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DLR GOME Product User Manual

1. Dataset Name Data Type Unit Description ESCCorrected float pixels mol cm Slant column density background corrected ESCRefSector float pixels mol cm Slant column density for Reference Sector Pacific Region between 160 240 E ESCRefSectorEquator float pixels mol cm Slant column density for the Equatorial Reference Sector Pacific Equator Region VCDO float pixels mol cm A priori vertical column density for the Reference Sector Pacific Region 160 240 E from IMAGES model VCDCorrected float pixels mol cm Total vertical column density background corrected HCHO_Flag integer pixels Flag indexing HCHO calculations see 6 8 7 on page 41 37 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 38 of 49 DLR 6 7 DETAILED_RESULTS_GODFIT Group As the GDP 5 algorithm is different to GDP 4 an additional output section was introduced for each trace gas processed with GDP 5 For Os DETAILED_RESULTS_GODFIT O3 it contains the following datasets layers 13 Dataset Name Data Type Unit Description O3Profile float pixels layers DU A priori O profile used in the retrieval of O TemperatureProfile float pixels layers K A priori temperature profile used in the retrieval of O FitParl O3 float p
2. DETAILED RESULTS ESC 01 2 N 1 O3 O3Temperature 0 1 2 N Figure 4 Organization of the GOME total column products in the HDF5 structure Most dataset are one dimensional containing one value for every ground pixel In the DETAILED_RESULTS group however every dataset contains an additional dimension 206s Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties Page 27 of 49 DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 DLR for the fitting window In the subgroups of detailed results the dimensions of the datasets vary considerably beeing one dimensional ground pixel number only over two dimensional O3 TemperatureProfile containing one profile for every ground pixel to three dimensional for O3 AveragingKernels or there are even be subgroups e g for the different plume heights of SO 6 1 1 Description of Common Items In the GEOLOCATION and TOTAL COLUMN groups all datasets have a set of attached attributes These are 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 Minimu
3. 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 see table below 0 08 044 CAS registry number see table below 0 15 021 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 Defined by local Generating Centre 1 0 08 023 First order statistics 7 Mean absolute error 0 31 001 Delayed descriptor replication factor 2 0 15 021 Scaled Integrated mass density kg m 44 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR and Cloud Properties Page 45 of 49 DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 7 7 Section 4 Indicator section Octet Description Allowed Values 1 3 Length of section in octets 4 Set to zero reserved 5 Binary data as defined by descriptors which begin at octet 8 Section 3 7 8 Section 5 End Section Octet Description Allowed Values 1 4 7777 coded according to the CCITT Int
4. DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 4 of 49 DLR 2 C 23 April 2010 1 1 Add reference to reprocessed GOME 2 5 9 2 Add new O3M SAF logo and web page 6 4 Finalized NO2 HDES entries 6 2 Added PMD dataset descriptions 7 2 Add WMO GTS bulletin identifier 8 New section 6 8 5 New flag value added to SO2_Flag 6 8 7 New flag value added to HCHO Flag 2 D 25 March 2011 16 8 2 Renamed SurfaceCondition_Flag to SurfaceConditionFlags 6 2 Removed obsolete FittingFlag AMFFlag and VCDFlag 6 8 6 New definitions for H2O_Flags 6 3 Converted ViewMode to integer and added DescendingFlag 2 E 8 August 2012 14 1 Added new chapter GDP 5 0 used for 6 7 GOME ERS 2 O products Added CHOCHO entries for future use globally 6 6 2 Added NO entries AMF Tropo Error field AMF Tropo To Ground Error field AMF Tropo To Cloud Error field VCD Corrected Error field VCD Strato Error field Averaging Kernel field Averaging Kernel Pressure field 5 December 2012 15 7 Updated file name examples 2 F 28 June 2013 6 6 4 H O Add EastWestPostCorrectionFactorH20 Removed RingCorrectionFactor 6 8 1 Added ViewMode description table all Updates for GOME 2 MetOp B Updated entry descriptions Various clarifications Product User Manual for GOME Total Columns of
