation methods vary depending on the nature of the field For Release 2 CERES is planning to use the DAO analysis products One of the key issues for use of analysis products in a climate data set is the freezing of the analysis product algorithms during the climate record DAO has agreed to provide a consistent analysis method for CERES 4 1 6 LIS LIS data products and their algorithm is explained hereafter 4 1 6 1 Product Definition The
205. m Conical Scan 49 deg 8 8 kbps 50 kg 39 W For pre orbit boost See Section 2 7 5 about parameters of post orbit boost August 2001 Table 2 2 5 TMI Observation Characteristics Polari Integral Footprint size km wadh time Perpendicular to zation nu Scan direction H 500 7 37 0 H 2000 6 6 16 0 92 8 85 5 V 3000 33 72 46 9 85 5 H 3000 33 13 46 For pre orbit boost See Section 2 7 5 about parameters of post orbit boost August 2001 Table 2 2 6 TMI Observation Performance Center Freq Polari Beam Receiving EN FOE 1065 V 1065 H 3 9 Vapr 56 1 i i V H V H Land Ocean Land Ocean Strong rain Land Light rain Ocean Strong rain Land 2 2 3 Visible and Infrared Scanner VIRS 2 2 3 1 Mission Overview The VIRS instrument is a cross track scanning radiometer which measures scene radiance in five spectral bands operating in the visible through infrared spectral regions VIRS is similar to instruments flown on other NASA and NOAA meteorological satellites Comparison of the microwave data with VIRS visible and infrared data is expected to provide the means whereby 2 13 Section2 OUTLINE OF THE TRMM SATELLITE precipitation can be estimated more accurately than by visible and infrared data alone The VIRS instrument serves as a background imager and provides the cloud context within which
206. mbly 2 Digital Sun Sensor 3 Inertial Reference Unit 4 Three Axis Magnetometer Although the orbit parameter of TRMM changed a little with change of orbit altitude it is hardly changing On the other hand attitude of TRMM is controlled by using data from DSS Digital Sun Sensor IRU Inertial Reference Unit gyro and TAM Three Axis Magnetometers via Kalman filter because ESA Earth Sensor Assembly is not available outside the altitude range from 335 to 390 km However comparatively big fluctuation of attitude was found for about three months after orbit boost Section2 OUTLINE OF THE TRMM SATELLITE 2 7 3 Operation of PR Due to change of orbit altitude characteristics of PR are modified The modification points are listed in table 2 7 2 Table 2 7 2 Comparative Table of PR Characteristics before and after Orbit Boost Pre Boost Post Boost Horizontal Data Spacing 4 3 km 5km cross track 4 3 km along track Footprint Size 4 34km 0 12 km at nadir 5km Minimum Detectable Rain Rate 0 5 mm h 0 7 mm h Swath Width 215 220 km 245 250 km Observable Echo Height gt 15 km gt 13 5 km Global Data Sampling 8 days 10 14 days Changes in PR parameters are 1 Change of footprint size and swath width due to inclination of distance 2 Degradation of sensitivity minimum detectable rain rate 3 Change of data spacing and day interval for global data sampling due to orbit parameter
207. ment to test next generation algorithms for possible use in the operational environment The basic SOCC functions are e Coordination between instrument scientists of TMI VIRS and PR and MOC 3 19 Section3 OUTLINE OF THE GROUND SYSTEMS e Provide access to MOC real time display e Support instruments scientists to monitor house keeping data of instruments The basic RST functions are e Interface to the supported science users e Supports query browse display and ordering e Mechanism for receiving instrument scheduling requests and distributing MOC produced planning aids instrument scientists only may submit scheduling requests 3 4 7 Langley Research Center LaRC LaRC is responsible for the CERES instrument although daily instrument operations are managed by the FOT A real time telemetry monitoring capability is provided at the LaRC CERES Instrument Monitoring System while data handling from the SDPF is the responsibility of the LaRC Distributed Active Archive Center DAAC LaRC possesses a MOC remote terminal interface to allow monitoring of the CERES instrument health and safety 3 4 8 Marshall Space Flight Center MSFC MSFC is responsible for the LIS instrument A real time telemetry monitoring capability is provided at the MSFC LIS Instrument Support Terminal while data handling from the SDPF is the responsibility of the MSFC DAAC MSFC possesses a MOC remote terminal interface for the monitoring
208. ming requirements execution of time tagged commands onboard data storage and a capability to store commands and tables The C amp DH also provides dual telemetry output I and Q Channels and various telemetry encoding schemes Reed Solomon R S Cyclic Redundancy Checks CRC and Convolutional Encoding The C amp DH consists of two strings designated as prime and redundant Each string includes the following components Uplink card Downlink card Clock card Spacecraft Processor ACS Processor 2 2 Gbits of memory Data storage of approximately 210 minutes is provided by C amp DH in the form of solid state recorders Bulk Memory Cards Figure 2 1 2 provides a block diagram of the TRMM C amp DH 2 2 TRMM DATA USERSHANDBOOK subsystem FLIGHT DATA SYSTEM FDS SIDE 1773 BUS Bq ACS PROCESSOR to Side B Uplink I F SPACECRAFT 1773 BUS Downlink I F F 3 F to FDS B from FDS B Downlink Downlink I F GSTDN CHANNEL LVPC Low Voltage Power Connector S C Spacecraft GSTDN Ground Station Figure 2 1 2 C amp DH Subsystem Block Diagram 23 Section2 OUTLINE OF THE TRMM SATELLITE 2 1 2 Attitude Control Subsystem ACS The ACS provides autonomous control of the observatory and maintains pointing control to 0 4 and pointing knowledge to 0 2 Redundant hardware and software is provided to meet the science objectives The ACS cons
209. ms 1 2 Scope This document consists of six sections and appendices Section 1 Describes the purpose and scope of the document and the overview of TRMM mission Section2 Introduces the specifications of the TRMM satellite system and mission instruments the outline of TRMM orbit and the TRMM operation policy Section3 Introduces the outline of the ground systems of and NASA National Aeronautics and Space Administration Section 4 Explains the outline of TRMM products provided by JAXA and HDF format and introduces various toolkits Section 5 Presents the outline of TRMM products services provided by JAXA EOIS Section 6 Explains TRMM mission status results and future plan Appendices Provide acronym list and reference information l1 1 INTRODUCTION 1 3 TRMM Mission Recent increasing interest for the earth s environment has identified the importance to grasp the global climate change and understand the mechanisms The hydrological cycle is a centerpiece of the Earth system and a key to understanding its behavior Among various components of the water budget tropical rainfall which comprises more than two thirds of global rainfall is the primary driver of global atmospheric circulation as a hot source Knowledge of the tropical rainfall and its variability is therefore crucial to understand and to predict the global climate system In spite of its important role in our lives an
210. n has the least rapidly varying index To implement this format in FORTRAN declare an array with dimensions as they appear in this document To implement the format in C declare an array with dimensions reversed from their appearance in this document 4 2 3 5 Orbit and Granule Definition The beginning and ending time of an orbit is defined as the time when the sub satellite track reaches its southernmost latitude This time is determined from the definitive ephemeris data A scan is included in an orbit when its Scan Time is greater than or equal to the Orbit Start Time and less than the Orbit End Time The average orbit is 91 5 minutes or 5490 seconds The first partial orbit after launch will be orbit 1 so the first full orbit will be orbit 2 A granule is defined as one orbit for the VIRS and PR instruments For the TMI instrument a granule is defined as one orbit plus an overlap before the orbit known as the Preorbit Overlap plus an overlap after the orbit known as the Postorbit Overlap The overlap size is fixed at exactly 50 scans Since there are two overlap periods per granule each granule will contain 100 overlap scans See Figure 4 2 6 Multiple granules Single granule ee BS Co C A Figure 4 2 6 Granule Structure Time Increases Toward the Right Overlaps are used to allow algorithm 2B 31 to open only one input granule in order to output one granule The overlap is needed because 2B 31 requires both TMI
211. n control of the SPRU The SPRU provides peak power from the solar array and charge control for the batteries using Voltage Temperature and Constant Current Control circuitry The PBIU contains the battery and bus relays and directs power to the Essential and Non Essential busses It also contains the battery and bus current shunts for monitoring current flow through the system Figure 2 1 5 shows a block diagram of the PWR PSE Electronics Power System Interface Box PSIB Standard Power Regulator Unit SPRU Power Bus Interface Unit PBIU Batteries Essential Bus Power Signal Figure 2 1 5 Power Subsystem Block Diagram 2 1 5 Radio Frequency Communications Subsystem COMM The COMM is designed to provide real time communications through the TDRS Space Network SN This is accomplished by using the deployable HGA or the two Omni antennas The HGA antenna will provide nearly hemi spherical coverage and the Omni antennas will also provide nearly spherical coverage The TRMM design includes two NASA Standard Second Generation User Transponders Figure 2 1 6 shows a block diagram of the COMM for TRMM 2 6 TRMM DATA USERSHANDBOOK Antennas RF Combiner TRANSPONDER A LJ E Directional Couplers LI Figure 2 1 6 RF Communications Subsystem Block Diagram 2 1 6 Thermal Subsystem THM The THM provides the components and equipment in order to maintain the thermal environment of the observatory du
212. n than above In this product there are two Vgroups with the names PlanetaryGridl and PlanetaryGrid2 and there are two GridStructures with the names GridStructurel and GridStructure2 To avoid repetitious text certain defaults are used in this document for the formats of a Data Grid SDS unless otherwise specified the names of the dimensions are as above 4 2 3 Formatting Conventions 4 2 3 File Structure Figures The figures that illustrate file structure contain either Vgroups or data objects metadata objects SDSs or Vdatas Figure 4 2 5 is an example of a product structure with annotations shown in italics Vgroups are represented as the name of the Vgroup without a box Data objects are represented as the name of the object inside a box For metadata objects the estimated maximum total size appears on the right hand side of the box If the object is a Vdata table the size of one record appears on the right side of the box and the number of records appears next to the box If the object is a SDS array the size of one element appears on the right side of the box and the dimensions of the array appear next to the box The sizes for the metadata objects are estimated maximal since the values of many metadata are free text and may vary in length and not all metadata elements are used for all products None of the sizes take HDF overhead into account Previous unpublished experience gained in the TSDIS prototype study and the HDF internal f
213. nd its reliability factors are included 3A 11 TMI Monthly Oceanic Rainfall which is monthly accumulated rainfall on 5 x 5 grid 4 1 2 2 Processing Algorithm Processing algorithm for products in Table 4 1 2 1 explained hereafter 1 1B11 Processing a Processing Description Product 1B 11 is performed geolocation and calibration for TMI Level 1A data b Output Data of 1B11 Processing The outputs of 1B11 processing are listed in below Meta Data Same as the meta data in PR products Scan Time Scan Time is the observation year date and time The exact scan time relationship between Scan Time and the time of each IFOV is described in the section 4 2 3 7 Geolocation The earth location of the center of the IFOV of the high resolution geolocation 85 GHz channels Off earth 1 represented as less than or equal to 9999 9 435 Section4 OUTLINE OF THE TRMM PRODUCTS Scan Status scan status tmi Navigation navigation Calibration calibration Calibration Counts calCounts Satellite Local Zenith Angle deg satLocZenAngle Low Resolution Channels K lowResCh High Resolution Channels K highResCh The status of each scan It includes quality platform and instrument control data orbit number and so on Same as the navigation in PR products Necessary information to calibrate TMI data Hot load temperature receiver temperature and so on
