DLR GOME Product User Manual
Contents
1. DETAILED RESULTS ESC 0 1 2 N 1 O3 O3Temperature 0 1 2 N Figure 4 Organization of the GOME total column productsin the HDF5 structure 6 1 1 Description of Commonltems In the GEOLOCATION and TOTAL COLUMN groups all datasets have a set of attached attributes Theseare shown in the table below Attribute Name Data Type Description Title string Description of the dataset e g Ozone total column Unit string Unit of the values in the array e g DU FillValue same as dataset Value in the array if actual data value is missing ValueRangeMin same as dataset Minimum value in this dataset present only when applicable ValueRangeMax same as dataset Maximum value in this dataset present only when applicable 25 DLR GOME PUM 01 Iss Rev 2 C Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties Page 26 of 47 DLR 6 2 META_DATA Group The content of the META_DATA group is shown in the following tables Allowed values for parameters required by EECF and UMARF are consistent with requirements given in A2 and A3 Allowed values specified in italics indicate any value of the given type e g string meansthat the attribute can contain any string within the UMARF size limit2. sssssssse 41 7 7 Section 4 Indicator section un dio Era ceris tine ede PEE ERR EXE EHE EXER ERATES 42 7 8 Section 5 e End Sector kassiert obit ee cca Pneu P STK bep Cote 42 7 9 Trace G s Tables ue p ET eai pasar t ib 42 8 Usingthe Products usa 43 8 1 Confidence Flags and Ancillary Fields 43 8 2 Software and Tools for reading the ProductS cccesssseeeeeseeeeeeeeeeeeeeeeeeees 43 A Appendixes uae oesepis cse bn se CE E IRSE c Ei n EAD UR SINN IG ON De ERN E AED 44 ACTHBES Data Typs een 44 A 2 Traceability Matrix of HDF5 Metadatato EECF Parameters 45 A 3 Traceability Matrix of HDF5 Metadatato UMARF Parameters 46 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 7 of 47 19 February 2010 1 Introduction 1 1 Purposeand Scope DLR has been producing on an operational basis a range of total column trace gases and cloud products for GOME ERS 2 in the framework of ESA s D PAF project In the same way DLR producestotal column trace gasesand cloud products for GOME 2 MetOp in the framework of EUMETSAT s O3M SAF DLR hasa long experience in operational processing of GOME data and has developed a generic software for this purpose the Universal Processor for Uv vis Atmospheric Spectrometers UPAS A1 system This document is the user ma
3. E PD Allowed Values Allowed Values Attribute Name Data Type Description GOME ERS 2 GOME 2 Metop ArchiveFacility string Centre where the data is archived D PAF DLR OP O3DLR SatelliteID string Platform identifier mission and ERS 2 Mnn spacecraft StartOrbitNumber integer Orbit number at the start of sensing integer integer i e at the beginning of a dump InstrumentID string Instrument which acquired the product GOME GOME InstrumentMode VIEW MODES Specifies how many ground pixels VIEW MODES VIEW MODES structure were observed in the corresponding structure structure view modes SensingStartTime CCSDS ASCII UTC date and time at sensing start Date in CCSDS Date in CCSDS format ASCII format ASCII SensingEndTime CCSDS ASCII UTC date and time at sensing end Date in CCSDS Date in CCSDS format ASCII format ASCII ReceivingCentre string Centre that received the data KS GS DP ES ECF for EECF MS FBK FUC GCA PGS RUS SOC SVL UBI WAL WEC WIV ProcessingCentre string Centre that generated the data D PAFDLROP O3DLR ProcessingMode string Processing mode applied for generation N nominal N nominal of the product B backlogged B backlogged R reprocessed R reprocessed V validation V validation T near real time T near real time Revision string Global product revision required e g string string for reprocessing part of logical product ident
4. DatasetName Data Type Unit Description ESCCorrected float pixels mol cm SIant column density background corrected VCDO float pixels mol cm A priori vertical column density for the Pacific Region 140 160 W VCDCorrected float pixels mol cm Total vertical column density background corrected HCHO Flag integer pixels Flag indexing HCHO calculations see 6 7 6 on page 37 35 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 36 of 47 6 7 Detailed Flag Description 6 7 1 SurfaceConditionFlag Flag Value Description 0 1 Land Sea 1 2 Sun glint 2 4 Snow Ice These flags give additional information about the surface state of different pixels during retrieval 6 7 2 Quality_Flags Specified Valid Conditions c Description 9 03 NO2 BrO SO2 H20 HCHO OCIO O 1 Invalid total column retrieval retrieval retrieval retrieval retrieval retrieval retrieval If the retrieved total possible possible possible possible possible possible possible column is invalid it is and result replaced with the fill 2 20 value and this flag is set together with flags 1 and 2 1 2 Total column out of 75 700 0 5 10 0 1 5 10 10 0 100 kg lt 1 0 10 0 3 range DU mol cm mol cm 1000 DU m mol cm 100 1
5. AMFTotal Error float pixels windows Total AMF error QualityFlags integer pixels windows Quality flags for each pixel window see 6 7 2 The following subsections contain sub groups of the DETAILED RESULTS group which contain trace gas specific data 33 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 34 of 47 6 6 1 DETAILED RESULTS O3 Subgroup In the following table the number of atmospheric layers is denoted as layers in profile datasets DatasetName Data Type Unit Description ESCRingCorrected float pixels mol cm Retrieved effective slant column ring corrected for ozone O3Temperature float pixels K Fitted ozonetemperature RingCorrection float pixels Applied ring correction factor O3Profile float pixels layers DU A priori O profile usedin the retrieval of O layers 13 optional parameter TemperatureProfile float pixels layers K A priori temperature profile usedin the retrieval of O layers 13 optional parameter Iterative VCDNumberOf integer pixels Number of iterations for the iterative VCD algorithm Iterations 6 6 2 DETAILED RESULTS NO2 Subgroup DatasetName Data Type Unit Description AMFTropoClear float pixels l Tropospheric AMF for cloud free part
6. SubSatellitePointStartLat float Latitude of the sub satellite point at start of 90 90 acquisition For EPS products either the first measurement or first complete scan start point tbd at start of dataset SubSatellitePointStartLon float Longitude of the sub satellite point at start of 0 360 acquisition SubSatellitePointEndLat float Latitude of the sub satellite point at end of acquisition 90 90 SubSatellitePointEndLon float Longitude of the sub satellite point at end of 0 360 acquisition SatellitePosition POS VEC Position vectors X Y Z in km Vector in POS VEC Satellite Velocity POS VEC Velocity vector dx dt dy dt dz dt in km s Vector in POS VEC OrbitSemiMajorAxis float Semi major axis km float OrbitExcentricity float Excentricity float OrbitInclination float Inclination deg float OrbitRightAscOfAscNode float Right asc of asc node deg float OrbitArgumentOfPerigee float Argument of perigee deg float OrbitMeanAnomaly float Orbit mean anomaly deg float OrbitUTCDaysSince1950 integer UTC days since 1 1 1950 int OrbitMsSinceMidnight integer UTC ms since midnight int OrbitAscendingNodeCrossing CCSDS_ASCII Ascending node crossing UTC date and time CCSDS DateTime Date OrbitAscendingNodeLongitude float Ascending node longitude 180 180 UMARF notation OrbitActualDuration integer Orbit duration in minutes only counting valid pixels 0 60 SolarSpectraDate CCSDS_ASCII Date and time of the solar spectra CCSD
7. AMFTropoClear Error float pixels Error on Tropospheric AMF for cloud free part AMFTropoCloud float pixels l AMF for cloudy part 1 if clear sky AMFTropoCloud Error float pixels Error on AMF for cloudy part 1 if clear sky AMFTropo float pixels l Tropospheric AMF AMFTropo Error float pixels Error on tropospheric AMF VCDStrato float pixels mol cm Stratospheric vertical column density VCDStrato Error float pixels Error on stratospheric vertical column density VCDTropo float pixels mol cm Tropospheric vertical column density VCDTropo Error float pixels Error on tropospheric vertical column density VCDCorrected float pixels mol cr Total vertical column density corrected for tropospheric contribution VCDCorrected_Error float pixels Error on corrected total vertical column density NO2Tropo Flag integer pixels Flag indexing tropospheric NO2 calculations see 6 7 3 on page 37 34 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 35 of 47 19 February 2010 6 6 3 DETAILED_RESULTS SO2 Subgroup The SO2 algorithm internally calculates results for several assumed plume heights The number of plume heights is available in the field NumberOfPlumeHeigths which also describes the cardinality of the subsequent datasets denoted as heigths The different heigh