5. e DETAILED RESULTS NO2 VCDCorrected contains the pollution corrected total column density e DETAILED RESULTS NO2 VCDTropo contains the tropospheric column density Note IntensityWeightedCloudFraction 5096 Unpolluted condition VCDTropo and VCDCorrected not available fill values e DETAILED RESULTS VCD contains the total column density based on an unpolluted AMF initial total VCD Note IntensityWeightedCloudFraction lt 50 Cloudy condition VCDTropo and VCDCorrected not available fill values e DETAILED RESULTS VCD contains the total column density based on an unpolluted AMF initial total VCD Note IntensityWeightedCloudFraction gt 50 Measurement in polar regions Lat gt 70 deg VCDTropo and VCDCorrected not available fill values e DETAILED RESULTS VCD contains the total column density based on an unpolluted AMF initial total VCD 16 NO2 column data not available e VCD VCDTropo and VCDCorrected contain fill values e TOTAL COLUMNS NO 2 contain fill values For more information on the NO2 parameters see Section 8 6 8 5 SO2 Flags Flag Value Description 0 1 Measurement in polar regions SZA gt 75 deg e reduced quality of SO2 total column 1 2 SO2 column data not available e DETAILED RESULTS VCD and DETAILED RESULTS SO2 VCDCorrected contain fill values e TOTAL COLUMNS SO2 contain fill values 2 4 SO2 column data not available due to unfulfilled ex
6. SO2 H20 HCHO OCIO and Cloud Properties Page 43 of 49 DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 7 3 Section 0 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 Section 1 Identification Section Octet Description TONE Values 1 3 Length of section in octets int value 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 Optional section included Bits 2 8 set to zero reserved 0 11 Data Category type BUFR Table A 3 12 Data Category sub type 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 Section 3 Indi
7. 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 PAF DLR OP 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 for string string reprocessing part of logical product identifier ProductType string Description of the product type ERSNTO O3MNTO ERSOTO O3MOTO 28 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties DLR Page 29 of 49 DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 Allowed Attribute Name Data Type Description Typ P Values ProcessingLevel 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 pr
8. 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 332 0 359 0 SO column 315 0 326 0 H O column 614 0 683 2 HCHO column 328 5 346 0 Cloud fraction 300 800 PMD p Cloud top height pressure and 758 0 771 0 albedo cloud optical thickness 15 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 16 of 49 DLR 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 2 and GOME 2 MetOp and produces total columns of trace gases e g O NO BrO H O SO HCHO and cloud properties cloud fraction cloud top albedo and height The UPAS system is based on a scalable client 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
9. 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 4 1 GOME ERS 2 DLR has a 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 The operational products from GOME are total ozone and NO using GDP 5 0 In GDP 5 0 the new GODFIT algorithm for total ozone developed by BIRA RTS DLR and the DOAS algorithm for NO are used See R2 and R3 GOME ERS 2 images and value added products produced at DLR are available at http atmos eoc dlr de gome 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 R13 and received at DLR via EUMETCast R16 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 Inter
10. 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 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 available and disseminated to the users two weeks up to four weeks in case of GOME ERS 2 after sensing Additionally DLR provides reprocessed products for climate applications The complete sF DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 8 of 49 DLR GOME ERS 2 data record starting in 1995 has been reprocessed and validated on a regular basis using improved algorithms In the same way the complete GOME 2 MetOp data record starting in 2007 was already reprocessed and validated GOME ERS 2 GOME 2 MetOp A and GOME 2 MetOp B 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 pro
11. tools available at http www hdfgroup org products hdf5 tools the above Web page contains HDF5 libraries for 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 ECMWFE provides software for decoding BUFR products see http www ecmwf int products data software bufr html 46 Product User Manual for GOME Total Columns of Ozone DLR GOME PUM 01 NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 47 of 49 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 IEEE F64LE string H5T C S1 UTC H5T COMPOUND H5T STD I32LE Day H5T STD I32LE MillisecondOfDay h 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 charact