214. ng The all acquired data will be transmitted to the Sensor Data Processing Facility SDPF in GSFC by online and then the data will be processed to level 0 data within 48 hours after observation preprocessed mission data at SDPF will be transmitted to the TSDIS in GSFC and then processed to higher products Where the CERES level 0 data will be sent to LaRC the LIS level 0 data will be sent to MFSC and at the respective center the higher products will be generated and distributed to users The PR level 0 data will be transmitted to Japan from SDPF by online the data will be processed to higher products at JAXA EOC In addition the level 1 data of TMI and VIRS will be transmitted from TSDIS to JAXA EOC by online as well The other sensors products which are processed in US will be transported to EOC using media and then distributed to Japanese users After November 2005 the standard products of TMI VIRS and COMB that were processed by NASA will be able to be acquired from TSDIS to JAXA EOC by online And also JAXA EORC will perform the analysis and research using the TRMM data generate data sets for research purposes and provide them to researchers Since autumn of 1999 NASA has started the distribution service of near real time data JAXA EOC has gotten the near real time data of PR 2A25 R1 PR 2A25 R2 and TMI 1B11 from TSDIS by online and then forwarded them to the Japan Meteorological Agency JMA since November 2
215. ng calculates qualitative value for rainfall Using 1C21 as input data 2A23 outputs the rain no rain flag the rain type and the height of rainfall In rain type classification detection of bright band is carried out first If bright band is detected its height is calculated Rain type classification is carried out based on the vertical profile of radar reflectivity factor Z and horizontal distribution of Z When the bright band exists or when rain is weak and the bright band is possible rain is classified as stratiform When Z is large or Z stands out against the background Z of rain area rain 1 classified as convective The third category of rain 1 others which consist of cloud and or noise Shallow isolated rain is classified as convective in version 6 of 2A23 b Input Data of 2A23 Processing For 2A23 processing the following input data are read from 1C21 Meta Data Observation start stop time orbit radius etc Ray Header Start Range Bin Number of Normal Sample Main lobe Clutter edge Side lobe Clutter Range Scan Status Geolocation Information Minimum Echo Flag Range Bin Storm Height Range Bin Number of Ellipsoid Range Bin Number of Clutter free Bottom Range Bin Number of Mean DID Satellite Local Zenith Angle Satellite Range Oversample Range Bin Start Land Ocean Flag Bin Number of Surface Peak Normal Sample Surface Oversample Rain Oversample Additionally sea surface
216. ng of geosynchronous IR imagery 3B42 is composed of two separate algorithms which are 1 to produce monthly IR calibration parameters and 2 to calibrate the merged IR precipitation data to produce the daily adjusted merged IR precipitation and RMS precipitation error estimates a Calculation of Monthly IR Calibration Parameters Processing consists of verifying the validity of the VIRS radiance 1B01 and TMI rain profile 2A12 converting the VIRS radiance data to precipitation rates using the Geosynchronous Precipitation Index GPI accumulating the number of ambiguous TMI observations and accumulating the VIRS and TMI precipitation rate data on a 0 25 x 0 25 grid in a global band extending from 50 south to 50 north latitude The VIRS and TMI precipitation rate data along with the corresponding observation count data are accumulated When the accumulation of the VIRS and TMI precipitation data is completed for the orbit the orbit averages of the accumulated VIRS and TMI precipitation rate data are computed and then clipped to coincident observations These clipped precipitation rate and observation count data are then added to the calendar monthly clipped VIRS and clipped TMI data accumulator files respectively The orbit average unclipped TMI precipitation rate and observation count data are added to the calendar monthly unclipped TMI data accumulator file this file is used for 3B43 processing When the month period flag is
217. ng the oversample The status of the onboard surface tracker 1s attached 0 normal 1 Lock off The bin surface peak indicates the logical range bin number of the peak surface echo If the surface 1 not detected Bin Surface Peak is set to a value of 9999 4 11 Section4 OUTLINE OF THE TRMM PRODUCTS Normal Sample dBm 100 normalSample Surface Oversample dBm 100 osSurf Rain Oversample dBm 100 osRain The normal sampled PR received powers are recorded The data is stored in the array of 49 angles x 140 elements Since each angle has a different number of samples the elements after the end of sample are filled with a value of 32767 If a scan is missing the elements are filled with the value 32734 The PR records the over sampled data in five range bins around the surface peak detected on board not Bin Surface Peak in a total of 29 angle bins nadir 14 angles to examine the surface peak precisely The PR records the over sampled data at 28 range bins in a total of 11 angle bins nadir 5 angles to record the detailed vertical profile of the rain i Relationship with Other Algorithms The output of 1B21 is used for 1C21 and 2A21 1B21 Processing Function Editing of the observation mode Calculation of radiometric information Calculation of geometric information Conversion to received power value Calculation of ground surface echo Calculation ofthe minimum echo Primary
218. ng up down heat mixing and aqua circulation due to the precipitation activities The precipitation estimation accuracy of microwave radiometer and visible and infrared radiometer is improved by referring of the rainfall vertical construction observed by satellite radar The visible and infrared radiometer data of SSM Is AVHRR and stationary satellite has been already stored and will be also observed in the future The precipitation estimation accuracy is improved for these visible and infrared radiometer data observed by SSM I AVHRR and stationary satellite TRMM follow on will be improved about following items comparing to TRMM 2 Observation coverage will be extended from Tropical region up to higher latitude region Improvement on observation accuracy and sensitivity will be expected by two frequency radar Classification between precipitation and snow will be realized Outline of the Global Precipitation Measurement GPM GPM is a program to observe precipitation with several small polar satellites carrying a microwave radiometer and one core satellite In this program eight small satellites are planned from partner agency and they globally observe precipitation with the time resolution of three hours And the TRMM follow on is placed as the core satellite of this system The estimated values with the microwave radiometers can be improved by the data measured by the Dual Frequency Precipitation Radar DPR of the core sa
219. nique is used to find reference data of sea surface scattering coefficient Hybrid Technique is that approximate scattering coefficient at quadratic curve in the cross track direction Orthogonal direction to traveling direction using spatial averaged reference data When there is reference data in five angle bin or more for every angle bin and calculate reference data for every angle bin If reference data are calculated by Hybrid Technique reference data by the technique instead of reference data that were averaged for time and spatial were used However they are same to Version 5 for one of land For rain Path Integrated Attenuation PIA is calculated based on the surface reference data of no rain area This PIA is used to calculate rainfall profile in 2A25 as Surface Reference Data using Surface Reference Technique SRT b Input Data of 2A21 Processing For 2A21 processing the following input data are read from 1B21 Geolocation Information System Noise Minimum Echo Flag Bin Number of Surface Peak Satellite Local Zenith Angle Range Bin Number of Ellipsoid Normal Sample Surface Oversample Spacecraft Range Scan Time c Intermediate Data of 2A21 Processing Time averaged scattering coefficient Every month d Output data of 2A21 Processing The outputs of 2A21 processing are listed in below Sigma Zero dB Normalized backscattering radar cross section of the surface for the sigmaZero 49
220. no commanding is intended for the remainder of the mission General health and safety monitoring of the TMI instrument during real time events will be performed and the SOCC will be notified of any anomalous behavior 2 5 2 3 VIRS Commanding of the VIRS instrument will normally be minimal Switching VIRS from the Day mode to the Night mode will be accomplished by the spacecraft telemetry and statistics monitoring TSM capability The spacecraft processor will monitor for day night conditions using the PSIB time of day telemetry The TSM will monitor for night conditions and then 2 27 Section2 OUTLINE OF THE TRMM SATELLITE trigger an RTS The RTS will wait three minutes command VIRS to Night mode wait 20 minutes and then command VIRS back to Day Mode This will occur every orbit Solar calibrations will be performed approximately every 1 3 weeks when the Sun is in the field of view of the solar calibrator door Planning aids will be utilized by the VIRS Instrument Scientist to determine specific times of the calibration Those times will be communicated via the SOCC to the FOT for the inclusion of calibration commands into the daily spacecraft command load Two commands will be necessary for the VIRS solar calibration a calibration door open and a calibration door close command An 180 yaw maneuver will be performed every two to four weeks when the Sun reaches a Beta angle of 0 in order to keep the Sun off the side
221. ns developers need not know how to consistently use safely the special resources of TSDIS The tool kits also provide a common use single source Science algorithms use numerous mathematical scientific and engineering functions and these can be isolated into different libraries The use of these libraries boosts the conformity of algorithms and algorithm processing results Table 4 3 1 is a list of tool kit categories created to enable use by algorithm developers Details of specification routines and their calling sequences are in TSU TSDIS ICS Interface Control Specifications Tool Kit User s Guide Vol 2 Table 4 3 1 Tool Kit Categories Tool Kit Category Input Output Tool Kit Carried out read write for data and metadata Mathematical Tool Kit General mathematical routine Conversion Tool Kit Carries out constants units data and time conversion Geolocation Tool Kit Carries out calculation of geolocation of picture elements geometrical position Error Handling General error processing This section provides a brief introduction of TSDIS tool kit routines The purpose of the tool kits is twofold the first being to provide sets of common functions constants and macros for use by algorithm developers These common items are prepared in the tool kit to reduce the volume of code development 492 TRMM DATA USERSHANDBOOK being carried out simultaneously by algorithm developers This will for example reduce to a min
222. nsmission pulse width corresponding to the FCIF estimated temperature are calculated Items required for radiometric information RF PS voltage temperature telemetry already converted into engineering values IPSDU temperature and current SSPA power monitor LOGAMP monitor and noise level average value are output to the verification file regulated by the program c Calculation of geometric information Satellite position information during observation time and position information on the foot print of each beam angle are calculated based on the orbit data file Geolocation TOOLKIT provided by NASA is used for this processing d Conversion into received power value A received power vs count value table considering the gain loss factor is created to convert the count value obtained from telemetry data to a received power value Based on this table the normal echo sample of science data surface echo over sample and rain echo over sample are TRMM DATA USERSHANDBOOK converted into received power value e Calculation of ground surface echo The start range bin number of an over sample is calculated based on the ground surface echo position of science telemetry data Also the range bin number of peak surface echo is detected from the altitude data derived from the normal echo sample surface echo over sample and the topographic database DID DTED Intermediate Dataset Moreover the range bin number corresponding to the lowest
223. nter wavelength um 10 80 12 00 Band width um 00 006 SNR NEAT 0 06K 0 06K 0 06K Calibration accuracy 10 1 5 5 5 2 24 Clouds and the Earth s Radiant Energy System CERES 2 2 4 1 Mission Overview The CERES experiment will help reduce one of the major uncertainties in predicting long term changes in the Earth s climate Radiant fluxes at the top of the Earth s atmosphere TOA were measured by the Earth Radiation Budget Experiment ERBE not merely as an undifferentiated field but with reasonable separation between fluxes originating from clear and cloudy atmospheres It was also discovered from ERBE that clouds have a greater affect on the TOA fluxes than was previously believed but details of the process are not yet fully understood The CERES experiment will attempt to provide a better understanding of how different cloud processes such as convective activity and boundary layer meteorology affect the TOA fluxes This understanding will help determine the radiative flux divergence which enters directly into physically based extended range weather and climate forecasting CERES will also provide information to determine the surface radiation budget which is important in atmospheric energetics studies of biological productivity and air sea energy transfer 2 15 Section2 OUTLINE OF THE TRMM SATELLITE Since September 1998 however CERES operated intermittently to acquire science data for only campaign purpose