8. GOME 2 MetOp A at Zo Department Atmospheric Processors Applied Remote Sensing Cluster GOME ERS 2 GOME 2 MetOp A Product Navigation 0 273s zotero S gt O5 Now Snow 6 C gt Wed 4 C Thu 4 C x Figure 3 GOME 2 MetOp web pageat DLR 17 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 18 of 47 5 Total Column Trace Gasesand Cloud Products The level 2 total column products generated with the UPAS system contain retrieved trace gas vertical columns and cloud properties as well as other geophysical parameters corresponding errors on these quantities and a number of additional diagnostics quality flags and intermediate results 5 1 Units Dataset Units Total ozone and SO column amount Dobson Units DU Total H2O column amount kg m Othertrace gas column amounts molecules cni Cloud fraction and cloud top albedo optical thickness unitless Height km Pressure hPa Angles are given at Top of Atmosphere 70 km O to 360 degrees Geographical Coordinates longitude 0 to 360 degrees latitude 90 to 90 degrees Errors relative values 96 5 2 Geographical Coverageand Granularity GOME ERS 2 has a nominal global coverage at the equator after three days GOME 2 MetOp has a daily near
9. LineOfSightZenithAngleSatG float pixels degrees Line of sight zenith angle at satellite G RelativeAzimuthSatE float pixels degrees Relative azimuth at satellite E RelativeAzimuthSatCentre float pixels degrees Relative azimuth at satellite F RelativeAzimuthSatG float pixels degrees Relative azimuth at satellite G SubSatellitePointLongitude float pixels degrees Geodetic longitude of subsatellite point SubSatellitePointLatitude float pixels degrees Geodetic latitude of subsatellite point SatelliteAltitude float pixels km Geodetic altitude of satellite EarthRadius float pixels km Radius of the Earth IndexInScan integer pixels Index of the pixel within the scan 0 2 forward scan 3 backwardscan SubPixellnScan integer pixels Subpixel within the scan 0 3 for GOME ERS 2 0 to 3 7 or 31 for GOME 2 MetOp ViewMode string pixels Nominal Scanning mode of the instrument at the time of NorthPolar acquisition SouthPolar 30 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 31 of 47 19 February 2010 Narrow Static SurfaceCondition Flag integer pixels Flag for different pixel retrieval conditions e g land sea sun glint or snow ice 6 4 TOTAL COLUMNS Group The data sets in the TOTAL COLUMNS group are given in the following tables Attributes attache
10. MainSpecies string windows Name of the main reference species retrieved in this fitting string window VCDQualityIndicator float windows Percentageof flagged pixels see QualityFlags 0 2 in 6 7 2 for 0 100965 this window 28 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 29 of 47 19 February 2010 6 3 GEOLOCATION Group The GEOLOCATION group contains information for seven different points for the ground pixel denoted by letters A to G in Figure 5 MetOp GOME mi et erg C3 B C at ground a TOA Figure 5 Ground Pixel Geometry 29 DLR GOME PUM 01 Iss Rev 2 C 19 February 2010 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 and Cloud Properties DLR Page 30 of 47 The data sets in the GEOLOCATION group are given in the following table Dataset Name Data Type Unit Description InternalPixelld integer pixels Internal ground pixel number Time UTC pixels ms Time ofthe observation in UTC format LongitudeCentre float pixels degrees Longitude of the centre of the ground pixel F LatitudeCentre float pixels degrees Latitude ofthe centre ofthe ground pixel F LongitudeA float pixels
11. km to 320 km x 40 km with five options allowed The mode with the largest footprint three steps with a total coverage of 960 km x 40 km provides global coverage at the equator within 3 days DLR developed the GOME Data Processor GDP system the operational ground segment for GOME ERS 2 GDP incorporates a Level 0 to 1 processing chain the complete GOME ERS data archive a DOAS based total column retrieval process Level 1 to 2 and processing chain for the generation of value added products 2 3 GOME 2 MetOp On 30 January 1998 the ESA Earth Observation Programme Board gave its final go aheadfor the MetOp Programme The instruments on the MetOp satellites are designedto produce high resolution images of the Earth s surface vertical temperature and humidity profiles and temperatures of the land and ocean surface on a global basis In addition there are instruments for monitoring trace gases and wind flow over the oceans This instrument payload is of significant value to meteorologists and other scientists particularly to those studying the global climate Given the need for global scale routine monitoring of the abundance and distribution of ozone and associated trace gas species a proposal was put forward for the inclusion of GOME 2 on the MetOp satellites MetOp A was launched on 19 October 2006 as part of the Initial Joint Polar System IJPS in co operation with NOAA in the USA The GOME 2 MetOp field of view of each step may be v
12. 1 if clear sky CloudOpticalThickness float pixels Cloud optical thickness 1 if clear sky CloudOpticalThickness Error float pixels Error on cloud optical thickness 1 if clear sky CloudTopPressure float pixels hPa Cloud top pressure 1 if clear sky CloudTopPressure_Error float pixels Error on cloud top pressure 1 if clear sky CloudType integer pixels ISCCP cloud type classification 1 if clear sky 1 cirrus 2 cirrostratus 3 deep convection 4 altocumulus 5 altostratus 6 nimbostratus 7 cumulus 8 stratocumulus 9 stratus CloudMode integer pixels Mode in which cloud parameters have been calculated O normal mode 1 snow ice mode SurfaceAlbedo float pixels Surface albedo usedfor cloud retrieval 32 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR and Cloud Properties Page 33 of 47 DLR GOME PUM 01 Iss Rev 2 C 19 February 2010 6 6 DETAILED_RESULTS Group The following table lists ancillary surface aerosol data and detailed processing results as stored in the DETAILED_RESULTS group Data sets see Figure 4 on page 25 are represented either as arrays of size N where N is the number of ground pixels in the product or as matrices of dimensions NxM for N the number of ground pixels denoted as pixels in the following tables and M the number of fitting windows denoted as windows in the following tab
13. HH MM SS 0 04 004 0 04 005 0 04 006 301 021 Latitude Longitude Centre 0 05 001 0 06 001 1 02 004 Repeat next 2 fields 4 times for four corners of a pixel 0 27 001 Latitude High Accuracy 0 28 001 Longitude High Accuracy 0 10 001 Height of land surface 0 14 019 Surface Albedo 0 0 1 0 0 07 025 Solar zenith angle 0 10 080 Viewing Zenith Angle 0 05 023 Sunto satellite azimuth difference 0 20 010 Cloud Cover 96 0 08 003 Vertical significance 2 Cloud top 0 07 004 Pressure pa 0 14 026 Albedo at the top of clouds 0 0 1 0 0 20 014 Height of top of clouds km 0 13 093 Cloud optical thickness 0 31 001 Delayed descriptor replication factor 2 0 07 004 Pressure Top 0 07 004 Pressure Bottom 0 08 043 Atmospheric chemical or physical constituent type seetable below 0 08 044 CAS registry number seetable below 0 15021 Integrated mass density kg m 2 24 000 First order statistics follow 2 36 000 Backward reference bitmap 0 31 001 Delayed descriptor replication factor 2 0 31 031 Data present indicator 0 1 0 01 031 Identification of originating generating centre 254 Eumetsat 0 01 032 Generating Application 1 0 08 023 First order statistics 7 Mean absolute error 0 31 001 Delayed descriptor replication factor 2 0 15 021 Integrated mass density kg m 41 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H2O HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Propert
14. a ree pis mob edito pla dien 15 4 3 Data Managements i eod te cR Hectora ier e Eso PO ER SENE 16 4 4 Quality Control and Monitoring nennen 16 4 5 Geophysical ValidaliOh i i esce Ente ote en 17 AB CISA SIC BS io dena bes a est vam uto RT Pests n Eso YR IER iq Sd ve E TRO 17 5 Total Column Trace Gasesand Cloud Products cesses 18 S FUNIS cec dot bere enfe on s era esse 18 5 2 Geographical Coverageand Granullarity cccccccccccccccccccceeceeeeeeeaeeeeeeeeaaeees 18 5 3 Rsszii Erica Fino NEM 18 5 4 DellVeb DETes E d rio DE EE bible E TERM Ee st Pousti bas boc NP RS EM 18 5 5 Expected ACGU aCy a En 19 5 6 Product Formals annehmen 19 57 Elle NEG oes recentium Fa xr bra ated Tce lala nig bad ue o pe o qp e n 20 5 8 Prod ct Dissernihiallor zs oed e QD RO ER 21 5 8 EGOME ERSE2 seems 21 58 2 GOME2 MEIOD Soehnle 21 5 9 Product Ordening 252 desee eet ae ED ard ak 22 5 9 TOGOMEIERS2 ere etes a ENTER A SAVE at teen dut 22 5 9 2 GOME 2 MGIUOD dote A eI a e echten RO Y ROVRO ERE RU CEN DEKO E RR 22 6 HDF5 Product Format Description eee eee e eee eee eee eee eene eee ente ette 23 OT SUCI ee ee ee be e MEI rue 24 6 1 1 Description of Common ItEMS ssscccccccccsssssessntsecceeeessssesesnneseeeeaes 25 6 2 META DATA GOUD eek 26 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropos
15. degrees Longitude A LatitudeA float pixels degrees Latitude A LongitudeB float pixels degrees Longitude B LatitudeB float pixels degrees Latitude B LongitudeC float pixels degrees Longitude C LatitudeC float pixels degrees Latitude C LongitudeD float pixels degrees Longitude D LatitudeD float pixels degrees Latitude D SolarZenithAngleE float pixels degrees Solar zenith angle at TOA E SolarZenithAngleCentre float pixels degrees Solar zenith angle at TOA F SolarZenithAngleG float pixels degrees Solar zenith angle at TOA G LineOfSightZenithAngleE float pixels degrees Line of sight zenith angle at TOA E LineOfSightZenithAngleCentre float pixels degrees Line of sight zenith angle at TOA F LineOfSightZenithAngleG float pixels degrees Line of sight zenith angle at TOA G RelativeAzimuthE float pixels degrees Relative azimuth at TOA E RelativeAzimuthCentre float pixels degrees Relative azimuth at TOA F RelativeAzimuthG float pixels degrees Relative azimuth at TOA G SolarZenithAngleSatE float pixels degrees Solar zenith angle at satellite E SolarZenithAngleSatCentre float pixels degrees Solar zenith angle at satellite F SolarZenithAngleSatG float pixels degrees Solar zenith angle at satellite G LineOfSightZenithAngleSatE float pixels degrees Line of sight zenith angle at satellite E LineOfSightZenithAngleSatCentr float pixels degrees Line of sight zenith angle at satellite F e
16. monitoring of global change and data reprocessing basedon enhanced methodology Information and data of O3M SAF products generated at DLR are disseminated through different channels through direct FTP push to authorized users and through the EUMETCast broadcast system for near real time users through the EUMETSAT user services and by individual ordering and delivery through DLR s on line user services EOWEB Figure 2 4 4 Quality Control and Monitoring The quality of the OL products is controlled before they are archived and disseminated to the users A dedicated quality control tool integrated into DLR s data management system displays a set of parameters generated automatically by UPAS for each processedorbit The quality control tool performs limit checks and computes some statistics to show the confidence levels of the product and its evolution within time DLR experts examine the displayed parameters and set the corresponding quality stamp only for the off line product 16 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 17 of 47 19 February 2010 4 5 Geophysical Validation The geophysical validation of the official GOME products is performed by independent partner organizations AUTH BIRA and FMI The validation is accomplished using ground based measurements available through the World Ozone and Ultravi
17. 0 Set if the total column mol cm retrieved for this ground pixel is outside the specified range 2 4 Largeerror in ESC lt 2 lt 50 lt 100 Not lt 50 Not Not Set if the ESC Error applicable applicable applicable value of this ground pixel exceedsthe specified threshold These flags give additional information about the quality of the total column retrieval If for example the fitting of the slant column does not succeed or in case of ozone the fitting results produce negative values flag O and also flag 1 and 2 is set to indicate this condition and the total column field will contain the fill value If the total column has been retrieved but is out of the specified range flag 1 is set If the associated slant column error exceedsa specific threshold flag 2 is set 36 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 37 of 47 19 February 2010 See VCDQualityIndicator in 6 2 on page 26 for the percentage of pixels which have been flagged as an overall quality indicator for the whole orbit 6 7 3 NO2Tropo Flag Flag Value Description 0 1 Polluted condition NO2Tropo and NO2 Corr values are available e NO2containsthe total column density basedon an unpolluted AMF e NO2 Corr contains the pollution corrected total column density e NO2Trop
18. BUFR format e Appendixes Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 9 of 47 19 February 2010 1 2 References 1 2 1 Applicable Documents Al Design Document for the GOME 2 Universal Processor for Atmospheric Spectrometers SAF O3M DLR DD 001 Issue 2 0 October 2003 A2 EECF to PAF Interface Specifications ER IS EPO GE 0102 Issue 3 0 January 1990 A3 UMARF to SAFs Interface Control Document EUM UMA ICD 004 Issue 3 12 April 2006 A4 Product Requirements Document SAF O3M FMI RQ PRD 001 Rev 06 May 2008 1 2 2 ReferenceDocuments R1 Algorithm Theoretical Basis Document for GOME 2 Total Column Products of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 and Cloud Properties GDP 4 4 for O3M SAF OTO and NTO DLR GOME 2 ATBD 01 Iss Rev 2 C 2010 R2 Algorithm Theoretical Basis Documentfor GOME Total Column Densities of Ozone and Nitrogen Dioxide UPAS GDOAS GDP 4 0 ERSE DTEX EOPG TN 04 0007 Iss Rev 1 A December 2004 R3 Delta Validation Report for ERS 2 GOME Data Processor upgradeto version 4 0 ERSE CLVL EOPG TN 04 0001 Iss Rev 1 0 December 2004 R4 Product Specification Document of the GOME Data Processor ER PS DLR GO 0016 Iss Rev 4 B December 2004 R5 GOME 2 Level 1 Product Format Specification EPS MIS SPE 97232 2008 R6 GOME 2 Products
19. CC ReceivingCentre ECF FBK FUC GCA PGS RUS SOC SVL UBI WAL WEC WIV SMOD InstrumentMode e g NARROW NORMAL or STATIC SNIT Applicable CCSDS date SSBT SensingStartTime CCSDS date 46 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 47 of 47 19 February 2010 SSST SensingEndTime CCSDS date Parameteris not contained in the HDF5 product but will be provided by DIMS 47
20. Cloud fraction CF lt 10 lt 10 Cloud top height cloud top CTH CTP lt 10 10 pressure Cloud top albedo cloud optical CTA COT lt 10 10 thickness The algorithms used for NRT and OL processing are the same this meansthat NRT and OL products have the sameaccuracy and precision 5 6 ProductFormats The format of the product file is either HDF5 or BUFR A detail description of the HDF5 product format is given in section 6 on page 23 and for the BUFR product in section 7 on page 39 19 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 20 of 47 5 7 File Name The file name of a product already contains important information about the dataset including trace gasesand sensingtime It is built according to the following structure SENSOR GAS LV YYYYMMDDhhmmss ddd MISSION 7EHHHE PRO RV TYPE where e SENSOR denotesthe instrument i e GOME e GAS is a separated list of trace gasesincluded in the product The acronyms from the above table are used e g O3 NO2 BrO is a products containing thesethree trace gases e LV is the product level i e L2 e YYYYMMDD arethe year month and day of the first processedground pixel e hhmmss are the hours minutes and seconds of the UTC time stamp of the first processedground pixel e ddd isthethree digit d
21. DLR Product User Manual for GOME Total Columnsof Ozone NO SO BrO H20 HCHO OCIO tropospheric NO and Cloud Properties O3M SAF OTO and NTO Dobson Units 200 300 400 Doc No DLR GOME PUM O1 Iss Rev 2 C Date 19 February 2010 Deutsches Zentrum f r Luft und Raumfahrt e V DLR Oberpfaffenhofen Germany DLR GOME PUM 01 Iss Rev 2 C Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties Page 2 of 47 DLR Signatures Action Name Affiliation Function Date Signature prepared by D Loyola R DLR MF GOME Project Manager W Zimmer DLR MF GOME Project Engineer 19 February S Kiemle DLR DFD DIMS Project Manager 2010 P Valks DLR MF GOME Project Scientist S Emmadi DLR DFD GOME Project Engineer BUFR v3 by former L Butenko DLR MF GOME Project Engineer nz HDF5 by former 1 November Y Livschitz DLR MF GOME Project Engineer 2004 released by 19 February D Loyola R DLR MF GOME Project Manager 2010 Distribution List Function Organization UPAS Team DLR MF DLR DFD GOME ERS 2 Team ESA BIRA RTS AUTH various O3M SAF Team EUMETSAT FMI AUTH BIRA KNMI various Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cl
22. EEE F64LE string H5T C S1 UTC H5T COMPOUND H5T STD I32LE Day H5T STD I32LE MillisecondOfDay where Day denotes number of days since 1st of January 1950 VIEW MODES H5T COMPOUND H5T STD I32LE NominalPixels H5T STD I32LE StaticPixels H5T STD I32LE NarrowPixels H5T STD I32LE PolarSouthPixels H5T STD I32LE PolarNorthPixels CCSDS_ASCII The format for ASCII Time Code is YYYY MM DDThh mm ss ddd where YYYY Year in four character subfield with values 0001 9999 MM Month in two character subfield with values 01 12 DD Day of month in two character subfield with values 01 28 29 30 or 31 T Calendar Time separator hh Hour in two character subfield with values 00 23 mm Minute in two character subfield with values 00 59 ss Secondin two character subfield with values 00 59 ddd Decimal fraction of second where each d has values 0 9 POS VEC H5T COMPOUND H5T IEEE F64LE X H5T IEEE F6A4LE Y H5T IEEE F64LE Z A4 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 45 of 47 19 February 2010 A 2 Traceability Matrix of HDF5 Metadata to EECF Parameters The EECF metadata parameters A2 which are applicable to the D PAF products are stored in the HDF5 file as attributes in the META DATA group The tracing of EECF parameters to the attributes in the product file is indic