12. 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 HDF5 format are available at the DLR atmos FTP server ftp atmos eoc dlr de gome2nrt ftp atmos eoc dlr de gome2nt ftp atmos eoc dlr de gome2ol The products are organized in directories YYYY MM DD where YYYY is the year MM the month DD the day For requesting a FTP user account see 5 9 2 Additionally the NRT and OL products can be 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 22 Product User Manual for GOME Total Columns of Ozone DLR GOME PUM 01 NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 23 of 49 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 cesa For ordering registration please contact ESA ESRIN EO Help Desk eohelp esa int Current and historical quicklook images as well as value added products generated by DLR are availa
13. 00 10 Set if the total column mol cm retrieved for this ground pixel is outside the specified range 2 4 Large error in slant lt 2 lt 50 lt 100 Not lt 50 Not Not column ESC applicable Set if the ESC_Error value of this ground pixel exceeds the specified threshold applicable applicable 39 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 40 of 49 DLR 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 0 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 exceeds a specific threshold flag 2 is set See VCDQualityIndicator in 6 2 on page 28 for the percentage of pixels which have been flagged as an overall quality indicator for the whole orbit 6 8 4 NO2Tropo Flags Flag Value Description 0 1 Polluted condition VCDTropo and VCDCorrected values are available e DETAILED RESULTS VCD contains the total column density based on an unpolluted AMF initial total VCD
14. 1 Iss Rev 2 F and Cloud Properties 28 June 2013 Page 11 of 49 1 3 Abbreviations and 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 Technology 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 used for off line total column and cloud products Product Dissemination Unit Polarisation Measurement Device Postfix identifier use
15. 2 H20 HCHO OCIO and Cloud Properties Page 35 of 49 DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 DLR 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 26 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 tables Dataset Name 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 SurfaceConditionFlags integer pixels Flag for different pixel retrieval conditions e g land sea sun glint or snow ice see 6 8 2 SurfaceAlbedo float pixels windows Surface albedo for the associated retrieval window QualityFlags integer pixels windows Quality flags for each pixel gas see 6 8 3 VCD float pixels windows mol cm Uncorrected vertical column density of main gas VCD Error float pixels windows Error on vertical column density IntensityWeightedCloudFraction float pixels windows Cloud radiance fraction weighting factor
16. CDTropo float pixels mol cm Tropospheric vertical column density cloud screened VCDTropo_Error float pixels Error on tropospheric vertical column density VCDCorrected float pixels mol cm Total vertical column density corrected for tropospheric contribution cloud screened VCDCorrected_Error float pixels Error on corrected total vertical column density NO2Tropo_Flag integer pixels Flag indexing tropospheric NO2 calculations see 6 8 4 on page 40 AveragingKernel float pixels Average Kernel for tropospheric NO2 layers 24 layers AveragingKernelPressureLevel Pressure levels of Average Kernel layers 24 ayers Please note that this section is empty for GOME ERS 2 products For more information on the NO2 parameters see section 8 36 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties DLR Page 37 of 49 DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 6 6 3 DETAILED RESULTS SO2 Subgroup The GOME SO2 algorithm provides SO2 vertical columns for several assumed plume heights The number of plume heights is available in the field NumberOfPlumeHeights which also describes the cardinality of the subsequent datasets denoted as heights The different height values are available in the dataset PlumeHeights Attribute Name Data Type Unit
17. CLOUD_PROPERTIES e Retrieved cloud properties e DETAILED_RESULTS e Geophysical parameters surface cloud and aerosol values e Vertical column slant column and AMF values with corresponding errors e Fitting diagnostics chi square RMS etc e Various subgroups for trace gas specific data e g O3 NO2 SO2 etc 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 R11 R12 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 as a matrix Elements in these matrices are not always at