224. ntified as 11504 Although a group may often correspond to a single lightning optical pulse it is also possible that multiple lightning pulses occurring within the 2 ms integration window may contribute to a group A false event due to noise at a pixel exceeding the background threshold can also contribute to a group although noise groups often contain only one event d Flash A lightning flash consists of one to multiple optical pulses that occur in the same storm cell within a specified time and distance A lightning flash should then correspond to several related groups in a limited area For the LIS algorithm we define a flash as a set of groups sequentially separated in time by no more than 330 ms and in space by no more than 5 5 km The temporal and spatial rules can be easily adjusted in the LIS algorithm processing software We will continue to examine the rules closely during the analysis of OTD and early LIS data to fine tune the rules defining a flash A flash may include as few as one group with a single event or it may consist of many groups each containing many events Since there is the possibility that the TRMM satellite will move a significant fraction of a pixel during the time of a flash spatial characteristics for a flash and all higher level parameters are calculated in ground coordinates i e latitude and longitude resolution A flash is identified as 11505 We 4 59 Section4 OUTLINE OF THE TRMM PRODUCTS
225. of instrument health and safety 3 4 9 Space Network SN The SN is the term given to the elements which comprise the real time support network utilizing the TDRS communications satellite The TDRS spacecraft along with its ground terminal is used for the throughput transmission of telemetry and command data to and from the MOC Personnel at the ground terminal will assist through the NCC during anomalous communications conditions All nominal real time supports will be accomplished via the SN TRMM data will be forwarded to the MOC in TDRS 4800 bit Nascom block format 3 4 10 Wallops Flight Facility WFF The ground tracking station at the Wallops Flight Facility WFF Virginia is used for contingency support during the L amp IOC phase of the mission In addition WFF is used for 3 20 TRMM DATA USERS HANDBOOK contingency support throughout the mission In the event of an anomaly real time and playback telemetry data will be downlinked via WFF Real time telemetry will be stripped and shipped to the MOC in real time and recorder playback data will be stored on site for post pass playback to the MOC and SDPF TRMM data will be forwarded to the MOC in DDPS 4800 bit Nascom block format 3 21 TRMM DATA USERSHANDBOOK 4 OUTLINE OF THE TRMM PRODUCTS TRMM observed data are processed by NASA and JAXA and distributed to users Table 4 1 provides definition of the TRMM products Table 4 1 The definition of the TRMM
226. of spacecraft The maneuver will be performed in darkness during eclipse to avoid the possibility of the Sun shining on the VIRS Normal operations for the VIRS instrument will consist of general health and safety monitoring of instrument housekeeping data during real time operations Thermal monitoring of VIRS will also be included VIRS contains operational heaters that can provide four discrete amounts of heater power to the VIRS scanner to maintain its temperature within a 0 to 20 range The operational heaters are commandable via the command link Limits will be set and monitored on the ground during real time events Figure 2 5 4 shows the operational temperature ranges EOL HOT CASE CONDITION Hot Limit o 4 ce o Restricted Operati onal Temperature Range Cold Limit ulk Scanner Temperature C m 20 5 1 15 20 Power Di ssipated in Scanner W Figure 2 5 4 Thermal Monitoring 2 28 TRMM DATA USERSHANDBOOK 2 5 2 4 CERES CERES instrument commanding will be more frequent than any of the other instruments The majority of instrument commands will be issued from the spacecraft SCP Stored Command Processor CERES instrument activities will be pre approved by LaRC and then the activities will be planned by the FOT During normal science operations the instrument will operate in the Cross track and the Biaxial Scan modes 66 and 33 of the time respectively Operations in these t
227. ogeneity by performing separate radiative computations for up to two non overlapped cloud layers in each CERES FOV The average CERES FOV optical depth for each cloud layer is defined by averaging the logarithm of imager pixel optical depth values using the assumption that albedo varies more linearly with the logarithm of optical depth 6 Subsystem 6 Grid Single Satellite Fluxes and Clouds and Compute Spatial Averages ATMOSPHERE Data Product The next step in the processing of the CERES Atmosphere Data Products is to grid the output data from subsystem 5 0 into the EOS standard 1 degree equal angle grid boxes 7 Subsystem 7 Time Interpolation and Synoptic Flux Computation for Single and Multiple Satellites ATMOSPHERE Data Product The CERES strategy is to incorporate 3 hourly geostationary radiance data to provide a correction for diurnal cycles which are insufficiently sampled by CERES The key to this strategy is to use the geostationary data to supplement the shape of the diurnal cycle but then use the CERES observations as the absolute reference to anchor the more poorly calibrated geostationary data One advantage of this method is that it produces 3 hourly synoptic radiation fields for use in global model testing and for improved examination of diurnal cycles of clouds and radiation The output of subsystem 7 is an estimate of cloud properties and surface atmosphere and TOA fluxes at each 3 hourly synoptic time These estimates are
228. olocation Scan Conducts geometric calculations in line with the following module GEOreadEphem interpolation routines to calculate satellite position velocity vector at the start of scanning with GCI geocentric inertial coordinates system GEOnadirtoGCI Uses satellite interpolation position velocity vector and rotational angle velocity of the earth to calculate satellite velocity vectors taking into consideration the earth s rotation and calculates Nadir GCI conversion matrix GEOcalculateGHA Calculates the Greenwich hour angle from the Julian calendar of the necessary time taking into consideration notation GEOelipsx Finds the satellite range satellite altitude from the Nadir Z direction vector expressed in GCI system and the satellite position vector and calculates the observation position vector GEOconv2ECoord Calculates the latitude and longitude of the satellite position for angle bin number 1 when S expressed in WGS 84 system GEOextractAttd Finds satellite ACS conversion matrix and ACS Nadir conversion matrix and combines with Nadir GCI conversion matrix to calculate the satellite GCI conversion attitude matrix matmpy Calculates sensor GCI matrix from attitude matrix and alignment matrix Input attdm attitude matrix GEOearthLocate Converts the beam direction vector sensor system into a beam direction vector GCI system using the sensor GCI conversion matrix This is used with the satellite posit
229. on the specified storage period for each data the data will be stored and managed with a disc or an automatic tape library In addition data storage with shelves and external storage will be managed by this system 3 3 3 Schedule Management System 1 Schedule Management Subsystem The Schedule Management Subsystem is the system to input and edit order information grasp production status manage transport of deliverables and manage stock and order of distribution media 2 Information Retrieval Subsystem The Information Retrieval Subsystem is the system to register and manage processing information and provides a response to query from other subsystems to its requestor It generates inventory information based on scene information and processing information and provides the information to the Information Service System 313 Section3 OUTLINE OF THE GROUND SYSTEMS 3 3 4 Catalogue Data Distribution System Browse Data Distribution Subsystem The Browse Data Distribution Subsystem is the system to generate and manage sampling data and compression data as the image catalog data and to distribute the data to users by a network The major processing for image catalog generation is as follows Data compression JPEG DCT Addition of annotation Data enhancement such as liner stretching Users can use this image catalog retrieval services by online through the Information Service System 3 3 5 On Line Information
230. oned within the heat sinking planes is covered with multilayer insulation MLI Beta cross is used for the outermost layer of the taking into consideration the anti atomic oxygen Loaded instruments with high calorific value RF PS and FCIF are positioned on the plane panel and the Y plane panel respectively Because RF PS and FCIF are both of redundant structure primary redundant systems are installed on the same heat sink taking into consideration the thermal control of the redundant side instruments The heat from RF PS and is directly radiated from the OSR heat sinking plane of the Y plane panels The center panel where transmit receive electronic instruments such SSPA LNA DIV COMB 1 DIV COMB 2 SCDP and PLO unit are installed is placed with a heat pipe This enables a design with uniform heat distribution within the center panel and a small heat distortion Instrument heat from the center panel is designed to be radiated to space through the heat radiation bonding with the antenna section Installed instruments and panel on the installed instruments side are coated with black paint to increase the heat radiation bonding In the safe hold mode in which loaded instruments are inoperative a survival heater is employed in order not to lower the lower limit of the permissible temperature of the loaded instruments The survival heater is controlled by a mechanical thermostat 2 50 TRMM DATA USERSHANDBOOK
231. ons of 1B21 processing sse 4 13 Figure 4 1 7 Function structure of 1C21 processing 4 15 Figure 4 1 8 Relationship between functions of 1C21 processing 4 15 Figure 4 1 9 TMI Level 2A 12 Process Flow Diagram n nns 4 39 Figure 4 1 10 CERES Data Flow Diagram esee eee nen enne nennen nnne enn 4 49 Figure 4 1 11 The scan pattern of two CERES scanners on EOS AM and EOS PM spacecraft 4 51 Figure 4 1 12 LIS HDF File Components 4 57 Figure 4 1 T3 Time integration at OMS edet e rete t ieri ive e ree oet P era 4 62 TRMM DATA USERS HANDBOOK Figure 4 1 14 Figure 4 1 15 Figure 4 1 16 Figure 4 1 17 Figure 4 2 1 Figure 4 2 2 Figure 4 2 3 Figure 4 2 4 Figure 4 2 5 Figure 4 2 6 Figure 4 2 7 Figure 4 2 8 Figure 4 2 9 Figure 4 2 10 Figure 4 2 11 Figure 4 2 12 Figure 4 2 13 Figure 4 2 14 Figure 4 2 15 Figure 4 2 16 Figure 4 2 17 Figure 4 2 18 Figure 4 2 19 Figure 4 2 20 Figure 4 4 1 Figure 5 3 1 Figure 5 3 2 Figure 6 1 1 Figure 6 2 1 Figure 6 2 2 Figure 6 2 3 Figure 6 3 1 Figure 6 3 2 Figure 6 3 3 Figure 6 4 1 Figure 6 4 2 Figure 6 4 3 Figure 6 4 4 Figure 6 4 5 Figure 6 4 6 Time integration at LOOMS en ep tube sevo teer 4 63 Time integration at 350ms 2 nti e DR e e d E E De pope etos 4 63 Timeintegration at 400ms eerte me eee e ere tere trees 4 64 Time integration at 7
232. onstruction of the tropical cyclone and it is necessary for it to know the amount and vertical distribution of non thermal insulation heating which a precipitation process gives each low pressure Therefore a plan for TRMM follow on is proposed as GPM mainly in Japan and the United States Moreover the PR of TRMM is the first satellite loading rainfall observation radar in the world and many development elements are left as for the technical side as well Therefore a concept for the TRMM follow on has been planned since a prospect was made for the realization of the TRMM plan A concept for TRMM was planned in the NASA GSFC in 1986 At that time the reliability of the rainfall observation due to the microwave radiometer from the satellite wasn t satisfactory yet On the other hand it was aware of the significance of the rainfall of the tropical zone as a driving force for the atmosphere circulation and therefore a PR was made indispensable as a rainfall sensor boarded on satellite At present rainfall observation is made in a considerable accuracy by the microwave radiometer and the visibility and infrared radiometer as well The satellite observation data is combined with the ground rainfall measured value and so on and the rainfall distribution map of the world is being made at present The purpose of TRMM is a little different under such conditions since that the concept was shown At the beginning of mission it was the major purpose