23. Guide EUM OPS EPS MAN 05 0005 Issue 1 0 February 2005 R7 HDFS5 File Format Specification http www hdfgroup org HDF5 R8 BUFR Format Specification http www wmo int pages prog www WDM Guides Guide binary 1A html 9 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 10 of 47 1 3 Abbreviationsand Acronyms A list of abbreviations and acronyms used throughout this document is given below AAIA AMF BIRA IASB BUFR CCSDS DLR DOAS D PAF DU EPS ERS 2 ESA ESC EUMETSAT GDOAS GDP GOME HDF IMF MetOp NRT NT NTO O3M SAF OL OTO PDU PMD RP RMS SAF SZA TBD TOA UMARF UV UPAS UTC VCD VIS Absorbing Aerosol Indicator Algorithm Air Mass Factor Belgian Institute for Space Aeronomy Binary Universal Form for the Representation of meteorological data Consultative Committee for Space Data Systems Deutsches Zentrum f r Luft und Raumfahrt e V German Aerospace Centre Differential Optical Absorption Spectroscopy German processing and archiving facility Dobson Unit EUMETSAT Polar System European Remote Sensing Satellite 2 European Space Agency Effective Slant Column European Organisation for the Exploitation of Meteorological Satellites GODFIT DOAS GOME Data Processor Global Ozone Monitoring Experiment Hierarchical Data Format Remote Sensing Technolo
24. Optional section included Bits 2 8 setto zero reserved 0 11 Data Category type BUFR Table A 3 12 Data Category subtype defined by local ADP centres 255 13 Local data sub category 206 14 Version number of master tables used currently 2 for WMO FM 94 BUFR tables 11 15 Version number of local tables used to augment the master table in use 0 16 17 Year 2XXX 18 Month 1 12 19 Day 1 31 20 Hour 0 23 21 Minute 0 59 22 Second 0 59 7 5 Section3 Indicator Section ma Allowed Used Octet Description Values 1 3 Length of section in octets 4 Set to zero reserved 5 6 Number of data subsets 200 7 Bit 1 1 observed data 192 0 other data Bit 2 1 compresseddata 0 non compressed data Bit 3 8 set to zero reserved 8 A collection of descriptors which define the form and content of individual data elements comprising one data subset in the data section 40 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 and Cloud Properties DLR GOME PUM 01 Iss Rev 2 C DLR Page 41 of 47 19 February 2010 7 6 Section3 UPAS Level 2 Specific List of Descriptors Descriptor Description Value 0 01 007 Satellite Identifier 5 Metop 2 002019 Satellite Instruments 220 GOME 2 301011 Date in format YYYY MM DD 0 04 001 0 04 002 0 04 003 301 013 Time in format
25. S Date NumberOfGroundPixels integer Number of ground pixels in the product int DegradedRecordCount integer Number of records which could not be processed by the int software DegradedRecordPercentage integer Percentage of records which could not be processed by 0 100 the software 27 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 28 of 47 MissingDataCount integer Number of missing data records int MissingDataPercentage integer Percentage of missing data records 0 100 The next table contains metadata specific to the total column products Ts Allowed Attribute Name Data Type Description Values NumberOfFittingW indows integer Number of fitting windows usedin processing 1 M FittingFlag integer Flag indexing DOAS fitting algorithm settings bitmap AMFFlag integer Flag indexing AMF algorithm settings bitmap VCDFlag integer Flag indexing VCD algorithm settings Bitmap This table describes data sets containing information about the fitting windows EH Allowed DatasetName Data Type Description Values FWName string windows Namesof fitting windows string FWLowerBound float windows Lower wavelength bound of a fitting window in nm 240 780 FWUpperBound float windows Upper wavelength bound of a fitting window in nm 240 780
26. a all that is necessary is the publication of additional data description tables Similarly for the deletion of possibly outdated observations instead of having to send missing indicators for a long period while awaiting a change to a fixed format code the missing data are simply not sent in the messageand the data description section is adjusted accordingly The data description tables are not changed however so that archives of old data may be retrieved The data encoded in BUFR format is purely binary or bit oriented thus making it both machine dependent and at the sametime machine independent The dependency comesin the construction or interpretation of BUFR messages there is not much for a human to look at as all the numbers in a message whether data descriptors or the data themselves are binary integers And that of course leads to the machine independence with BUFR consisting entirely of binary integers any brand of machine can handle BUFR as well as any other Theoretically there is no upper limit to the size of a BUFR message but by convention BUFR messagesare restricted to 15000 octets or 120000 bits This limit is to allow an entire BUFR messageto be contained within memory of most computers for decoding It is also a limit set by the capabilities of the Global Telecommunications System GTS of the WMO In UPAS the length of a single BUFR messageis limited to 200 ground pixels that gives approximately 10Kbytes for s
27. ame Notes AARF ArchiveFacility possible values D PAF DLR OP ERS O3DLR METOP ABID ProductContents Spectral Band Ids AllD InstrumentlD GOME APAS Applicable Product Size APNA Applicable Product Name APNM ProductType e g O3MOTO O3MNTO APPN BaseProducts Parent Product Name ASTI SatellitelD possible values ERS M01 M02 M03 for METOP AVBA BaseProductAlgorithmVersion AVPA ProductAlgorithmVersion Concatenation of the HDF5 attributes ProductAlgorithmVersion InitializationFile Version InternalProcessorRevision and Revision GDMD Applicable Disposition Mode T O or P GGTP Applicable GranuleType DP GNFV ProductFormatVersion GORT Applicable OrbitType LEO GPLV ProcessingLevel 02 or 03 GPMD ProcessingMode N B R V LLAE SubSatellitePointEndLat 90 0000 to 89 9999 LLAS SubSatellitePointStartLat 90 0000 to 89 9999 LLOE SubSatellitePointEndLon 180 0000 to 179 9999 LLOS SubSatellitePointStartLon 180 0000 to 179 9999 LONS StartOrbitNumber LSVL OrbitAscendingNodeLongitude 180 0000 to 179 9999 LSVT OrbitAscendingNodeCrossingDateTime CCSDS date PPRC ProcessingCentre possible values D PAF DLR OP ERS O3DLR METOP PPST Processing End Date and Time CCSDS date QDLC MissingDataCount QDLP MissingDataPercentage QDRC DegradedRecordCount QDRP DegradedRecordPercentage QQAI Applicable Associated Quality Information QQOV Applicable Overall quality flag OK NOK RR
28. aried in size from 5 km x 40 km to 80 km x 40 km The mode with the largest footprint twenty four steps with a total coverage of 1920 km x 40 km provides daily near global coverage at the equator R6 Basedon the successfully work with the GOME Data Processors the German Aerospace Centre DLR plays a major role in the design implementation and operation of the GOME 2 MetOp ground segment for total column products DLR is a partner in the Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring O3M SAF which is part of the Eumetsat Polar System EPS ground segment and is responsible in this project for the generation of total column amounts of the various trace gases and cloud properties which may be retrieved from GOME 2 MetOp level 1b products 3 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 13 of 47 19 February 2010 2 4 Measurement Scenarios Timelinesand Instrument Modes GOME ERS 2 and GOME 2 MetOp follow in general the sameoperational scenarios see http gome eumetsat int http www eumetsat in EPSCalValExtranet Main GOMECalVal index htm for more details e Earth Observation Mode This mode includes nadir narrow static north polar south polar scanning measurements with various integration times depending on solar zenith angle This is the default mode for the day side Only the
29. ated in the following table Attributes can only take values which are allowed by EECF EECF Short Name Attribute Name Notes SATELLITE ID SatellitelD possible values ERS M01 M02 for METOP SENSOR_ID InstrumentID GOME ORBIT_NO StartOrbitNumber ACQUISITION_FACILITY_ID ReceivingCentre ECF FBK FUC GCA PGS RUS SOC SVL UBI WAL WEC WIV PROCESSING_FACILITY_ID ProcessingCentre ArchiveFacility D PAF DLR OP ERS O3DLR METOP PROCESSING_DATE_TIME ProcessingTime TEMPORAL_COVERAGE_START SensingStartTime TEMPORAL COVERAGE STOP SensingEndTime SOFTWARE VERSION ProductAlgorithmVersion AUX DATA InitializationFileVersion PRODUCT TYPE ProcessingL evel 02 or 03 REVISION Revision SOURCE ITEM BaseProducts 45 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 46 of 47 A 3 Traceability Matrix of HDF5 Metadata to UMARF Parameters The UMARF metadata parameters A3 applicable to the O3M SAF products are stored in the HDF5 file as attributes in the META_DATA group The mapping of UMARF parametersto product file attributes is shown below again attributes can only take values allowed by UMARF NR Attribute N
30. d to all data sets in this group are the same as those for the GEOLOCATION group This group contains the key trace gas total column information Data sets are arrays of size N where N is the number of ground pixels in the product granule All entries starting with the name of the trace gas are only included if the trace gas total column has been retrieved in which caseit is included in the META DATA MainSpecies attribute DatasetName Data Type Unit Description O3 float pixels Dobson Units Total vertical column density of O3 O3 Error float pixels Error on total vertical column density of O3 O3Tropo float pixels Dobson Units Tropospheric vertical column density of O3 O3Tropo Error float pixels Error on tropospheric vertical column density of O3 NO2 float pixels molecules cn Total vertical column density of NO2 corrected for tropospheric contribution NO2_Error float pixels Error on corrected total vertical column density of NO2 NO2Tropo float pixels molecules cn Tropospheric vertical column density of NO2 NO2Tropo_Error float pixels Error on tropospheric vertical column density of NO2 SO2 float pixels Dobson Units Vertical column density of SO2 SO2_Error float pixels Error on vertical column density of SO2 BrO float pixels molecules cn Vertical column density of BrO BrO_Error float pixels Erro