18. Cloud Products ecce 19 5L OU OS ecd ne tA Ent EE ia RS 19 5 2 Geographical Coverage and Granularity seen 19 53 Spatial Response are te Eod come aem Mte dus 19 5 4 Delivery FINE e 20 5 5 Expected ACCUTACY eie tobson tone tice ne ee ka een ee 20 5 6 Produet Formats ee o tre ae een nce nei Pel 21 5 7 Flle Name te S M 21 5 8 Product Dssemmt n yes 22 5 8 1 GOME ERS t 22 5 8 2G OME 2 MEIOD een 22 5 9 Product Ordr ne le 23 59 GONE ERS esse un ee 23 5 9 2 GOME 2 MetOp anne ein 24 6 HDF5 Product Format Description ssssssssossssnsssnsssonssnnssssnssnnsssnssnsnsnnsnsnnnnsnsnnnnene 25 6 1 SECHICCHTO uoi ed I Hier lege 25 6 1 1 Description of Common Items neu de 27 6 2 META DATA GW ee anerkennt 28 63 GEOLOCATION GEOBD en decr rise oec EOM el xa Tee hiatus 31 6 4 TOTAL COLUMNS CITOUD rear 33 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 6 of 49 DLR 6 5 CLOUD PROPERTIES Grolp use 34 GO DELAILED RESULTS Group La ee ee usa 35 6 6 1 DETAILED RESULTS O3 Subgroup sees eene 36 6 6 2 DETAILED RESULTS N 2 Subgroup ur 36 6 6 3 DETAILED_RESULTS SO2 Subgroup eeeseesssesssensssessnennnnennnennnnnnnnennnnn 37 6 6 4 DETAILED RESULTS H2Q Subsrmp un aenenenen ne 37 6 6 5 DETAILE
19. D RESULTS HCHO Subgroup eene 37 6 7 DETAILED_RESULTS_GODFIT Group na nr 38 6 8 Detailed Fla8 Description una 39 6 8 1 VIEW Mode er ee ER a cee eat ue 39 6 8 2 Surface onditionklaes 22m m ses peste ema a EE Red 39 6 8 3 C alibyP gs a oed vin ppt epe rbi Une oret A RI SUN 39 56 8 1 NOD TropO Elagsc een endi Ine RM 40 68 3502 Rla8 MP MTS 40 OBO Hass an ie E ERIS 41 6 8 7 HGHO EDS readers Baier 41 7 BUFR Product Format Description 4 eee eee e eese eene eene eene ense tn esee tn as etnun 42 Trg STUCUEE C D EN EN 42 7 2 WMO GTS Bulletin Identifier 4 2a Haken 42 7 3 Section D Indicator Section Rund 43 7 4 Section 1 Identification Section eee eee eene eene tn netten tnnt tne 43 7 5 Section 3 Indicator Section reete teet euren 43 7 6 Section 3 UPAS Level 2 Specific List of Descriptors esee 44 7 7 Section 4 Indicator Sectioni u oerte enti o ee eee cc 45 7 8 Section oc End Sectio alla 45 7 9 Trace Gas Table ae 45 8 Using the PrOUUCIS occas eere ms erro ibd oRe aoa Poe eB savastewadenasnsbecasoeeusdoasosdvaieesraerdsvessvisseusadions 46 8 1 Confidence Flags and Ancillary Fields sese 46 8 2 Software and Tools for reading the products esee 46 AA PPO in OSs iieri iri CUL rp CHART HUE SER RUE LEE CURIAE RET RA RERO ICa REN LAU I D Er ER VE EOS 47 AST HIDE Data Vy Pes yes nie eade te
20. DLR Product User Manual for GOME Total Columns of Ozone NO tropospheric NO BrO SO HO HCHO OCIO and Cloud Properties O3M SAF OTO and NTO Dobson Units 200 300 400 Doc No DLR GOME PUM 01 Iss Rev 2 F Date 28 June 2013 Deutsches Zentrum f r Luft und Raumfahrt e V DLR Oberpfaffenhofen Germany DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 2 of 49 DLR Signatures Action Name Affiliation Function Date Signature prepared by P Valks DLR MF O3MSAF Project Manager D Loyola R DLR MF W Zimmer DLR MF S Kiemle DLR DFD GOME Project Manager GOME Project Engineer DIMS Project Manager 28 June 2013 N Hao DLR MF GOME Project Scientist P Hedelt DLR MF GOME Project Scientist M Grossi DLR MF GOME Project Scientist M Pedergnana DLR MF GOME Project Engineer H O HCHO by former S Emmadi DLR MF GOME Project Engineer March 2011 BUFR v3 by former L Butenko DLR MF GOME Project Engineer 14 June 2006 HDF5 by former Y Livschitz DLR MF GOME Project Engineer EON Mt released by P Valks DLR MF O3MSAF Project Manager 9 June 2013 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 vario
21. Description NumberOfPlumeHeights integer Number of assumed plume heights 3 Dataset Name Data Type Unit Description PlumeHeights float heights km Assumed plume heights for retrieval 15 6 2 5 km ESCCorrected float pixels heights mol cm SO2 slant column density background corrected AMFToGround float pixels heights AME to ground AMFToGround_Error float pixels heights Error on AMF to ground AMFToCloudTop float pixels heights AMF to cloud top 1 if clear sky AMFToCloudTop Error float pixels heights Error on AMF to cloud top 1 if clear sky AMFTotal 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 Error on total vertical column density SO2_Flag integer pixels z Flag indexing SO2 calculations see 6 8 5 on page 40 for future use not yet implemented 6 6 4 DETAILED_RESULTS H20 Subgroup Dataset Name Data Type Unit Description ESC_O2 float pixels mol cm O2 slant column density ESC_O4 float pixels mol cm 04 slant column density EastWestPostCorrectionFactorH2O float pixels Correction factor for scan angle dependency in retrieved H2O column H20 Flag integer pixels Flag indexing H2O calculations see 6 8 6 on page 41 6 6 5 DETAILED RESULTS HCHO Subgroup