233. orithm is invoked The files do not change with time except at new algorithm releases The files must therefore be stored at TSDIS permanently but there is not distribution requirement 4 37 Section4 OUTLINE OF THE TRMM PRODUCTS d Output files The outputs of 2A12 processing are listed in below Data Flag dataFlag Rain Flag rainFlag Surface Flag surfaceFlag Surface Rain mm h surfaceRain Convective Surface Rain mm h convectRain Confidence K confidence Cloud Liquid Water g m cldWater Precipitation Water g m precipWater Cloud Ice Water g m cldIce Precipitation Ice g m preciplce Latent Heating C h latentHeat The data flag indicates the quality of data and has the following values 0 Good data quality 9 Channel brightness temperature outside valid range 15 The neighboring 5 x 5 pixel array is incomplete due to edge or bad data quality 21 Surface type invalid 23 Date time invalid 25 Latitude or longitude invalid The Rain Flag indicates if rain is possible 0 Non raining 0 Rain is possible and not ambiguous rain may be zero or positive 0 Rain is possible but ambiguous rain may be zero or positive The Surface Flag indicates the type of surface and has the following values 0 Water 1 Land 2 Coast land and ocean is mixed 3 Others The Surface Rain 15 the instantaneous ra
234. ors has been almost investigated and the clutter may be removed by using the processing algorithms after Version 5 According to the above discussion TRMM data seems to be better quality than data from ground radars It is difficult to realize higher accuracy than 1 dB by means of the technical calibration However 1 dB error of radar reflectivity causes 15 error of rain rate If the error is unintentional error reduction is possible by the average of many samples One side bias error must be reduced by validation In addition it has been confirmed that the received power of PR and ARC has decreased by amount of the increased propagation losses by the altitude rising from the result of the external validation experiment data using ARC after the TRMM s altitude change The received power coincides to the value calculated based on the present validation coefficient within the range of 0 5 dB and it has been confirmed that the present validation coefficient can be used also for the post boost data The purpose of TRMM is to measure absolute quantity of rain distribution in high accuracy So it is important to validate radar reflectivity by means of comparison with ground radar data rain measurement network data and so on For validation of radar reflectivity the following ground radars have been used Japanese ground radar such as meteorological radar at Ishigaki Island Rutherford Appleton Laboratory s ground radar placed in Sin
235. ower System Battery SOC Verification Every Orbit Communications System TDRS Tracking R amp RR 16 to 17 per Day 2 21 Section2 OUTLINE OF THE TRMM SATELLITE Once per Day and Subsequent to each Maneuver 1 Every month 1 Delta V Maneuver Initially Every 7 10 Days Every 2 Days near EOL 180 deg Yaw Maneuver Every 2 to 4 Weeks C amp DH Operations S C Stored Command Load Once per Day ACS and S C Processors Solid State Recorder Operations Close Data Set Recorder Playback Retransmissions Release Data Set S C Clock Checks C ications Slew Operations for TDRS XMTR Operations 2 Way XMTR Operations 1 way Doppler HGA Feathering Instrument Operations CERES Biaxial Mode su Every 3 Days CERES Short Scan Mode a a a Every SR amp SS While in Biaxial Mode CERES Max Scans ecw ele a aj Every SR amp SS While in Biaxial Mode CERES CrossTrack Mode mm 2 Days Every Third Day CERES External Calibrations m Every 2 Weeks VIRS Solar Calibrations e Every 1 3 Weeks PR External Calibrations cee Month PR Antenna Pattern Measurements gt a Every 6 Months 3 00 6 00 9 00 12 00 15 00 18 00 21 00 24 00 UTC Figure 2 5 1 24 Hour Operations Profile 2 5 2 Instrument Operation The Science Operations Control Center SOCC will be the FOT s point of contact for instrument planning of the PR
236. parisons of TRMM PR and CAMPR data obtained from simultaneous observations provide a way to validate and evaluate the TRMM PR and its rain retrieval algorithms Figure 6 2 2 shows that the CAMPR observation gives higher spatial resolution and sensitivity and that you can find a good consistency between them 67 Section6 TRMM OPERATION STATUS RESULTS and FUTURE PLAN PR Z Factor 1998 May 26 0222 0223 GAMPR 2 Factor nadir 0 a n 55 Figure 6 2 2 Example of Such a Simultaneous Observation by TRMM PR and CAMPR Upper TRMM PR Data Lower CAMPR Data The synchronous observation of PR and the ground radar was done at the site in Melbourne Florida on March 9 1998 Figure 6 2 3 is the result of synchronous observation and shows radar reflectivity distribution at fixed height of 3 km The data indicates better consistency on the radar reflectivity distribution pattern but the absolute value of PR reflectivity is 2 dB higher than that of the ground radar This differential is caused by that the PR sampling volume size and location do not coincide thoroughly with those of the ground radar b Melbourne Radar at 3 km 28 5 42dBZ 37 982 28 Latitude deg Latitude deg N 27 B1 5 81 80 5 80 79 5 82 81 5 81 80 5 80 79 5 Longitude deg Longitude deg Figure 6 2 3 Distribution Pattern of Radar Reflectivity 2A25 Lef
237. pd uonedodo uonejidroodq uotstAOJd 1 0 EWI 9 9 T 305 VAY 305 IVMIJOS 19151891 sjonpoid VSVN 10 05 UONPIQIeD 9183105 05002 8 15 JOMUOS A AJOL 8015592014 urojsAs 18 Figure 3 2 2 Overall Structure of the TRMM PR Data Processing System TRMM DATA USERSHANDBOOK 2 Software Structure The TRMM precipitation radar data processing system is made up of the following seven types of software and the relationship between each software and the facility machine is shown in Figure 3 2 3 a Precipitation radar level 1 processing software b Processing control software c Level 1 amp 3 software d Calibration processing software e Verification control software f NASA Products register software g Operation planning software PR Level 1 processing software Processing control software Processing facility Level 1 amp 3 software TRMM precipitation radar data processing Calibration software Verification control software Verification facility NASA Products register software Operation planning software Precipitation radar operation planning facility Figure 3 2 3 Software Structure of the TRMM PR Data Processing System 3 Operational Configuration Software configuration and flow of data are shown in Figure 3 2 4 for the system operations
238. pecification the FOT of TRMM made decision to carry out attitude control using the Kalman filter which uses the IRU the DSS and TAM Satellite attitude for post orbit boost was verified using the data of the distance between the satellites and earth surface in the scanning edge of PR As the result fluctuation of the roll angle which is not seen in the telemetry data of satellite altitude was found This fluctuation is changing with time This problem was caused by weight parameter of Kalman filter and fluctuation band of satellite attitude is mostly improved after modification of the filter on November 28 2001 This fluctuation of attitude leads to an error on estimation of sea surface temperature from TMI observation and on estimation of NRSC from PR observation However these errors were solved with revision of Geolocation Toolkit and their revised data have been outputted for products after February 2002 To reprocess for algorithm version 6 all of data are revised 2 57 TRMM DATA USERSHANDBOOK 3 OUTLINE OF THE GROUND SYSTEMS This section introduces the outline of the total ground system of Japan and US for TRMM mission operations 3 1 TRMM Total Ground System The configuration of the TRMM ground systems of NASA and JAXA is shown in The operation of the TRMM satellite will be done via TDRS by NASA GSFC Telemetry data and mission data will be acquired at the White Sands station in US using TDRS as well as commandi
239. pitation Radar Data Processing System eese tenente nne 3 2 3 21 iProcessinpFacilityss E V Ive OBVIOS ORENSE RS 3 6 3 22 Verification facility e E ET e dt 3 7 3 2 5 Operation Planning Facility dH eee ei er ei TIRE EIS 3 7 3 2 4 Precipitation Radar Calibrator esses eee ennemis 3 8 3 3 Earth Observation Data and Information eese netten netten nenne 3 10 3 3 1 Data Distribution and Management eene enne nente nennen 3 11 3 3 2 Data Generation System ririri aisean EEEE EET Ei REEE EEEE EDE AEE EERTE ATEREA 3 13 3 3 3 Schedule Management Systems orcii ee a e i oe E eE E E a eA AS Ee Ea E 3 13 3 3 4 Catalogue Data Distribution 3 14 3 3 5 On Line Information SysteM TNE EENE EAT TEE EA 3 14 3 3 6 Information Service System c cccecccesccesssesssessceseceeceseceseceseceseceseceseceaeceaeseaaeceaeceaeseaeseaeseaeenaeeeas 3 14 3 4 INASAcGrOUld SysteWL ie REG BO 3 15 3 4 1 Mission Operation Center MQQC isses eene nennen enne entente entrent rennen nennt 3 17 3 4 2 NASA Communications ea i read ee Hte oo ee ia chan oer a e 3 17 3 4 3 Network Control Center eese 3 18 3 44 Flight Dynamics Facility 3 16 3 4 5 Sensor Data Processing Facility SDPF esses nne
240. r TAM Three Axis Magnetometer TCP Transmission Control Protocol TCS Thermal Control Subsystem TDA Transmit Drive Amplifier TDRS Tracking and Data Relay Satellite NASA TK Toolkit TMI TRMM Microwave Imager TOA Top of the Earth s Atmosphere TRMM Tropical Rainfall Measuring Mission TRS Transmitter Receiver Subsystem TSDIS TRMM Science Data and Information System NASA TSM Telemetry and Statics Monitoring TSU TSDIS Science Users TX Transmitter U UPD User Performance Data UPS User Planning System URL Universal Resource Locator UTC Universal Time Coordinate UTCF Universal Time Correlation Factor VCID Virtual Channel Identification VIRS Visible and Infrared Scanner VIS Visible VSWR Voltage Standing Wave Ratio 1 3 TRMM DATA USERS HANDBOOK Appendix 2 RELATED INFORMATION 1 Reference Documents The titles provider and contents of the reference documents are shown below a EOIS User Interface Software Users Manual Prepared by JAXA EOC Contents Utilization manual of the EOIS User I F Software EUS which is a client software of the EOIS of JAXA EOC b TRMM Earth View Second Edition Prepared by JAXA EORC Contents Brochure which shows many results of TRMM observation and its data utilization by using a lot of picture This brochure can be obtained from NASDA EORC home page and the CD ROM is also available c Tropical Rainfall Measuring Mission P
241. r Orbit Boost 2 56 Table 3 3 1 Subsystems of ettet tee atte ee oU o ee d e tetas 3 11 Table 3 3 2 Function oEDDMS tor t esee 3 12 Table 4 1 The definition of the TRMM 4 1 Table4 1 T FRMM Products e de das ides e RO RE RE ERE EE ER 4 2 Table 4 1 2 PMEProduets iret rrt t rere Pete ee e era 4 35 Table 4 1 3 VIRS Product si te theme omen mede er edente 4 41 Table 4 1 4 COMB Products tette d i m T P ette 4 42 4 159 CERES Data ede 4 50 Table 4 1 6 Outline of LIS Data Products gt 4 57 Table4 I 7 Resultant Area Data eene er t etr ele 4 65 Lable 4 1 8 Res ltant Flash Data e e Ee t E 4 65 Fable 4 1 9 Resultant Group Data ntes pee ye ete edi deve gode ad dede 4 65 Table 4 1 10 Function Structure of LIS Data Processing Software sess 4 66 Table 4 2 1 Grdstructure eee tee m oer t e reds 4 71 Table 4 2 2 TIMEEQquatiohS 5 peteret eteedeeieie 4 T Table 4 2 3 OFFSET Values ui cerit eti eere ei eee eria e redd bt e Ue Tee dehet 4 78 Table4 2 4 Error Fields ette tere 4 78 4 3 1 Fool Kit Categories 4 92 Table 4 3 2 Module 4 96 Table54 l EOIS Data Services zz isst 5 1 Table 5 2 1 TRMM inventory information managed and provi
242. rameter is used in describing these formats nscan the number of scans within one granule 18026 on average Figure 4 2 16 shows the structure of the 1B01 product in terms of the component objects and their sizes The 1B01 product is stored as a swath structure Section4 OUTLINE OF THE TRMM PRODUCTS BCS Care LO DUE byte Product Specific Metadata 10 000 byte 5wathisiructure bey bes Data Senn Time Table Granule Gieolacanian 3 bes Araye 2x dpl nascan Svah Data Navigation ER bytes Table nscan Solar Cal macam Calibration Counts i Aray x Ik 3x nan M Temperature Counts Array a necu Local Dircetion ATAY ia x 2 iscat Aray 5 x 261 x mscon Figure 4 2 16 Data Format Structure for 1B01 4 2 44 COMB 1 2 31 Rain Profile The 2B31 is stored as Swath Structure in HDF Figure 4 2 17 shows the structure of the 2B31 product in terms of the component objects and their sizes The following sizing parameter is used in describing this format nray 49 the number of rays within one PR scan line nscan 9150 the number of PR scans within one granule when orbit altitude is 350 km on average nscan 9250 the number of PR scans within one granule when orbit altitude 15 402 5 km on average ngeo 2 the number of geolocation data Nradarrange 80 the number of radar range gates up to about 20 km from the earth ellipsoid 13 the numb