31. data acquired in this mode are used for geophysical retrievals e Calibration Modes This mode includes Sun Moon dark spectral light LED white light measurements Most of this calibrations are performed on the night side The effective optical throughput and the potential data rate for GOME 2 MetOp are much higher than those for GOME ERS 2 The default integration times for GOME 2 MetOp is 4 to 8 times smaller than those for GOME ERS 2 1 The effective optical throughput is enhanced by approximately a factor of 2 and co adding as used for GOME ERS 2 is not required becauseof the higher data rate 10 times faster 13 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 14 of 47 3 Algorithm Description 3 1 Summary The GOME Data Processor GDP operational algorithm is the baseline algorithm for the trace gas column retrievals from GOME ERS 2 and GOME 2 MetOp The latest GDP 4 x usesan optimised DOAS Differential Optical Absorption Spectroscopy algorithm to determine the trace gas slant column The DOAS slant column fitting is followed by Air Mass Factor AMF conversions to generate vertical columns Cloud information used in the trace gas retrieval is obtained with the OCRA and ROCINN algorithms A detailed description of the GDP algorithm is givenin R1 and R2 3 2 Trace Gas and Cloud Product
32. ghost column and AMF values with corresponding errors e Fitting diagnostics chi square RMS etc e Various subgroupsfor trace gas specific data e g O3 NO2Tropo SO2 23 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 24 of 47 6 1 Structure The data in the HDF5 file is organized in five groups META_DATA GEOLOCATION TOTAL_COLUMNS DETAILED_RESULTS CLOUD_PROPERTIES Figure 4 The values in all groups are either copied from the level 1 R4 R5 or other input data or calculated by the UPAS level 1 to 2 processor The META_DATA group contains parameters required by EECF A2 or UMARF A3 and general information about the product The data related to each ground pixel is divided into three groups GEOLOCATION TOTAL COLUMNS and DETAILED RESULTS The GEOLOCATION group contains all information related to geolocation of the pixel Pixel processing information is stored in the TOTAL COLUMNS and DETAILED RESULTS groups Cloud properties derived are stored in the CLOUD PROPERTIES group The last three groups mentioned above contain all pixel information stored in arrays with length equal to the number of ground pixels in one granule orbit or PDU Data values may occur more than once for a given ground pixel and these will be separated by fitting windows The information for each entry is stored a
33. global coverage at the equator Depending on the scanning mode used the measured ground pattern may be different The NRT operational OL and reprocessed products have by default a global coverage The coverage of trace gases available only under special conditions may be reduced e g SO measured during volcanic eruption The NRT products have the same granularity as the downlink or PDU The OL and reprocessedproducts are consolidated orbits from ascending node to ascending node 5 3 Spatial Resolution GOME ERS 2 has three forward scan pixels with a nominal resolution of 40 km x 320 km and one back scan pixel with a nominal resolution of 40 km x 960 km GOME 2 MetOp has 24 forward scan pixels with a nominal resolution of 40 km x 80 km and8 back scanpixels with a nominal resolution of 40 km x 240 km Both forward and back scanpixels are generally processedand written to the products 5 4 Delivery Time DLR generates near real time NRT off line OL and reprocessed products RP The 18 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 19 of 47 19 February 2010 NRT products are available for distribution in less than 15 minutes after the reception of the GOME level 0 or level 1 product Assuming that the input data is received at DLR 1 45 hours after sensing then the GOME total column products will be dissemi
34. gy Institute Operational Meteorological Satellite Near Real Time Nominal Time Identifier used for near real time total column and cloud products SAF on Ozone and Atmospheric Chemistry Monitoring Off Line Identifier usedfor off line total column and cloud products Product Dissemination Unit Polarisation Measurement Device Postfix identifier user for reprocessedtotal column and cloud products Root Mean Square Satellite Application Facility Solar Zenith Angle To be Defined Top of Atmosphere Unified Meteorological Archiving and Retrieval Facility Ultra Violet Universal Processor for Uv vis Atmospheric Spectrometers Universal Time Coordinate Vertical Column Density Visible 10 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 11 of 47 19 February 2010 2 GOME Instruments 2 1 Introduction The Global Ozone Monitoring Experiment GOME is a scanning spectrometer that captures light reflected from the Earth s surface and atmosphere The spectrometer splits the light into its spectral components covering the UV VIS region from 240 nm to 790 nm at a resolution of 0 2 nmto 0 4 nm The measured spectra are mainly used to derive ozone total column and vertical profile nitrogen dioxide bromine oxide water vapour oxygen sulphur oxide and other trace gases as well as cloud properties and aerosols The nex
35. ies DLR Page 42 of 47 7 7 Section4 Indicator section Octet Description Allowed Values 1 3 Length of section in octets 4 Setto zero reserved 5 Binary data as defined by descriptors which begin at octet 8 Section 3 7 8 Section5 End Section Octet Description Allowed Values 1 4 7777 coded according to the CCITT International Alphabet No 5 7777 7 9 Trace Gas Table The following field valuesare usedfor the different trace gases 42 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 43 of 47 19 February 2010 8 Using the Products This section contains practical information on using the GOME products As a general advise it is strongly recommended to use only the forward scan pixels and discard the back scan pixels Back scan pixels are not only redundant but they are less accurate than the forward scan pixels due to their larger footprint size The IndexInScan attribute from the GEOLOCATION group in the HDF5 products has values of 0 1 2 for East Nadir West forward scan pixels back scan pixels can be easily filtered out checking that IndexInScan lt 3 Back scan pixels are not included in the BUFR products The H20 entry in the TOTAL_COLUMNS group of the HDF5 products is set to fill value for measurements under cloudy conditions The retrieval
36. ifier ProductType string Description of the product type ERSNTO O3MNTO ERSOTO O3MOTO 26 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 27 of 47 19 February 2010 ny Allowed Attri Nam Data T Description ttribute Name ata Type escriptio Values ProcessingL evel string Processing level applied for generation of the product 02 ProcessingTime CCSDS ASCII UTC date and time at processing finish CCSDS Date BaseProductAlgorithmVersion string Version of the algorithm used to generate the L1B string parent product upon which the L2 product is based BaseProducts string Name of the base products string ProductAlgorithmVersion string Version of the algorithm that produced the product string InitializationFileVersion string Version of the configuration file usedfor processing string InternalProcessorRevision string Version of the processor used to generate this product string ProductFormatType string Data format of the product HDF5 ProductFormatVersion string Version number of the product format string ProductContents string Trace gasesincluded in the product comma separated string list SubsettingRegion string Description of the sub setting region full means no string subsisting was applied
37. le and disseminated to the users two weeks up to four weeks in caseof GOME ERS 2 after sensing Additionally DLR provides reprocessed products for climate applications The complete GOME ERS 2 data record starting in 1995 has been reprocessed and validated every two to three years using improved algorithms In the same way the complete GOME 2 MetOp data record starting in 2007 was reprocessedand validated in 2010 GOME ERS 2 and GOME 2 MetOp provide a unique data record of atmospheric measurements covering a time frame of around 25 years DLR together with the partner organizations ESA and EUMETSAT will assure the continuity between GOME ERS 2 and GOME 2 MetOp total column products In this framework it is important to provide to the users a unified data format for accessing the GOME products The Hierarchical Data Format HDF and the Binary Universal Form for the Representation of meteorological data BUFR have been selected for the GOME total column products HDF and BUFR are self describing machineindependent file formats commonly used for storage andtransfer of scientific and meteorological data The present documentis divided into the following sections e Overview of the GOME ERS 2 and GOME 2 MetOp instruments including instrument modes e Summary of the algorithms used for the retrieval of trace gasestotal columns and cloud properties e Summary of the processing steps e Product description including the used HDF5 and