22. IO and Cloud Properties Page 42 of 49 DLR 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 R11 R12 or other input data or calculated by the level 1 to 2 processor Each of the sections of a BUFR message is made up of a series of octets The term octet meaning 8 bits was coined to 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 need to invent a new code form to represent and transmit the new data 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 message and 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 d
23. LR 1 45 hours after sensing then the GOME total column products will be disseminated to the users in less than 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 Reprocessed GOME ERS 2 and GOME 2 MetOp level 2 products using the latest level 1 data and improved retrieval algorithms are available on a regular basis 5 5 Expected Accuracy The following table lists the GOME total column trace gases and cloud products provided by DLR together with estimated uncertainties Product Acronym Expected Accuracy Expected Precision 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 9 80 lt SZA lt 90 see R4 and R5 Total NO column NO2 5 15 unpolluted 3 15 unpolluted conditions see R6 conditions Tropospheric NO column NO2Tropo 40 80 polluted conditions 40 8096 polluted conditions gt 100 unpolluted gt 100 unpolluted see R6 Total BrO column BrO 20 50 see R8 10 50 Total SO column SO2 50 10096 SZA 70 20 5096 SZA 70 710096 SZA gt 70 see R7 5096 SZA gt 70 Total H O column H20 10 2596 see R9 5 20 Total HCHO column HCHO 50 100 polluted 20 50 polluted conditions conditions gt 100 unpollu
24. OAS 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 ahead for the MetOp Programme The instruments on the MetOp satellites are designed to 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 A second polar orbiting meteorological satellite in the series Metop B was successfully launched on 17 September 2012 The GOME 2 MetOp field of view of each step may be varied 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 R13 Based on the successfully work with the GOME Data Proces
25. OR eR eoe qn edes ts 47 A 2 Traceability Matrix of HDF5 Metadata to EECF Parameters 48 A 3 Traceability Matrix of HDF5 Metadata to UMARF Parameters 49 Product User Manual for GOME Total Columns of Ozone DLR GOME PUM 01 NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 7 of 49 1 Introduction 1 1 Purpose and 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 produces total column trace gases and cloud products for GOME 2 MetOp in the framework of EUMETSAT s O3M SAF DLR has a 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 manual 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 applies to both sensors The trace gases total column products are e Ozone O column e Nitrogen dioxide NO column e Bromide monoxide BrO column e Sulphur dioxide SO column e Water vapour H O column Formaldehyde HCHO column Additionally DLR provides
26. OVERAGE STOP SensingEndTime SOFTWARE VERSION ProductAlgorithmVersion AUX DATA InitializationFileVersion PRODUCT TYPE ProcessingLevel 02 or 03 REVISION Revision SOURCE ITEM BaseProducts 48 Product User Manual for GOME Total Columns of Ozone DLR GOME PUM 01 NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 49 of 49 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 parameters to product file attributes is shown below again attributes can only take values allowed by UMARF ae M Attribute Name Notes AARF ArchiveFacility possible values D PAF DLR OP ERS O3DLR METOP ABID ProductContents Spectral Band Ids AIID InstrumentID GOME APAS Applicable Product Size APNA Applicable Product Name APNM ProductType e g O3MOTO O3MNTO APPN BaseProducts Parent Product Name ASTI SatelliteID possible values ERS M01 M02 M03 for METOP AVBA BaseProductAlgorithmVersion AVPA ProductAlgorithmVersion Concatenation of the HDF5 attributes ProductAlgorithmVersion InitializationFileVersion InternalProcessorRevision and Revision GDMD Applicable Disposition Mod
27. Ozone DLR GOME PUM 01 NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 5 of 49 Table of Contents T Miroductionn susanne 7 TL PURPOSE and SC0p EEE E UE end RI 7 V2 References den 9 1 2 1 Applicable Doeiments asia ak 9 142 1 Reference DOGUBGHIS nn nee EAT 9 1 3 Abbreviations and Acronyms uu iesiesiuneseenelelntuuleken ne 11 2 GOME Instrumnen sicsidssstsaacieecgeasiacctovenssocvssunaseascuoaccessuas QUAS PER LS QUERENS OR TVA NE 12 2 1 Introduction ses races caves cases ek 12 22 GOMEBE BERS ova sauer 13 2 3 GOME 2 MelOR 2 22 20 13 2 4 Measurement Scenarios Timelines and Instrument Modes 14 3 Aleornhim Descriptln eii cuasdevsivadesccassabosestodlscsausvonssidedacsdapardevadiaiusdeessvinssdusaeiebs 15 Sb SUMMA na er tuc pt i Roc RUTILIUS Er Pe Aud 15 3 2 Trace Gas and Cloud Products ccsscsssscssscccsssesscsssccessccensseeseceseseceesesncessrsnes 15 A gt PEOCESSIIO cendo casei o EEEHR e ger eRBELH IR TE ERE ERR PIE EAU EIN EVE EUR CU va 16 JI GONIE BRS 2 itor uai sedata eii RM em IM NOB I e US 16 4 2 GOME 2 M6tOD norn utet mu e dtes Oi ec taco ote n eR Dr eden ame 16 4 3 Data Management taten need 17 4 4 Quality Control and Monitoring eee eese eee eee einen rnnetnnntnne einen nnn 17 4 5 Geophysical V alldattOn na ea een 18 AIG User SOL VICES MEN ERR 18 5 Total Column Trace Gases and