243. rating on data from one data model As a result of HDF s tool set modularity you need only familiarize yourself with the data model specific to your needs Each data model 1 shown in the following a The 8 bit raster model Stores and retrieves 8 bit raster images their dimensions and pallets b The palette model Stores and retrieves 8 bit palettes outside the 8 bit raster model c The 24 bit raster model Stores and retrieves 24 bit images and their dimensions d The scientific data model Stores and retrieves multi dimensional arrays of integer or floating point numbers their dimensions number type and attributes e Theannotation model Stores and retrieves the text strings used to describe a file or any of the data elements it contains f The virtual data model Stores and retrieves multi variate data stored as records in a table In addition to these six data models a vgroup is designed to associate related objects Section4 OUTLINE OF THE TRMM PRODUCTS HDF data models are designed to support only those data elements which are applicable to the group as a whole In other words data models are limited to data elements which make sense in the context of the group The 24 bit raster model for example will not support palettes or three dimensional arrays because neither of these are necessary for 24 bit imaging operations p Palette STE Scientific Data arrays Ala com 2
244. reception it inputs the RF signals from the 16 system divider combiner 2 and output them to the frequency converter IF assembly after combining them 3 Possesses a circulator used to isolate the input output signals to the frequency converter IF assembly as well as a signal dividing combining hybrid 4 To correspond to the two frequency converter IF assemblies which include the redundant systems it is provided with two input output terminals into the frequency converter IF assemblies for both transmission and reception 4 Divider Combiner 2 a Structure Divider combiner 2 DIV COMB2 is made up of hybrid 5 bit digital phase shifter PHS and isolator ISO circulator CIR 2 45 Section2 OUTLINE OF THE TRMM SATELLITE b Function 1 During transmission it inputs the RF transmission pulse from divider combiner 1 then branches it into 8 signals and outputs them to SSPA after adjusting them to required phases using a digital phase shifter 2 During reception it inputs the RF signals from 8 system LNAs adjusts them to required phase volume and outputs them to divider combiner 1 after combining them 3 Possesses a circulator in SSPA LNA output side which is used for isolating the input output signals 4 Enables control of the digital phase shifter using control signals 5 Power Supply a Structure Power supply RF system is made up of the primary and the redundant system and are mutually connected
245. rence prevention 2 37 Section2 OUTLINE OF THE TRMM SATELLITE g Safety Mode This mode is the state when non essential bus power necessary to operate the precipitation radar is not supplied from the TRMM observatory and essential bus power is supplied only to the survival heater of the radar The precipitation radar was set in this mode before the TRMM observatory was launched and was maintained in it from the launching of the satellite to the initial stage Launch mode IOA mode The precipitation radar will shift to this mode when there is an abnormality Safe hold mode Low Power mode in the TRMM observatory Apart from the above the radar would have been set in this mode had an abnormality occurred GSTDN mode during launching of the TRMM observatory or during its initial stage Interrelationship between the operation modes are shown in Figure 2 6 4 Internal calibratio External Cal Limited scan External Calibration fixed Beam Health Check Transition by command Transition by command or signal from spacecraft Transition by power source from spacecraft command State of RF Emission State of non RF Emission Figure 2 6 4 Transition of PR Operation Modes 2 6 3 Performance The main performance characteristics of the precipitation radar are 2 38 TRMM DATA USERSHANDBOOK Frequency 13 796 GHz f1 and 13 802 GHz f2 2 frequencies agility 2 Tran
246. repared by JAXA EORC Contents Brochure of the TRMM program d Tropical Rainfall Measuring Mission TRMM Precipitation Radar Algorithm Instruction Manual Version 6 January 11 2005 Prepared by TRMM PR team Contents Algorithm description of PR e Interface Control Specification Between the Tropical Rainfall Measuring Mission Science Data and Information System TSDIS and the TSDIS Science User TSU TSDIS P907 Volume 1 Algorithm Software Development and Delivery Release 5 01 June 2 2000 f Interface Control Specification Between the Tropical Rainfall Measuring Mission Science Data and Information System TSDIS and the TSDIS Science User TSU TSDIS P907 Volume 3 File Specification for TRMM Products Level 1 Release 6 02 June 23 2005 g Interface Control Specification Between the Tropical Rainfall Measuring Mission Science Data and Information System TSDIS and the TSDIS Science User TSU TSDIS P907 Volume 4 File Specification for TRMM Products Level 2 and 3 Release 6 06 A2 1 Appendix 2 RELATED INFORMATION February 8 2006 h TSDIS Level 1 Software Design Specification Volume 2 Version 5 July 15 1998 i Clouds and the Earth s Radiant Energy System CERES Algorithm Theoretical Basis Document Release 2 2 June 2 1997 j Algorithm Theoretical Basis Document ATBD for the Lightning Imaging Sensor LIS February 1 2000 K HDF EOS Library User s Guide for the
247. ring all mission modes There are two types of components included in the THM design passive and active components Passive components include thermal blankets louvers thermal coatings and some temperature sensors Active components include heater elements heat pipes thermostats and Solid State Temperature Controllers 2 1 7 Reaction Control Subsystem RCS The RCS provides the propulsion capability required for orbit maintenance attitude control during orbit maneuvers and the safe end of life ocean disposal The RCS also provides the capability to perform back up momentum wheel unloading and yaw maneuvers The implementation of either of these back up capabilities requires two or more ACS component failures and therefore no fuel has been budgeted for these capabilities The RCS consists of twelve Rocket Engine Modules REMs five Fill and Drain Valves Pressure Transducers Regulators Propellant Control Module PCM Pressure Transducers Propellant and Propulsion tanks Figure 2 1 7 provides a functional block diagram of the RCS 2 7 Section2 OUTLINE OF THE TRMM SATELLITE Fill and Drain Valves 5 Pressurant Tank 4 Pressure Transducer high lt Pyrotechnic Valve 48 Redundant Regulator Propellant Tank 1 Tank forward Module Propellant Tanks 2 Pressure Transducers 2 precision Propellant Control Module Filters 2 Tank Valve lt Isol
248. ro Order Mites Array slat x nk x nca x ahi x adhah IB 3 bates Array ala x olen x nca x hd x nrhrsh lk POZAS 4 bates Array ala x nln x ncaa x mh x nrhrsli Planetanetirs ke Oender buses HB Fit 4 bytes FnzAz25 up Array ala x x nhi x 3 x msihrsh Array mar x x x 3 x Array ml x x x 3 x a Mh Onder Fl 4bwnes Array ala x x nh x mbrsh R lzabaliry HB Fit 3 buses Relzbaliry 2425 Fil 4 Array ala x nbn x nht ox ninh Array ala x nh x nh ox ramMleamsTH thates ala x len x nh Figure 4 2 12 Data Format Structure for 3A26 4 2 4 2 TMI The following parameters are used in describing format of TMI products lt Level 1 amp Level 2 gt npixel 208 the number of high resolution pixels within one scan line nscan 2991 the number of scans within one granule on average ngeo 2 the number of geolocation data nlayer 14 the number of profiling layers within one pixel 484 TRMM DATA USERSHANDBOOK lt Level 3 gt nlat 16 the number of 5 grid intervals of latitude from 40 N to 40 S nlon 72 the number of 5 grid intervals of longitude from 180 W to 180 E 1 1 Brightness Temperatures The 1 11 is stored a Swath Structure in HDF Figure 4 2 13 shows the structure of the 1B11 product in terms of the component objec
249. ropopause and TOA The major steps in the SARB algorithm for each CERES FOV are 1 Input surface data albedo emissivity 2 Input meteorological data T q O 3 aerosol 3 Input imager cloud properties matched to CERES FOV s 4 Use radiative model to calculate radiative fluxes from observed properties 452 TRMM DATA USERSHANDBOOK 5 Adjust surface and atmospheric parameters cloud perceptible water to get consistency with CERES observed TOA SW and LW fluxes constrain parameters to achieve consistency with subsystem 4 6 surface flux estimates if validation studies show these surface fluxes to be more accurate than radiative model computations of surface fluxes 6 Save final flux calculations initial TOA discrepancies and surface atmosphere property adjustments along with original surface and cloud properties While global TOA fluxes have been estimated from satellites for more than 20 years credible global estimates for surface and in atmosphere fluxes have only been produced globally in the last few years Key outstanding issues for SARB calculations include Cloud layer overlap see ATBD subsystem 5 0 Effect of cloud inhomogeneity 3 D cloud effects Potential enhanced cloud absorption Land surface bi directional reflection functions emissivity and surface skin temperature see ATBD subsystem 5 0 For Release 2 SARB will use plane parallel radiative model calculations and will treat cloud inhom
250. rowave scattering caused by these ice crystals In this way the rainfall process in the clouds and the characteristics of rainfall will be revealed by the simultaneous measurement by these three sensors TMI and VIRS usually used for presumption of rainfall are boarded on TRMM with PR and these three sensors can acquire rainfall data simultaneously in different way Before TRMM it was too difficult to adjust rainfall measurement results from these sensors So it is expected that 6 13 Section6 TRMM OPERATION STATUS RESULTS and FUTURE PLAN the data processing algorithm of each sensors will be improved by using TRMM data m O Tun LXI ACE Lu a fewer pe 1 00 Fig YRS AGB color composite Fig PP Horiznnial Cross Section of Arin al zim Hegh n Nx m HX m wn am IUSTANCE Brij 4 Wi M 35 1 E an Harsa perii coo um Wr GE 214 20 20 TOU Ad EB LEO by TRA V POL Brighimess Tempenture Fip4 Yei Cross Figure 6 4 3 Rainfall Observation Result from VIRS TMI PR 3 Soil Wetness Estimated from PR Backscattering data from the PR includes not only the information of soil wetness but also vegetation amount and land surface roughness Using the information of NDVI from visible and infrared sensors and the theory of microwave scattering the effects from vegetation and roughn
251. rtical axis of each figure indicates Range Bin Number which corresponds to relative distance from satellite 1 Range Bin 250 m PR 1B21 output includes received power PR 1C21 output includes non validated radar reflectivity PR 2A25 output includes rain rate profile and radar reflectivity that is corrected using rain attenuation value lower figure shows rain rate profile Like this received power radar reflectivity and rain profile are calculated successively for each normalized radar surface cross section within IFOV 6 9 Section6 TRMM OPERATION STATUS RESULTS and FUTURE PLAN LET Hm Sz amacTrdiuk o uo moo a o Es Fal CEETZTERI Tib n m E 1229 Eine Lag ie Figure 6 3 1 Example of PR Output Product 1B21 1C21 and 2A25 3D Rainfall Structure over Argentine 2 Output of 2A23 Figure 6 3 2 is an example of PR 2A23 product and it is classified by rain type which include stratiform convective and so on The figure shows observation result of Typhoon No 28 over sea in east of Philippines on December 19 1997 The scene size is 220 km cross track x 630 km along track Bb cocvetive gt Dbbera Hargai Figure 6 3 2 Example of PR Output Product 2A23 6 10 TRMM DATA USERS HANDBOOK 3 TRMM
252. s been established as one orbit Thus all data from the LIS is stored and summarized at the orbit granule However the beginning and end times of the LIS TRMM DATA USERSHANDBOOK orbit granule differ from the TRMM defined orbit Since dividing the LIS data at the equatorial crossing would often split storms the LIS orbit granule is defined to begin and end at the latitude of the southernmost part of the orbital path This location is often away from lightning producing tropical convection This should lessen the probability that users will have to acquire more than one orbit to study specific lightning systems An orbit will include every area with latitudes contained within the geographic boundaries of the orbit flashes groups and events associated each area in an orbit will be kept with the orbit regardless of where they were located Background images occurring between the start and stop location of the orbit will also be kept with the orbit An orbit is identified as 11807 Since orbits will have a geographic start and stop at the southernmost location of the orbit it is possible for flashes groups and events to be on the opposite side of the orbit boundary from the parent areas This will occur if the areas were active at the time of the orbit boundary crossing Since all of the LIS lightning data is associated with the parent area all child data flashes groups and events will be kept in the orbit with the parent area