38. les DatasetName Data Type Unit Description AAI float pixels Absorbing aerosol indicator SurfaceHeight float pixels km Surface altitude SurfacePressure float pixels hPa Pressure at the surface level SurfaceAlbedo float pixels windows Surface albedo for the associated retrieval window VCD float pixels windows mol cm Vertical column density of main parameter value VCD_Error float pixels windows Error on vertical column density IntensityWeightedCloudFraction float pixels windows Weighting factor between clear sky and cloudy AMFs ESC float pixels windows mol cm Retrieved effective slant column ESC Error float pixels windows Error on effective slant column FittingRMS float pixels windows RMS of the fit FittingChiSquare float pixels windows Square of Chi FittingGoodness float pixels windows Goodness of fit for the fitting window FittingNumberOflterations integer pixels windows Number of iterations of nondinear fitting GhostColumn float pixels windows mol cm Ghost column usedin VCD AMFClear float pixels windows AMF to ground for species AMFClear_Error float pixels windows Error on AMF to ground AMFCloud float pixels windows AMF to cloud top for species 1 if clear sky AMFCloud_Error float pixels windows Error on AMF to cloud top 1 if clear sky AMF Total float pixels windows Total AMF
39. natedto the usersin lessthan 2 hours after sensing The GOME 2 MetOp OL products are available two weeks after sensing The GOME ERS 2 OL products are available up to four weeks after sensing due to constraints on the current level 0 data dissemination ReprocessedGOME ERS and GOME 2 MetOp level 2 products using the latest level 1 data and improved retrieval algorithms are available every two to three years 5 5 Expected Accuracy The following table lists the GOME total column trace gasesand cloud products provided by DLR together with estimated uncertainties Product Acronym Expected Accuracy ExpectedPrecision Total ozone column 03 3 6 4 3 SZA lt 80 2 4 3 3 SZA lt 80 6 4 7 2 80 lt SZA lt 90 4 9 5 996 80 lt SZA lt 90 Tropospheric ozone column O3Tropo 20 4096 20 4096 Total NO column NO2 5 10 unpolluted conditions 3 1096 unpolluted conditions Tropospheric NO column NO2Tropo 50 10096 polluted conditions 50 100 polluted conditions gt 100 unpolluted gt 100 unpolluted Total BrO column BrO 20 50 10 50 Total H O column H20 5 20 10 25 Total SO column so2 50 100 SZA lt 70 20 50 SZA lt 70 gt 100 SZA gt 70 gt 50 SZA gt 70 Total HCHO column HCHO 50 100 polluted conditions 20 50 polluted conditions gt 100 unpolluted gt 100 unpolluted Total OCIO column OCIO 50 100 SZA gt 75 20 50 SZA gt 75
40. nual for the GOME ERS 2 and GOME 2 MetOp total column trace gases and cloud products available at DLR In this document the terms GOME ERS 2 and GOME 2 MetOp are used to reference the specific instruments The general term GOME appliesto both sensors Thetrace gasestotal column products are e Ozone O total column e Nitrogen dioxide NO total column e Sulphur dioxide SO total column e Bromide monoxide BrO total column e Water vapour H O total column e Formaldehyde HCHO total column e Chlorine dioxide OCIO total column Thetrace gasestropospheric column products are e Nitrogen dioxide tropospheric column e Ozone tropospheric column Additionaly DLR provides the following cloud properties derived from GOME measurements e Cloud fraction CF e Cloud top albedo CTA and cloud optical thickness COT e Cloud top height CTH and cloud top pressure CTP DLR provides near real time NRT off line OL and reprocessed products The NRT products have the same granularity as the input GOME data i e downlink or PDU and xig DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 8 of 47 are made available and disseminated to the users within 2 hours 30 minutes of sensing The OL products are consolidated orbits from ascending node crossing to ascending node crossing and are availab
41. o contains the tropospheric column density Note ntensityWeightedCloudFraction 50 1 2 Unpolluted condition NO2Tropo and NO2 Corr not available fill values e NO2containsthe total column density basedon an unpolluted AMF Note ntensityWeightedCloudFraction lt 50 2 4 Cloudycondition NO2Tropo and NO2 Corr not available fill values e NO2 contains the total column density basedon an unpolluted AMF Note ntensityWeightedCloudFraction gt 50 3 8 Measurementin polar regions Lat gt 70 deg NO2Tropo and NO2 Corr not available fill values e NO2containsthe total column density basedon an unpolluted AMF 4 16 NO2 column data not available e NO2 NO2Tropo and NO2 Corr contain fill values 6 7 4 SO2 Flag Flag Value Description 0 1 Measurementin polar regions SZA gt 75 deg e reduced quality of SO2 total column 1 2 SO2column data not available e SO2 andSC2 Corr contain fill values 6 7 5 H20O Flag Flag Value Description 0 1 Measurementin cloudy conditions e reduced quality of H2O total column 1 2 Measurementin cloudyand or elevation conditions small O2 e reduced quality of H2O total column 6 7 6 HCHO Flag Flag Value Description 0 1 Measurement with high solar zenith angle SZA gt 70 deg e reduced quality of HCHO total column 37 DLR GOME PUM 01 Product User Manual for GOME To
42. olet radiation Data Centre ground based measurements from the NDACC network other satellite data as well as data assimilation techniques The validation results are publicly available on the Internet seesection 5 9 4 6 User Services Information about data and services are accessible through the websites given in section 5 9 andat the end of this section The interactive catalogue and ordering interface EOWEB from DLR allows individual product searchesand ordering Catalogue information from the O3M SAF products generated at DLR are regularly made available to the central EUMETSAT facility UMARF The users can query the catalogue of the UMARF and submit their request the UMARF facility will then send to each SAFs orders requested by the end users about SAF products catalogued in UMARF DLR s data management system will then deliver the requested products to the user DLR operates additionally on line user services on remote sensing data in the framework of the World Data Center for Remote Sensing of the Atmosphere WDC RSAT http wdc dlr de left side of Figure 2 GOME 2 MetOp images and value added products produced at DLR and partner organizations are available at http atmos caf dlr de gome2 see Figure 3 GOME 2 MetOp A at DLR Mozilla Firefox lt 2 gt File Edit View History Bookmarks Tools Help TT gt AG B http atmos caf dir de gome2 v e I LEO Ergebnisse f r Microsoft Outlook We gt
43. oud Properties Iss Rev 2 C DLR Page 3 of 47 19 February 2010 Document ChangeLog Issue Rev Date Section Description of Change 1 A 31 July 2004 all HDF5 and BUFR output product format to documents merged in this product user 20 July 2006 manual 1 B 5 October 4 5 Content of chapters added 2006 1 C 10 November all First official version of this document 2006 1 D 6 March 2007 5 7 Fix file name convention 6 2 6 5 Added VCDQualityIndicator QualityFlags CloudMode CloudType AMFTotal AMFTotal Error OrbitActualDuration new receiving stations 1 E 30 April 2008 all Revised following ORR A 6 Added in HDF5 section IterativeVCDNumberOflterations a priori O3 Profile T Profile 7 BUFR product update to BUFR version 4 2 A 9 December all Revised following ORR B 2008 28 January 6 Finalized HDF5 product format 2009 Moved trace gas specific datasets into own groups inside DETAILED RESULTS Moved cloud properties into own group 2 B 16 November 6 Update H2O and HCHO format new 2009 sections 6 6 4 6 6 5 6 7 4 6 7 5 Minor corrections SurfaceAlbedoRW gt SurfaceAlbedo Total Columns and BrO cleanup 18 December 6 PixelFlag under Geolocation section is 2009 renamed to SurfaceConditionFlag SurfaceConditionFlag definition added H2OFlag definition changed DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 Feb
44. pheric NO2 DLR 19 February 2010 and Cloud Properties Page 6 of 47 63 GEOLOCA TION GUOUD s unseren 29 SA TOTAL COPUIMING GEODDG a een ss ee 31 6 5 CLOUD PROPERTIES GroUD aussehen 32 6 6 DETAILED RESULTS GIOHBD str Pe OR PROCHE P Rea Bee Cha Rer vt 33 6 6 1 DETAILED RESULTS O3 Subgfoup cccececcceceeeeeeeeeeeeeeaeeeeeeeeeeees 34 6 6 2 DETAILED RESULTS NO 2 Subgroup se 34 6 6 3 DETAILED RESULTS SO2 Subgroup eee 35 6 6 4 DETAILED RESULTS H2O Subgfoup cccccccccccccccccececeeeeeeeeeeeeeaaaes 35 6 6 5 DETAILED RESULTS HCHO Subgroup eene 35 6 7 Detailed Flag DescriptiOn iiie eren een Rae lanua 36 6 7 1 SurfaceConditionFlag unto ec ict ob Peto Qr goa d ean Pads 36 67 2 Quality Flags aaa ns Dau Ru ea 36 6 7 3 NOZTEIODO F BQ oes eterne a II BR 37 674 S02 Pages I a Ce tay Oe Eti 37 6 9 5720 EIU dut eet cod e eco ida itta om pet o as 37 67 0 HCHO Flag oiii ausge 37 7 BUFR Product Format Description 22022222s222ssssnsnnnnnnnnnnnnnnnnssssnnnsssnee 39 A pron i Bless eek 39 7 2 WMO GTS Bulletin Identifier eese 39 7 3 Section 0 Indicator Sections anderen 40 7 4 Section 1 Identification Section nennen 40 7 5 Section 3 Indicator Section u corso recien eH moni reet Eee ee P Hd Eun ek 40 7 6 Section 3 UPAS Level 2 Specific List of Descriptors