28. ata encoded in BUFR format is purely binary or bit oriented thus making it both machine dependent and at the same time machine independent The dependency comes in 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 messages are restricted to 15000 octets or 120000 bits This limit is to allow an entire BUFR message to 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 message is limited to 200 ground pixels that gives approximately 10Kbytes for storing one message The file contains the information corresponding to a single orbit and can contain an unlimited number of consecutive BUFR messages 7 2 WMO GTS Bulletin Identifier The BUFR products from the O3M SAF can be accessed using the following identifier Region RTH Country TTAAii CCCC CodeForm 6 OFFENBACH GERMANY IUCX01 EDLR FM 94 XIII 42 DLR Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO
29. bal coverage at the equator after three days GOME 2 MetOp has a daily near 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 reprocessed products 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 and 8 back scan pixels with a nominal resolution of 40 km x 240 km Both forward and back scan pixels are generally processed and written to the products 19 DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties Page 20 of 49 DLR 5 4 Delivery Time DLR generates near real time NRT off line OL and reprocessed products RP The 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 D
30. ble at http atmos eoc dlr de gome Ir DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 24 of 49 DLR 5 9 2 GOME 2 MetOp The GOME 2 MetOp total column products are generated at DLR in the framework of EUMETSAT s O3M SAF O3M SAF For information and access to 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 fmi fi Additional information can be found in EUMETSAT s product Navigator accessible through the following link http navigator eumetsat int Current and historical quicklook images as well as value added products generated by DLR are available at http atmos eoc dlr de gome2 24 Product User Manual for GOME Total Columns of Ozone DLR GOME PUM 01 NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 25 of 49 6 HDF5 Product Format Description The product content comprises the following groups e META_DATA e Product Metadata e 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 angles at TOA e Orbit information e TOTAL_COLUMNS e Total and tropospheric column amounts of the various trace gases with corresponding relative errors e
31. c NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties Page 32 of 49 DLR The data sets inthe 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 of the observation in UTC format LongitudeCentre float pixels degrees Longitude of the centre of the ground pixel Point F LatitudeCentre float pixels degrees Latitude of the centre of the ground pixel Point F LongitudeA float pixels degrees Longitude Point A LatitudeA float pixels degrees Latitude Point A LongitudeB float pixels degrees Longitude Point B LatitudeB float pixels degrees Latitude Point B LongitudeC float pixels degrees Longitude Point C LatitudeC float pixels degrees Latitude Point C LongitudeD float pixels degrees Longitude Point D LatitudeD float pixels degrees Latitude Point D PMDCenterLon float PMDpixels degrees Longitude Point F of forward scan PMD subpixel center PMDCenterLat float PMDpixels degrees Latitude Point F of forward scan PMD subpixel center PMDPixelMap integer pixels Mapping from ground pixel to PMD pixel 1 for backscan SolarZenithAngleE float pixels degrees Solar zenith angle at TOA Point E SolarZenithAngleCentre float pixels degrees Solar ze