253. s in elevation angle thereby providing angular sampling of the entire hemisphere of radiation The RAP scanner when combined with cloud imager classification of cloud and surface types will be used to provide improvements over the ERBE ATBD subsystem 4 5 4 50 TRMM DATA USERSHANDBOOK Figure 4 1 11 The scan pattern of two CERES scanners on EOS AM and EOS PM spacecraft 2 Subsystem 2 ERBE Like Inversion to Instantaneous TOA Fluxes The ERBE like inversion subsystem converts filtered CERES radiance measurements to instantaneous radiative flux estimates at the TOA for each CERES field of view The basis for this subsystem is the ERBE Data Management System which produced TOA fluxes from the ERBE scanning radiometers onboard the ERBS Earth Radiation Budget Satellite NOAA 9 and NOAA 10 satellites over a 5 year period from November 1984 to February 1990 Barkstrom 1984 Barkstrom and Smith 1986 The ERBE Inversion Subsystem is a mature set of algorithms that has been well documented and tested The strategy for the CERES products is to process the data through the same algorithms as those used by ERBE with only minimal changes such as those necessary to adapt to the CERES instrument characteristics 3 Subsystem 3 ERBE Like Averaging to Monthly TOA This subsystem temporally interpolates the instantaneous CERES flux estimates to compute ERBE like averages of TOA radiative parameters CERES observations
254. scientists at least four weeks in advance to allow for coordination with other observatory activities and incorporation into the Daily Activity Plan DAP The FOT will coordinate the 2 23 Section2 OUTLINE OF THE TRMM SATELLITE activity with all other instrument and spacecraft activities The time and beam angle necessary for the measurement will be provided by the JAXA EOC via the SOCC The necessary commands will be placed into the daily spacecraft command load in order to perform the Antenna Pattern Measurement During the planning process JAXA EOC will receive verification of PR activities via the timeline report and after load generation via the Integrated Print report For planning of both the external calibration and the antenna pattern measurements JAXA EOC will request two time windows The second window will only be scheduled as a backup in case of poor weather conditions during the first window opportunity VIRS and TMI activities will be scheduled by the Instrument Scientists using the appropriate MOC provided planning aids Note Planning aids will be distributed to the Instrument Scientists via the SOCC VIRS solar calibrations will be scheduled according to when the Sun is predicted to be in the field of view of the VIRS solar calibration port The TMI instrument will not have any routine activity requests since TMI operates without interruption throughout the mission No nominal commands will be required Any requested
255. settling time The calibration itself should only take approximately 5 minutes at which time the spacecraft will be yawed back to its nominal orientation X forward Before the Cross track Antenna Pattern Measurement is initiated the PR will be commanded to the external calibration fixed beam mode in which a beam number is also commanded to the instrument The beam number will correspond to a specific angle that JAXA EOC will use to point the ARC The Cross track Antenna Pattern Measurement Calibration timeline is shown in Figure 2 5 3 TRMM DATA USERSHANDBOOK Table 2 5 3 PR Operational Modes will be the normal operating mode of the instrument During this mode PR instrument performs normal rain echo measurements with a 17 scanning range This mode will provide an on orbit calibration of the PR instrument by the Active Radar Calibrator Calibration on the ground Limited scan or Fixed beam submodes may be used in either the spacecraft nominal configuration or the 90 yaw configuration Limited scan scanning for 7 beam directions centered at a selected angle bin Fixed beam Beam is fixed to a selected angle bin No scanning is performed mode will provide an on orbit calibration about the input output characteristics of LOGAMP Cali alibration with internal loop signal During this mode no RF signal is radiated from the antenna and science Observation will not occur Health Check This mode is for ch
256. smission within 2 x 10 3 years and 2 months frequency stability 3 Occupied bandwidth within 14 MHz 4 Spurious 50 dBc or less at antenna subsystem input output port 5 Range resolution 250 m or less normal at 6 dB width of reception filter output pulse 6 Horizontal resolution 4 34 0 12 km or less at nadir with a physical altitude of 350 km Horizontal resolution on the ground where the normal is 6 dB width of the transmit receive round trip antenna pattern 7 Minimum radar echo 111 dBm Reception level Smin The value at the interface point with the antenna subsystem It is a reception level where S N for each pulse becomes 0 dB Antenna input noise temperature is assumed to be 290 K 8 Minimum measurable 0 5 mm h S N per pulse 0 dB at the peak of rain area rainfall intensity 9 Scan width a During observation 215 km or more Between centers of the width footprint at the mode surface when geographical altitude is at 350 km 10 Scan angle interval and the number of scan angle bins within each scan a During observation Scan angle interval 2 scan angle bins about 0 71 degree mode Number of scan angle bins 49 including nadir 11 Scan cycle a During observation 0 6 seconds or less mode 12 Antenna orientation fix During the external calibration mode it is possible to fix the antenna beam direction at the scan angle specified within the scan angle bins in addition to antenna scan provid
257. solution To obtain the requisite calendar month average of adjusted merged IR data 3B43 averages the adjusted merged IR pentads that span the calendar month of interest Also prior to combination with the SSM I adjusted merged IR and rain gauge data the monthly average unclipped TMI data is converted calibrated to TRMM Combined Instrument TCI data using the TMI TCI calibration parameters from Product 3B31 After the preprocessing is complete the four independent precipitation fields are merged together to form the best estimate precipitation rate and RMS precipitation error estimates b Input Data of 3B43 Processing For 3B43 processing 1B01 2A12 and COMB 3B31 and Merged IR data 3444 are input Additionally GPI is used to convert VIRS radiance to precipitation rate c Output Data of 3B43 Processing The outputs of 3B43 processing are listed below Precipitation mm This is the best precipitation estimate at each 0 25 x 0 25 grid precipitate Relative Error This is the error included in precipitation estimate at each 0 25 x relError 0 25 grid d Relationship with Other Algorithms 3B43 is the final product and is not input to any other algorithms 4 1 5 CERES CERES data products and their algorithm are explained hereafter 4 1 5 1 Product Definition The simplest way to understand the structure of the CERES data analysis algorithms is to Section4 OUTLINE OF THE TRMM PRODUCTS examine
258. ssigned to two new groups e for 11 and f for 12 The two new groups are less than 330 ms 50 ms from the time of the last group of flash B and are within 5 5 km adjacent of the parts of flash B so the two groups are assigned to flash B and area Time 400 ms Event Croup Flash Area gt E to ee Pe il T P d 8 p a a P i E B7 107 E b 12 EEG Figure 4 1 16 Time integration at 400115 e Time 700 ms The last time with events for this example is shown in Figure 4 1 17 At this time integration 700 ms after the first events and 300 ms after the last events there are two new events 13 14 The events are not adjacent so they are assigned to two new groups g for 13 and h for 14 Group g overlaps the parts of flash A however it has now been 350 ms greater than 330 ms since the last group associated with flash A Therefore group g is assigned to a new flash C Since flash C overlaps the parts of area and since there is no time limit for areas flash C 1 assigned to area Group is not within 5 5 km of any current flash so it is assigned another new flash D Flash D is also not within 16 5 km of any currently active area so it is assigned another new area y TRMM DATA USERSHANDBOOK Tune 7D ms Event Group Flash Area 1 4 n 07 t 7 n cu 5 ue p 27 m T n a un f rae prd s 9 E T e DUC o7 NO yf
259. stem Parameters ise ie SERO UN ERR 2 14 2 2 4 Clouds and the Earth s Radiant Energy System 2 15 2 2 MISSION QVerviIew 3 ei edo eo Ht d 2 15 224 2 System 2 16 2 2 5 Lightning Imaging Sensor LIS esses eene ener nennen entente entente 2 16 2 201 CMISSIOROVEEVIOW e e fen 2 16 2 2 5 2 System Parameters a i aceti dite corte 2 17 2 3 Outline of the Orbitz ode s 2 18 2 4 Mission Operation Phase of isses ener 2 19 2 5 Spacecraft and Instrument Operation esses eene nennen nnne ethernet enne 2 21 2 901 SpacecraftOperation ee eH TS TERT NH IR ESTNE RH 2 21 2 5 2 Instrument Operation uriini o EE VU Is vec Ee Pe Yee PO Oe asy ee NO WC FERE BENE ue ege 2 22 2 9 2 d PR art RD REOR RD 2 26 DD QD EME s tiec eec ec e e e re e Hi e e e de 2 27 2 5 2 3 VARS see E REN RU FEIER 2 27 2 9 2 4 CERES estie dtes deti d dtes CEE A 2 29 2 9 2 5 UEM e Y BRA ORNA E BH I IRA BER RA IRI 2 31 2 6 PR Detailed eese nennen ener entes enne nentes 2 32 2 6 1 Elements and Appearance eee tnt nee 2 32 20 2 sFUNCTIONS ico ERN BERE ERE ER ERU RE UR RR E RE 2 35 2 16 32 IPerformancesss tne Rie ele e cd taies eed a aaa bl
260. stic point of TRMM follow on mission so it is indispensable It is a major purpose with GPM to observe a rainfall to the high latitude stage as well There are many weaker rainfalls in comparison with the tropical area in the middle latitude area Moreover snow and ice crystal also falls as a precipitation particle Therefore the capacity of the higher sensibility and the identification capacity of the precipitation grain should be necessary to the PR of TRMM follow on For the purpose two frequency radar is probably suitable The two frequency radar which is studied now is composed of a 14 GHz radar succeeding PR of TRMM and a 35 GHz radar to be developed newly The 14 GHz radar has a performance not less than PR of TRMM The 35 GHz radar is the same type of radar with PR and it is planned that the performance is improved more than TRMM and it has a 100 km scan width 6 20 TRMM DATA USERSHANDBOOK 1 ACRONYMS AND ABBREVIATIONS A DSS Digital Sun Sensor A D Analog to Digital E ACS Attitude Control Subsystem ECS EOSDIS Core System NASA ACE Attitude Control Electronics EOC Earth Observation Center JAXA ADEOS Advanced Earth Observing Satellite EOIS Earth Observation Data and Information ADM Angular Directional Model System JAXA AGO Santiago EORC Earth Observation Research Center ANT Antenna
261. t TRMM PR Data Right The Ground Radar Data at Melbourne Florida In summary distribution pattern of PR reflectivity coincides with the ground radar data very well but the absolute value of PR reflectivity is comparatively better than the data of the ground radar TRMM DATA USERS HANDBOOK because there is calibration problem for the ground radar in many cases Concerning the validation of absolute rainfall it is difficult to compare PR data with the ground radar data and the validation method is now under study It is suggested that rainfall measurement result from PR is usually underestimated from the observation results by other sensors than PR It was certified by the result of comparing between precipitation echo and sea surface mirror echo It is necessary to solve this problem and processing algorithm must be improved In future usual data analysis will be continued and it is planned to verify higher level products ex latent heat discharge profile etc 6 3 Example of PR Output Product 1 Output of 1B21 1C21 and 2A25 Figure 6 3 1 shows vertical structure of rainfall observed by PR on December 21 1997 from Uruguay to northern Argentine The upper panel is the example of 1B21 product the middle panel is 1C21 product and the lower panel is 2A25 product The horizontal axis of each figure indicates relative Scan Number which corresponds to distance along TRMM flight direction 1 scan 4 3 km The ve
262. t characteristic table calibration coefficients In this mode RF signal is not transmitted from the antenna d Analysis Mode This mode is used to check the operation state of LNA Specifically a beam is fixed to nadir and an echo from the sea surface 1 received in a LNA 1 element Received elements are sequentially switched and it is checked for each LNA of the 128 elements whether deference among peak value average echo value and average value at ground tests is within a limit 3 dB default An anomaly of LNA can be confirmed using display e Health Check Mode This is the first mode that the precipitation radar goes into after its power has been turned on It is also used for checking the health of the precipitation radar during the Engineering mode of the TRMM observatory This mode also checks whether the RAM ROM inside the SCDP is functioning correctly In this mode RF signal is not transmitted from the antenna This mode is the most secure mode and the precipitation radar is generally put back into this mode and put on standby should an abnormality occur f Standby Mode Used when resetting or changing the phase code used with the precipitation radar In this mode the set phase code can be checked by telemetry Also RF signal is not transmitted from the antenna in this mode Furthermore this mode is also used when stopping data transmission of precipitation radar for a short time for such purpose as interfe