45. r on vertical column density of BrO BrOTropo float pixels molecules cn Tropospheric vertical column density of BrO BrOTropo_Error float pixels Error on tropospheric vertical column density of BrO H20 float pixels kg m Vertical column density of H2O H20 Error float pixels Error on vertical column density of H2O HCHO float pixels molecules cn Vertical column density of HCHO HCHO Error float pixels Error on vertical column density of HCHO OCIO float pixels molecules cn Slant column density of OCIO OCIO Error float pixels Error on slant column density of OCIO for future use not yet implemented 31 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 32 of 47 6 5 CLOUD PROPERTIES Group In this group the main cloud properties of each pixel are stored DatasetName Data Type Unit Description CloudFraction float pixels Cloud fraction CloudFraction Error float pixels Error on cloud fraction CloudTopAlbedo float pixels Cloud top albedo 1 if clear sky CloudTopAlbedo_Error float pixels Error on cloud top albedo 1 if clear sky CloudTopHeight float pixels km Cloud top height 1 if clear sky CloudTopHeight_Error float pixels Error on cloud top height
46. ruary 2010 and Cloud Properties Page 4 of 47 DLR 2 C 19 February 1 1 Add reference to reprocessed GOME 2 2010 5 92 Add new O3M SAF logo and web page 7 2 Add WMO GTS bulletin identifier 8 New section Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 5 of 47 19 February 2010 Table of Contents 1 1HLOdUcHoONn xao tide d cn osx orisni aee a iada aaiae Esak ia oia isa 7 1 7 P rposeand ScOpe tiser en on e pete ar desta tet Cb taber re 7 12 FRETS TINGS s es cessent es anser toc a Ret Ob VERUS NN c dade ed 9 1 2 1 Applicable Documents eene nennen nnn nnn 9 1 2 2 Reference Document 9 1 3 Abbreviations and ACronyMs ssssssssssesssssssssssssssssssssssssssssssesssesssessessseecs 10 z4 ie 28 pino zy cM stoso sosss 11 2 T AVEO CLIO uu seen ee Ee ipte Raves d p E Saeko 11 22 5D0MEIERS 2 oet a aO e e tuu PR CON RERO UE a RO Ra NO CRT 12 2 3 GO0ME 2Z MeTODL ea d dots o Oe CD RE RR UN DS 12 2 4 Measurement Scenarios Timelines and Instrument Modes 13 3 Algorithm Descriptor susanne 14 3 1 SURE ne Sn RN aede ec SN LER Renai 14 3 2 Trace Gas and Cloud Products ccccccccccecceeesessseeeeceeeeeeeesaaeeseeeeeeeeesenseees 14 A PLOCESSING NR 15 IL TGOME EBRS 2 eet SERO RHEIN UU ruin Ete PHI IG Eum 15 4 2 GOMER MELO as Sic apii Ge se pi reist de
47. s The GOME ERS 2 and GOME 2 MetOp trace gas column densities and cloud properties level 2 product are retrieved from GOME ir radianceand PMD data level 1 product The following table lists the trace gas column and cloud products provided by DLR and the corresponding wavelength regions used for the retrieval Product Wavelength region nm O column 325 0 335 0 NO column 425 0 450 0 BrO column 336 0 351 5 SO column 315 0 326 0 H O column 611 0 700 0 HCHO column 328 5 346 0 OCIO column 365 0 389 0 Cloud fraction 300 800 PMD p Cloud top height pressure and 758 0 771 0 albedo cloud optical thickness 14 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 15 of 47 19 February 2010 4 Processing The Universal Processor for UV VIS Atmospheric Spectrometers UPAS is the core GOME retrieval system at DLR A1 UPAS is a new generation Level 2 system for the processing of operational near real time and off line trace gas and cloud properties products UPAS takes as input the calibrated and geolocated Level 1 radiances from different sensors e g GOME ERS and GOME 2 MetOp and produces total columns of trace gases e g O NO BrO H O SO HCHO and OCIO and cloud properties cloud fraction cloud top albedo and height The UPAS system is based on a scalable clien
48. s a matrix Elements in these matrices are not always atomic they can contain variable length data structures When entries for a pixel or pixel window combination cannot be calculated using the normal processing procedure fill in values are written to the arrays Also not all datasets defined here haveto exists in every product Pleasenote that this description is only valid for the actual version of the product format currently 2 C The version of a GOME HDFS5 level 2 product can reliably be read from the field META DATA ProductFormatVersion therefore a reader can implement several versionsin parallel Each array has five attributes Title Unit FillValue ValueRangeMin and ValueRangeMax Figure 4 Theseare usedto describe the contents of the array Valuesin the META DATA group are stored asattributes of the group 24 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 25 of 47 19 February 2010 META_DATA GEOLOCATION Attributes present for every dataset Time 0 12 N Title Longitude 0 1 2 N Unit Latitude 01 2 N FillValue ValueRangeMin TOTAL COLUMNS ValueRangeMax 03 01 2 N Noz 0112 N N nuber of ground pixels BrO 0112 N M nuber of fitting windows CLOUD_PROPERTIES CloudFraction 0 1 2 N
49. s is EumetCast using the BURF and HDF5 format The NRT products in BUFR format are additionally disseminated via WMO GTS The corresponding bulletin identifier for the O3M SAF Products is Region RTH Country TTAAii CCCC CodeForm 6 OFFENBACH GERMANY IUCX01 EDLR FM 94 XIII Additionally the GOME 2 MetOp NRT and OL including reprocessed products in HDEF5 format are available at the DLR atmos FTP server ftp atmos caf dlr de gome2nrt ftp atmos caf dlr de gome2nt ftp atmos caf dlr de gome2ol The products are organized in directories YYYY MM DD where YYYY is the year MM the month DD the day On request the NRT and OL products are directly pushed to dedicated FTP servers located at the user s premises Following the O3M SAF strategy reprocessed products replace off line products in the local archive and FTP server The reasoning behind is that the reprocessed products are the best possible products and their quality is at least as good as the off line products 21 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 22 of 47 5 9 Product Ordering 5 9 1 GOME ERS 2 GOME ERS 2 total column products are generated at DLR s D PAF on behalf of ESA For ordering registration pleasecontact ESA ESRIN EO Help Desk eohelp esa int Current and historical quicklook image
50. sas well as value added products generated by DLR are available at http atmos caf dlr de gome 5 9 2 GOME 2 MetOp The GOME 2 MetOp total column products are generated at DLR in the framework of 03M SAF For information and accessto all O3M SAF products please refer to the O3M SAF web page and help desk O3M SAF Web page http o3msaf fmi fi O3M SAF Helpdesk o3msaf Qfmi fi Additional information can be found in EUMETSAT s product Navigator accessible through the following link http navigator eumetsat int Current and historical quicklook imagesas well as value added products generated by DLR are available at http atmos caf dlr de gome2 22 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 23 of 47 19 February 2010 6 HDF5 Product Format Description The product content comprisesthe following groups META_DATA e Product Metadata GEOLOCATION e Date amp Time all retrievals e A Corner Coordinates amp Centre of Ground Pixel e Solar Line of Sight Zenith and relative Azimuth anglesat TOA e Orbit information TOTAL COLUMNS e Total and tropospheric column amounts of the various trace gases with corresponding relative errors CLOUD PROPERTIES e Retrieved cloud properties DETAILED RESULTS e Geophysical parameters surface cloud and aerosol values e Vertical column slant column
51. t figure shows a schematic representation of GOME optical layout A scan mirror 26 directs the light emitted from the Earth s atmosphere or the Sun diffuser 24 into the instrument The spectrometer splits incoming light into four channels 11 12 18 19 using a complex array of telescopes 5 25 prisms 4 6 and gratings 8 9 20 21 Detectors at the end of each optical path 13 to 16 collect information about the signal in each channel t Figure 1 GOME optical layout courtesy of ESA ESTEC zd s DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 12 of 47 2 2 GOME ERS 2 In June 1990 the ESA Council approved the satellite project to follow the first European Remote Sensing Satellite ERS 1 The ERS 2 satellite was intended to provide data continuity between ERS 1 and the European polar platforms ERS 2 was launched on 21 April 1995 In addition to the ERS 1 mission objectives ERS 2 was scheduled to make a significant contribution to atmospheric chemistry To meet this need ERS 2 carried GOME an instrument designed to measure a range of atmospheric trace constituents in the troposphere and stratosphere GOME ERS 2 is a nadir viewing spectrometer which in its normal mode scans across track in three steps The field of view of each step may be varied in size from 40 km x 40