32. cator Section Octet Description aloe CE 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 compressed data 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 43 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 44 of 49 DLR 7 6 Section 3 UPAS Level 2 Specific List of Descriptors Descriptor Description Value 0 01 007 Satellite Identifier 5 Metop 2 0 02 019 Satellite Instruments 220 GOME 2 301011 Date in format YYY Y MM DD 0 04 001 0 04 002 0 04 003 3 01 013 Time in format HH MM SS 0 04 004 0 04 005 0 04 006 301 021 Latitude Longitude Centre 0 05 001 0 06 001 102 004 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 Sun to satellite azimuth difference 0 20 010 Cloud Cover Total 96 0 08 003 Vertical significance 2
33. ccomplished using ground based measurements available through the World Ozone and Ultraviolet 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 see section 5 9 4 6 User Services Information about data and services are accessible through the websites given in section 5 9 and at the end of this section The interactive catalogue and ordering interface EOWEB from DLR allows individual product searches and 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 eoc dlr de gome2 see Figure 3 GOME 2 MetOp A at DLR Mozilla Firefox lt 2 gt File Edit View History Bookmarks Tools Help gt o LU e http atmos caf d
34. cluded in the META_DATA MainSpecies attribute Dataset Name Data Type Unit Description 03 float pixels Dobson Units Total vertical column density of O3 O3_Error float pixels Error on total vertical column density of O3 NO2 float pixels molecules cm Initial total vertical column density of NO2 NO2_ Error float pixels Error on initial total vertical column density of NO2 NO2Tropo float pixels molecules cm Tropospheric vertical column density of NO2 cloud screened NO2Tropo_Error float pixels Error on tropospheric vertical column density of NO2 BrO float pixels molecules cm Vertical column density of BrO BrO Error float pixels 96 Error on vertical column density of BrO so2 float pixels Dobson Units Vertical column density of SO2 for a plume height of 6 km SO2 Error float pixels 96 Error on vertical column density of SO2 H20 float pixels kg m Vertical column density of H2O cloud screened H20 Error float pixels 96 Error on vertical column density of H2O HCHO float pixels molecules cm Vertical column density of HCHO cloud screened HCHO Error float pixels 96 Error on vertical column density of HCHO za DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 34 of 49 DLR 6 5 CLOUD_PROPERTIES Group In this group the
35. ducts 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 machine independent file formats commonly used for storage and transfer of scientific and meteorological data The present document is 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 gases total columns and cloud properties Summary of the processing steps e Product description including the used HDF5 and BUFR format Appendixes Product User Manual for GOME Total Columns of Ozone DLR GOME PUM 01 NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 9 of 49 1 2 References 1 2 1 Applicable Documents A1 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 UMAREF 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 1 Reference Document
36. e 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 RRCC 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 SSST SensingEndTime CCSDS date Parameter is not contained in the HDF5 product but will be provided by DIMS 49
37. e Data Type Unit Description ESCRingCorrected float pixels mol cm Ozone slant column density corrected for Ring effect O3Temperature float pixels K Fitted ozone temperature EastWestPostCorrection float pixels x Correction factor for scan angle dependency in retrieved Factor ozone column RingCorrection float pixels Ring correction factor O3Profile float pixels layers DU A priori O profile used in the retrieval of O layers 13 optional parameter TemperatureProfile float pixels layers K A priori temperature profile used in the retrieval of O layers 13 optional parameter Iterative VCDNumber Of integer pixels Iterations Number of iterations for the iterative VCD algorithm 6 6 2 DETAILED RESULTS NO2 Subgroup Dataset Name Data Type Unit Description AMFTropoToGround float pixels l Tropospheric AMF to ground clear sky AMFTropoToGround_Error float pixels Error on Tropospheric AMF to ground clear sky AMFTropoToCloudTop float pixels l Tropospheric AMF to cloud top 1 if clear sky AMFTropoToCloudTop_Error float pixels Error on tropospheric AMF to cloud top 1 if clear sky AMFTropo float pixels l Total tropospheric AMF AMFTropo_Error float pixels Error on total tropospheric AMF VCDStrato float pixels mol cm Stratospheric vertical column density VCDStrato_Error float pixels Error on stratospheric vertical column density V