263. t in possibly cluttered ranges 13 Rain possible but probably sidelobe clutter Some strong echoes above noise exist but they are most likely caused by sidelobe clutter Rain no rain determination is based on the algorithm of Dr Kumagai of NICT and the algorithm of side lobe clutter rejection was improved by Dr Iguchi of NICT g Primary test Limit check is carried out to the system noise value of science telemetry data as well as to the 49 Section4 OUTLINE OF THE TRMM PRODUCTS noise during log amp input termination Dynamic range check is also carried out when converting to reception level and the result is reflected in the Level 1B scan status h Output Data of 1B21 Processing The outputs of 1B21 processing are listed below The received power value and the transmission power value of the precipitation radar are calibrated periodically by a receiver calibration software and external calibration experiment and are meant to correspond to aged deterioration etc The values are also changed during calibration coefficient change Meta Data PR Calibration Coefficients PR CAL COEF Ray Header RAY HEADER Scan Time scan time Geolocation geolocation Scan Status pr scan status Navigation pr navigation Power powers System Noise dBm 100 systemNoise Metadata are defined as the inventory information which is commonly applied for all angle bins The metadata is divide
264. t to the ground system Lightning Background Format Converting The purpose of the conversion routine is to filter out and separate the lightning background and platform instrument health measurements into separate data streams Pixel Based Filtering The lightning data stream contains many non lightning artifacts The purpose of this routine is to remove these pixels TRMM to Native Ephemeris Format Converting The purpose of this routine 1 to convert the TRMM native format ephemeris into a stream of satellite locations and satellite orientation vectors Ephemeris Filtering The purpose of this routine 1 to identify and remove anomalous artifacts in the TRMM ephemeris Geo Locating Lightning background and ephemeris data is combined to produce lightning and background data projected to Earth coordinates Determining LIS Viewtime This routine computes view times of lightning observation for 0 5 x 0 5 latitude longitude grids within the field of view of LIS during an orbit Flash Clustering The routine first clusters the data to the flash level and then uses statistical information to filter the flash data Flash Based Filtering The purpose of this routine is to remove the data due to geolocation errors and to remove remained NLE Non Lightning Event Area Clustering In this routine the accepted flashes are then clustered into areas Area Based Filtering In this routine t
265. ted to specific users and general users through JAXA Earth Observation Data and Information System EOIS This kind of data processing is carried out in accordance with the operation plans drawn up by the operators 2 Major Functions The major functions of the processing facility are as follows a Management of the processing instructions b Record of level 0 data c Data processing PR level 1 data processing 1A21 1B21 1C21 PR higher level data processing 2A21 2A23 2A25 3A25 3A26 PR Browse data processing 1C21 2A25 TRMM DATA USERSHANDBOOK d Near realtime processing e Management of the medium f Management of the constant files g Making of daily and monthly reports 3 Execution of Processing Automation To record level 0 data all that is necessary is to start up the computer normally the main computer which will carry out the processing with data reception as the trigger Also the system will automatically carry out standard product processing one by one by registering the operations at the start of each day 3 2 2 Verification facility 1 Outline Apart from the observation mode in which precipitation data is continuously collected the precipitation radar has a special mode which is for the calibration of the radar itself From this special mode data external calibration mode internal calibration mode LNA analysis mode and standby mode are used to determine the three types o
266. tellite deployment Though there is a problem that sampling interval becomes long when it tries to observe high latitude as for the TRMM follow on there is an advantage that this problem can be avoided by many small satellites carrying microwave radiometers a Core Satellite Launch Date approx 2010 Design Life Time 3years 2 month aim 5 years Satellite Mass 3 2 tons class 6 19 Section6 TRMM OPERATION STATUS RESULTS and FUTURE PLAN e Orbit Attitude approx 400km Orbit Inclination approx 65degrees e Sensor DPR Microwave Imager others e DPR Japan provide Frequency 14 35 GHz Distance resolution 250 m Ku 250m 500m Ka Horizontal resolution 5 km Sensibility target less than 18 dBZ 14 GHz less than 12 dBZ 35 GHz Swath Width 245 km 14 GHz 120 km 35 GHz e Microwave Imager almost the same as Microwave Imager TMI on TRMM U S provide As an option we examine addition of high frequency zone 165 183GHz e Visibility and Infrared radiometer Lightning Sensor Desirable b Orbit The satellite altitude of the TRMM follow on is about 400 km which doesn t change very much from TRMM because of the constraints of PR observation from orbit Orbit inclination angle is about 65 degrees to ensure an observation of precipitation for the Temperate Zone and the Sub Frigid Zone c Sensor The core satellite of GPM carries PR and Microwave Imager PR is the major characteri
267. test Catalog Figure 4 1 5 Function structure of 1B21 processing 4 12 TRMM DATA USERSHANDBOOK Ran i Over Sarees Same Echo Greer Samos Mirari E cha Flag 1 Rarvhic ian of Han P of d li Minera cha Locum Valet and Acidi of ie eeniecat on rrierrreabnn CL cep eta Diran Ciuin d Gamere an Figure 4 1 6 Relationship between the functions of 1B21 processing j Algorithm Modification for Raising TRMM s Orbit Altitude The 1B21 algorithm has been modified corresponding to the raising of TRMM s orbit altitude The major change points are change of ranging parameters related to the boost and the correction of a beam mismatch as explained in section 2 7 Especially about latter it may cause an error of maximum about 0 5 dB on estimation of normalized radar surface cross section 2A21 but the error of rain echo is estimated less than 0 1 to 0 2 dB On the other hand the processing algorithms higher than level 2 have no modification for Project Version 5A 3 1C21 processing In 1C21 processing the dummy radar reflectivity factor Z factor Z4 including rain attenuation during a rainfall is calculated using the radar equation from the already calibrated received power value and noise level value calculated in the 1B21 processing Fundamental equations Radar equation
268. th the TRMM observatory for transfer of command data and telemetry data etc as well as for precipitation radar power supply and power supply on off Section2 OUTLINE OF THE TRMM SATELLITE Observatory c Satellite Altude3 0 km Flight Direction DEN Nunbercof Indepe ndent S amples aie 1 WIS gt 64 Atthe Top of Rain Area lt 0 5 mwih Reis H l km Honze al Resolution lt Approx 4 km Figure 2 6 3 Measurement Concept of Precipitation Radar on board TRMM Orbit altitude 350 km 2 Operation Mode See section 2 5 2 1 for operation mode of each component The operation mode of SCDP corresponds to the operation mode of precipitation radar The outline of operation modes of the precipitation radar is a Observation Mode It is a regular precipitation observation mode that uses 17 04 antenna beam scan 49 beams and the satellite operates in this mode most of the time during the normal stage To carry out calibration of observation data in this mode operation is carried out in the external and internal calibration modes described below at appropriate times Ground surface tracking 1 carried out in this mode b External Calibration Mode This mode is used mainly to carry out calibration of the precipitation radar using the ARC positioned on the ground When a difference is found on comparison between transmit receiv
269. the passive microwave and radar observations are made Data from the VIRS instrument is used in rain estimation algorithms based primarily on the passive and active microwave sensors The VIRS instrument possesses a radiative cooler a Solar Calibrator door an Earth Panel shield and a Solar Panel shield The Earth panel shield is deployed to block the Earth s reflection and the Solar Panel shield prevents the sun from shining into the VIRS 2 2 3 2 System Parameters Figure 2 2 3 provides a graphical description of the VIRS instrument diagram Table 2 2 7 provides the VIRS system parameters and Table 2 2 8 provides the observation performance Figure 2 2 3 VIRS Instrument Diagram TRMM DATA USERSHANDBOOK Table 2 2 7 VIRS System Parameters Swath Width Scan angle 45 degrees 720 km at ground Scan Angle 360 degrees 98 4 rpm IFOV IFOV 6 02 mrad 2 11 km nadir Cassegrain optics The focal plane is the same for all bands Silicon Photo diode 0 63um HgCdTe 1 6 3 75 10 8 12 um Cooling temperature 117 Blackbody Solar diffusion board Deep space 50 kbps Daytime 49 kg 53 W For pre orbit boost See Section 2 7 5 about parameters of post orbit boost August 2001 Table 2 2 8 VIRS Observation Performance 1 Bandi Band Band 3 Band4 Band Clouds mappin Temperature at Objective PPNS between water and Vapor during daytime ice the top of clouds 0 Ce
270. the generation of a shock 4 57 Section4 OUTLINE OF THE TRMM PRODUCTS wave which rapidly decays into an acoustic wave 1 e thunder and electromagnetic radiation ranging from extremely low frequency ELF radio waves to x rays One of the strongest radiation regions is in the optical wavelengths with peak power typically between 100 to 1000 MW These optical emissions result from the dissociation excitation and subsequent recombination of atmospheric constituents as they respond to the sudden heating in the lightning channel It is important to stress that while the cloud significantly alters the temporal characteristics of the cloud top optical signals the cloud does not block these emissions When viewed from above the optical lightning signals appear as a diffuse light source radiating from the cloud top Measurements of the total optical energy radiated from the cloud top are in good agreement with ground based measurements of cloud to ground flashes and support the theory that the cloud acts like a conservative scatterer 1 e that most of the optical energy escapes the cloud LIS is a sensor which observes near IR spectrum created by lightning over the cloud LIS data products and their algorithm is explained hereafter 1 Definitions The basic science data product of LIS is lightning This product is comprised of several components including raw data level 1 A background images level 1 B events level 1 B
271. tion 8 grid elements for water and 4 for land The algorithm then determines the water vapor in the atmosphere which is related to the freezing height If the pixel is over water a simple regression type of algorithm is used to determine the integrated water vapor Results over water are smoothed across regions where no retrievals are possible due to rain Over land and mixed backgrounds topographic data along with a climatological database of water vapor contents and freezing heights are used to determine the likely local conditions The topographic data base with 4 km horizontal resolution and 200 m 4 36 TRMM DATA USERSHANDBOOK vertical resolution is expected to be available from TSDIS The climatological database will be supplied with the algorithm Based upon the freezing height the algorithm then screens pixels for clear sky conditions This is a simple polarization difference test If clear sky conditions are found the clearsky flag is set and no subsequent retrievals will be performed on this pixel For pixels which did not pass the clear sky test the algorithm next checks for cloudy but not raining conditions over ocean For this purpose the algorithm uses a small set of look up tables containing brightness temperature combinations for different cloudy conditions If the TB signature is compatible with clouds only then the cloud only flag is set for that pixel and no subsequent rainfall retrievals are performed The