52. t server architecture which makes it possible to run the system with an unlimited number of processing nodes The average UPAS processing time for O NO and cloud retrieval includes 15 on pre processing tasks 15 on DOAS 60 on explicit calls to the radiative transfer model LIDORT for AMF calculations and the rest on Level 1 loading and other tasks The reprocessing of one year of GOME ERS 2 data can be done in just one day using 10 processing cores 4 1 GOME ERS 2 DLR hasa processing chain for GOME ERS 2 NRT and OL total column products that is being used operationally since 1995 It includes data ingestion from level 1 to level 4 product generation quality control product archiving data dissemination and ordering 4 2 GOME 2 MetOp DLR has developed the operational processing chain for GOME 2 MetOp total column products The level 1b products are generated at the EPS ground segment in EUMETSAT R6 and received at DLR via EUMETCast DLR generates GOME 2 MetOp level 2 total column and cloud products using UPAS There are different modules for quality control and monitoring production control archiving and order handling The level 2 products generated at DLR are validated on a regular basis by the O3M SAF partner institutes AUTH BIRA and FMI The GOME 2 MetOp level 2 NRT products are disseminated primary with EUMETCast WMO GTS and internet The off line products are disseminated via Internet and media The ordering of produc
53. t values are available in the dataset PlumeHeigths Attribute Name Data Type Unit Description NumberOfPlumeHeights integer Number of assumed plume heights DatasetName Data Type Unit Description PlumeHeights float heights km Assumed plume heights for retrieval ESCCorrected float pixels heights mol cm Slant column density background corrected AMF Clear float pixels heights AMF to ground AMFClear_Error float pixels heights Error on AMF to ground AMFCloud float pixels heights AMF to cloud top 1 if clear sky AMFCloud_Error float pixels heights Error on AMF to cloud top 1 if clear sky AMF Total float pixels heights Total AMF AMFTotal Error float pixels heights Total AMF error VCDCorrected float pixels heights mol cm Total vertical column density background corrected VCDCorrected_Error float pixels heights a Error on total vertical column density SO2_Flag integer pixels 7 Flag indexing SO2 calculations see 6 7 4 on page 37 6 6 4 DETAILED_RESULTS H2O Subgroup DatasetName Data Type Unit Description ESC_O2 float pixels mol cm effective O2 slant column ESC O4 float pixels mol cr effective O4 slant column RingCorrectionFactor float pixels RingCorrectionFactor H20O Flag integer pixels Flag indexing H20 calculations see 6 7 5 on page 37 6 6 5 DETAILED_RESULTS HCHO Subgroup
54. tal Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 38 of 47 1 2 Cloudyconditions e reduced quality of HCHO total column Note CloudFraction gt 40 2 4 HCHO column data not available e HCHO contains fill values 38 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 39 of 47 19 February 2010 7 BUFR Product Format Description 7 1 Structure The data in the BUFR file is organized in six sections INDICATOR SECTION IDENTIFICATION OPTIONAL SECTION DATA DESCRIPTION DATA SECTION and END SECTION The values in all sections are either copied from the level 1 R4 R5 or other input data or calculated by the level 1 to 2 processor Each of the sections of a BUFR messageis made up of a series of octets The term octet meaning 8 bits was coinedto avoid having to continually qualify byte as an 8 bit byte The DATA DESCRIPTION section contains a list of descriptors defining the structure and the format of data following in DATA SECTION This is called self descriptive nature of BUFR The strength of this self descriptive feature is in accommodating change For example if new observations or observational platforms are developed there is no needto invent a new code form to represent and transmit the new dat
55. toring one message The file contains the information corresponding to a single orbit can contain unlimited number of consecutive BUFR messages 7 2 WMO GTS Bulletin Identifier The BUFR products from the O3M SAF can be accessedusing the following identifier Region RTH Country TTAAii CCCC CodeForm 6 OFFENBACH GERMANY TUCX01 EDLR FM 94 XIII 39 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H2O HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 40 of 47 7 3 SectionO Indicator Section Octet Description Allowed Values 1 4 BUFR coded according to the CCITT International Alphabet No 5 BUFR 5 7 Total length of BUFR message in octets including Section 0 0 15000 8 BUFR edition number currently 4 1 4 7 4 Section1 Identification Section Um Allowed Used Octet Description Values 1 3 Length of section in octets int value 4 BUFR master table zero if standard WMO FM 94 BUFR tables are used provides 0 for BUFR to be used to represent data from other disciplines and with their own versions of master tables and local tables 5 6 Originating centre code table 0 01 031 210 7 8 Originating sub centre 0 9 Update sequence number zero for original BUFR messages incremented for updates 1 10 Bit 1 0 No optional section 1
56. ts can be done via dedicated user services The GOME 2 MetOp level 1 products are delivered in NRT approx 1 45 hours after sensing to the user community via EUMETCast The NRT level 1 products are delivered in so called PDU files product dissemination unit containing 3 minutes of measurements The ground segment at DLR needs less than 15 minutes for acquiring the input data retrieving the trace gastotal columns and disseminating the resulting products Figure 2 that meansthe GOME 2 MetOp total column products are available to the users in less than 2 hours after sensing The GOME 2 MetOp operational systemfor NRT processing comprisestwo 64 bit Linux PCs under a high reliability configuration and several double dual core 64 bit Linux PCs for OL processing and reprocessing 15 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 16 of 47 Broadcast Online and Offline and Delivery Internet 1 1 EumetCas t Receiving cows f i Prod Libran malons Assimilatio Z F eu EE L2 GOME L2 is Figure 2 GOME 2 MetOp processing chain 4 3 Data Management The processing of GOME 2 MetOp data is embedded in DLR s multi mission facility ensuring high availability and sustainability The German National Remote Sensing Data Library stores the data for the long term enabling
57. uration of the product in minutes e MISSION denotesthe mission ERS2 METOPA METOPB METOPC e 4 is the five digit orbit number e PRO is the processing center i e DLR e RV is the two digit product revision e TYPE denotesthe product format used HDF5 or BUFR For example the following identifier denotesa GOME ERS 2 off line product GOME O3 NO2 L2 20060723165752 023 ERS2 58855 DLR 05 HDF5 Thefollowing exampleis a valid namefor a GOME 2 MetOp off line product GOME O3 NO2 BrO L2 20070302111155 047 METOPA 01900 DLR 01 HDF5 Note The GOME 2 MetOp NRT products disseminated via EUMET Cast have a fixed prefix file name S O3M seethe following example S O3M GOME O3 L2 20070302111155 003 METOPA 01900 DLR 01 BUFR 20 Product User Manual for GOME Total Columns of Ozone NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 DLR GOME PUM 01 and Cloud Properties Iss Rev 2 C DLR Page 21 of 47 19 February 2010 5 8 Product Dissemination 5 8 1 GOME ERS 2 GOME ERS 2 products are available at the D PAF FTP server ftp ops de envisat esa int The OL products are organizedin directories as follows products level 2 HDF5 YYYY MM DD where YYYY is the year MM the month DD the day The NRT products are available in the above D PAF FTP server and are organized in the sameway asthe off line products but they are located in the directory nrt products 5 8 2 GOME 2 MetOp The primary dissemination mean of GOME 2 MetOp NRT product
58. values are nevertheless available in the DETAILED_RESULTSgroup under the VCD entry The BUFR products contain all H20 retrievals but it is recoomended not to use measurements under cloudy conditions cloud fraction cloud top albedo lt 0 6 8 1 ConfidenceFlagsand Ancillary Fields The users should check the quality flags associated with each trace gas and cloud product Detailed information is given in the corresponding tables 8 2 Software and Toolsfor readingthe products The HDF5 products can be read using the standard HDF software and tools available at http www hdfgroup org products hdf5 tools the above Web page contains also HDF5 libraries that can be used with a number of programming languages The BEAT and VISAN tools for ingesting processing and analyzing atmospheric remote sensing data fully support the GOME HDF5 products http www stcorp nl beat ECMWF provides software for decoding BUFR products see http www ecmwf int products data software bufr html 43 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 C NO2 SO2 BrO H20 HCHO OCIO tropospheric NO2 19 February 2010 and Cloud Properties DLR Page 44 of 47 A Appendixes A 1 HDF5 Data Types The following table shows the correspondence between Product data types and HDF5 data types Data type HDF5 predefined data type char H5T_STD_I8LE integer H5T STD I32LE float H5T IEEE F32LE double H5T I
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