272. tion Weight Total 3620 kg 3524 kg Fuel 890 kg Dry weight 2730 kg 2634 kg Data transmission Via TDRS 32Kbps Real Time 2Mbps Play Back Design life Mission instrument Precipitation Radar PR TRMM Microwave Imager TMI Visible and Infrared Scanner VIRS Clouds and the Earth s Radiant Energy System CERES Lightning Imaging Sensor LIS means the measured value Post orbit boost August 25 2001 The TRMM Observatory is comprised of a main body structure nine housekeeping subsystems and five science instruments This section provides a brief overview of the TRMM spacecraft subsystems The subsystems that comprise the TRMM spacecraft are as follows Command and Data Handling Subsystem C amp DH Attitude Control Subsystem ACS Electrical Subsystem ES Power Subsystem PWS Radio Frequency RF Communications Subsystem COMM Thermal Subsystem THM Reaction Control Subsystem RCS Deployables DEP Structure Subsystem STR mo Bo 0 2 1 Section2 OUTLINE OF THE TRMM SATELLITE Figure 2 1 1 provides a graphical description of the TRMM spacecraft Omni Directional Antenna 2 Solar Arrays 2 X Yeiodty vector 1 Figure 2 1 1 Spacecraft 2 1 1 Command and Data Handling Subsystem C amp DH The C amp DH provides redundant hardware and the software necessary to ingest validate and distribute commands various S C clocks needed to meet all ti
273. tion System TSDIS stored in EOSDIS through EOIS Catalog information is also called inventory information and comprises text data such as satellite names sensor names observation date and time observation area and data set names Table 5 2 1 TRMM inventory information managed and provided by EOIS Sensor Products PR J 1B21 1C21 2A21 2A23 2A25 3A25 3A26 1B11 2A12 VIRS 1801 2 31 3B31 3B42 3B43 Note Inventory information is provided only for full scene data 5 2 2 Image Catalog This service offers users Image catalog data of standard products produced by the TRMM Data System The image catalog data is the data that it visualizes browse data at the Browse data Distribution Subsystem EOIS This service is provided through EOIS The image catalog data is in JFIF JPEG File Interchange Format about 1000 x 1000 pixels size and produced for PR 1C21 and PR 2A25 See Table 5 2 2 Table 5 2 2 TRMM Image Catalog Data Description SE 1C21 refraction factor is indicated as color data which is 3 swath and centered TRMM ground footprint Horizontal resolution is 10 km x 10 km vertical 500 m Horizontal profile at 2 km Horizontal profile at 4 km Vertical profile at nadir 2A25 Indicate rain rate instead of radar refraction factor against above 53 Section5 EOIS DATA SERVICE 5 3 Data Distribution Standard data products of the TRMM Data Syst
274. to a wait file specified by the parameter file TRMM DATA USERSHANDBOOK If there is no science telemetry data or HK data that make up the Level 1A file as well as the wait file a file which only has the header record of data size 0 is created g QL data processing Even if the data specified by the parameter file is QL data it is possible to edit it to a Level 1A file Here a continuity check of the packets is carried out 1A21 Processing Function Figure 4 1 3 Function structure 1A21 processing QL Dana Continuity Check af the Packets PR HK Data ACS Anallary Data IPSDU Duta of the Packets Engmeering Value PR HK Conversz ca into Eogurecnug Val Limit Check bration C evel 1 Level 1A Level 1A are made from Science data and HK data for QL data Figure 4 1 4 Relationship between functions of 1A21 processing 2 1B21 processing In 1B21 processing the radar video signal digital count value is converted into a received power value as well as a noise level value in accordance with the algorithm calibration of received power based on temperature calibration as well as transfer function created based on the 4 7 Section4 OUTLINE OF THE TRMM PRODUCTS radiometric model of the precipitation radar Longitude and latitude information of ground surface is added to convert this value into radar reflectivity factor Z factor inc
275. ts and their sizes ECS Core HO DORT bytes Product Specific Metadata bytes bytta Data Sean Time nscan Granule g Cicolocution Amay 2 a 20 x nscan Scan Salis 2 Bytes Table anth Dain e Navigation 83 bytes Table nsean Calibratian 5 bytes nscari Calibration Counts 4 DGN xmnsc n E Satellite Local Zenish Angle 3 bytes Amay 12 x nean Law Resolution Channels 2 bytes 7 X 104 x nscan High Resolution Clanrsla 2 bytes Array 2 208 necan Figure 4 2 13 Data Format Structure for 1B11 2 2 12 Rain Profiling The 2A12 is stored as a Swath Structure in HDF Figure 4 2 14 shows the structure of the 2A12 product in terms of the component objects and sizes Section4 OUTLINE OF THE TRMM PRODUCTS ECS Core Metadata 10 000 bytes PS Metadata 10 000 bytes Swath Structure S000 bytes Data Granule Scan Time 9 bytes Table Geolocation 4 bytes Array Scan Status 23 bytes Table Navigation 88 bytes Table Data Flag byte Array Rain Flag byte Array Surface Flag 1 byte Array SwathData Surface Rain 1 bytes Array Convective Surface Rain tes Array Confidence 4 bytes Array Cloud Liquid Water 2 bytes Array b 2 bytes Array Precipitation Water Latent Heating 2 bytes Array Figure 4 2 14 Data Format Structure for 2A12 3
276. tted to Langley Research Center and Marshall Space Flight Center of NASA respectively However CERES has suspended operation after May 29th 2001 because it experienced problems with its power source PR Level 0 data is also transmitted to Japan and its higher level processing is performed at the JAXA Earth Observation Center EOC The higher level products Level 1 3 products produced by EOC or GSFC are distributed to users which include many scientists in the fields of climatology meteorology hydrology etc in Japan US and various other countries JAXA s Earth Observation Research Center EORC promotes scientific research using TRMM data and provides researchers with scientific datasets Table 1 4 2 Responsibilities of Japan and US related to data processing Primary Elements JAXA Japan NASA US Data Receiving Preprocessing of Data oo 0 Higher Level Processing o ooo Higher Level 9 Higher Level Processing of CERES o 9 Higher 1 4 TRMM DATA USERSHANDBOOK 2 OVERVIEW OF THE TRMM SPACECRAFT This chapter provides the overview of the TRMM spacecraft subsystems and its onboard instruments 2 1 Spacecraft Table 2 1 1 shows the main characteristics of the TRMM satellite Table 2 1 1 Main Characteristics of the TRMM Satellite At lift off 5 1 m length 3 7 m diameter In orbit 5 1 m length 14 6 m in paddle direc
277. ty and the precipitation radar operations planning facility set up at the TRMM operations division within the JAXA EOC and the ARC used in western Japan that is permanently set up at the JAXA EOC Each facility has an interface however are fundamentally independent There is no computer which manages all facilities collectively 32 TRMM DATA USERSHANDBOOK 2ursuag oway y Lori 42723534 UOTA T3850 WU T 23IO Budaa y esto 0 Wie npag Suome1ad 2219105 DOCS Aouaby uonexo dx aaedso rav uede yy v npn aneng 22 CE OV DPI Wa SAG UOMASSA Bye etido e 7 4 DATADHLL wasia pa waum 89659201 clos T d PINAL g uone zd PINAL UDTSIaAUD SIOS 8559201 qni uoggur gu ssy vie T waysAg uo uno gu SIO3 wasis Sussazarg WAAL poids wswH moe 7 2005590014 Bye eC wng ANAL 2018 9205 4380 uord uos DON Relationship between the TRMM PR Data Processing System Figure 3 2 1 and Foreign Organizations 33 Section3 OUTLINE OF THE GROUND SYSTEMS suoneziuea1o ugro OSL Adds DOW DOGS DD0S 514511 VSVN urejs g uoneunuojug uoneA1osqQ ues 3 05 Suruuve d Suruue
278. uation correction is made using the total path attenuation of land or sea surface echoes 2 2 1 2 System Parameters Figure 2 2 1 provides a graphical description of the PR instrument diagram Table 2 2 1 Table 2 2 2 and Table 2 2 3 provide system parameters Antenna subsystem parameters and TRMM DATA USERSHANDBOOK Transmitter Receiver subsystem parameters respectively Upper Panel Access Hole Antenna X Panel Center Panel ux Figure 2 2 1 PR Instrument Diagram Table 2 2 1 System Parameters Radar Type Active Phased array Radar Frequency 13 796 GHz and 13 802 GHz Two channel frequency agility 93 5 kbps For pre orbit boost See Section 2 7 about parameters of post orbit boost August 2001 Table 2 2 2 PR Antenna Subsystem Parameters 128 element slotted waveguide array antenna Table 2 2 3 PR Transmitter Receiver Subsystem Parameters Transmitter Type Solid State Power Amplifiers SSPA x 128 700 W Pulse Width 1 6 usx 2 ch Pulse Repetition Frequency PRF 2776 Hz Dynamic Range 81 5 dB 2 11 Section2 OUTLINE OF THE TRMM SATELLITE 2 2 3 TRMM Microwave Imager TMI 2 2 2 1 Mission Overview The TRMM Microwave Imager TMI is a Multi channel dual polarized passive microwave radiometer TMI utilizes nine channels with operating frequencies of 10 65 GHz 19 35 GHz 21 3 GHz 37 GHz and 85 5 GHz The TMI instrument provides data related to the rainfall
279. uiuc edu A2 3 Appendix 2 RELATED INFORMATION 3 Contact Points Contact point related to EOIS JAXA Earth Observation Center OrderDesk 1401 Numanoue Ohashi Hatoyama machi Hiki gun Saitama Japan 350 0302 TEL 81 49 298 1307 FAX 81 49 298 1398 E mail eusadmin eoc jaxa jp A2 4 TRMM DATA USERS HANDBOOK 1st Edition February 2001 2nd Edition February 2002 3rd Edition April 2006 Published by Earth Observation Center JAXA 1401 Numanoue Ohashi Hatoyama machi Hiki gun Saitama ken Japan
280. used to relate the radar echo receive power P with the radar reflectivity factor Z are shown below 4 13 Section4 OUTLINE OF THE TRMM PRODUCTS r C P Z r Z Radar Reflectivity Factor mm m dBZ 10x log Z P Rain Scattering Received Power Received Power System Noise Where C is a constant Radar Constant determined from transmission power wave length pulse width antenna gain and so on depending on the radar instrument characteristics and it is defined as the following equation a K BxG xG x6 xO XCXT 10 2192 d C P Radar Transmission Power W Transmission Antenna Gain dB G Receiving Antenna Gain dB and are approximated from the front gain value and using the following equation Go cos cos Beam Scan Angle rad Antenna Beam Width for Scan Direction3dB value rad 0 Antenna Beam Width for Cross Direction of Scan3dB value rad A Wave Length m e Df e 2 Dielectric Constant of Water K 0 9255 c Light Velocity 2 998 x 10 m s Propagation Range m t Pulse Width The function structure of 1C21 is shown in Figure 4 1 7 and the relationship between the processing functions is shown in Figure 4 1 8 The contents of the functions are explained below a Input data check The scan status of Level 1B product data is determined and if it is no rain data it
281. wo kinds of filtering are carried out The first 1 the Putback algorithm that returns previously rejected noise data to the output stream based on the recalculated noise rates The second type removes flashes from the data stream based on their very non lightning characteristics HDF File Creation The final step is to convert the data into HDF and write it to the two HDF files TRMM DATA USERSHANDBOOK 42 HDF Format 4 2 1 Outline of HDF The Hierarchical Data Format or HDF is a multi object file format for sharing scientific data in a distributed environment HDF was created at the National Center for Supercomputing Applications to serve the needs of diverse groups of scientists working on projects in many fields HDF was designed to address many requirements for storing scientific data including Support for the types of data and metadata commonly used by scientists Efficient storage of and access to large data sets Platform independence Extensibility for future enhancements and compatibility with other standard formats The HDF library currently supports six different data models where each data model represents a framework for accessing a different type of data and its associated information In a sense each data model can be thought of as a set of tools for customizing the contents an HDF file Although there is some overlap among tool sets in most cases each set of tools is limited to ope
282. wo science gathering modes will be interrupted periodically every two weeks to allow the instrument to perform solar and internal calibrations Internal calibrations are performed while the instrument is operating in either the Cross track or Biaxial Scan modes while performing a normal Earth scan profile CERES will be placed into Cross track mode via stored command that will initiate execution of an internal sequence When in Cross track mode the instrument will rotate only in elevation from horizon to horizon while being kept stationary at a fixed azimuth angle of 180 While operating in the Bi axial scan mode the azimuth gimbal will rotate back and forth normally between 90 and 270 while the elevation gimbal performs either a normal or short Earth scan profile Stored commands switch instrument operation between the normal and short Earth can profiles around sunrise and sunset to prevent the detectors from directly scanning the Sun In addition a command will be sent prior to each normal scan command to trigger a count of the scans during the normal scan profile If the number of scans reaches the number specified as the argument in the command CERES will be autonomously commanded to the short scan profile The normal azimuth gimbal rotation range of 90 to 270 will be in effect when values of the beta angle are less than 20 or greater than 20 When values of the beta angle are in the range between 20 and 20 the azimut

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