38. els 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 BI DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties DLR Page 33 of 49 Dataset Name Data Type Unit Description IndexInScan integer pixels Index of the pixel within the scan 0 2 forward scan 0 east part of scan 1 centre part of scan 2 west part of scan 3 backward scan SubPixelInScan integer pixels Subpixel within the scan 0 3 for GOME ERS 2 0 to 3 7 or 31 for GOME 2 MetOp ViewMode integer pixels Scanning mode of the instrument at the time of acquisition bits 0 7 geolocation flags bit 8 31 See section 6 8 1 6 4 TOTAL COLUMNS Group The data sets in the TOTAL_COLUMNS group are given in the following tables Attributes attached 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 case it is in
39. er 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 Second in 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 F64LE Y H5T IEEE F64LE Z sl s DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties Page 48 of 49 DLR 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 HDFS file as attributes in the META_DATA group The tracing of EECF parameters to the attributes in the product file is indicated in the following table Attributes can only take values which are allowed by EECF EECF Short Name Attribute Name Notes SATELLITE_ID SatelliteID 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 D PAF DLR OP ERS O3DLR ArchiveFacility METOP PROCESSING DATE TIME ProcessingTime TEMPORAL COVERAGE START SensingStartTime TEMPORAL C
40. ernational Alphabet No 5 7777 7 9 Trace Gas Table The following field values are used for the different trace gases Trace gas Trace gas name Atmospheric Chemical No CAS Registry Number 08 043 descriptor 08 044 descriptor O Ozone 0 10028 15 6 NO Nitrogen dioxide 5 10102 44 0 BrO Bromine oxide 9 15656 19 6 SO Sulfur dioxide 8 7446 09 5 H O Water Vapour 1 7732 18 5 HCHO Formaldehyde 7 50 00 0 OCIO Chlorine dioxide 10 10049 04 4 CHOCHO Glyoxal TBD 107 22 2 45 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 46 of 49 DLR 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 H2O entry in the TOTAL_COLUMNS group of the HDF5 products is set to fill value for measurements under cloudy conditions The retrieval values are nevert
41. f 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 monitoring of global change and data reprocessing based on 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 and R17 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 processed orbit The quality control tool performs limit checks and computes some statistics to show the confidence levels of the product and its evolution within time 17 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 18 of 49 DLR 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 a
42. for clear sky and cloudy AMFs ESC float pixels windows mol cm Slant column density of main gas ESC Error float pixels windows Error on slant column density FittingRMS float pixels windows RMS of the DOAS fit FittingChiSquare float pixels windows ChiSquare of the DOAS fit FittingGoodness float pixels windows Goodness of the DOAS fit FittingNumberOflterations integer pixels windows Number of iterations in the DOAS fit GhostColumn float pixels windows mol cm Ghost column below cloud only used for O3 AMFToGround float pixels windows AMF to ground for main gas AMFToGround Error float pixels windows Error on AMF to ground AMFToCloudTop float pixels windows AMF to cloud top for main gas 1 if clear sky AMFToCloudTop Error float pixels windows Error on AMF to cloud top 1 if clear sky AMFTotal float pixels windows Total AMF for main gas AMFTotal Error float pixels windows Total AMF error The following subsections contain sub groups of the DETAILED RESULTS group which contain trace gas specific data sb DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 36 of 49 DLR 6 6 1 DETAILED_RESULTS O3 Subgroup In the following table the number of atmospheric layers is denoted as layers in profile datasets Dataset Nam
43. heless available in the DETAILED_RESULTS group under the VCD entry The BUFR products contain all H O retrievals but it is recommended not to use measurements under cloudy conditions cloud_fraction cloud_top_albedo lt 0 6 The NO2 entry in the TOTAL_COLUMNS group contains the same value as the VCD entry for the NO window in DETAILED_RESULTS These two entries contain the total NO column density based on an unpolluted AMF The VCDcorrected entry in DETAILED_RESULTS NO2 contains the pollution corrected total NO column density available only for measurements with an intensity weighted cloud fraction 5096 and for latitudes lt 70 deg Note that VCDcorrected gt VCD The NO2Tropo entry in the TOTAL COLUMNS group contains the same value as the VCDTropo entry in DETAILED RESULTS NO2 These two entries contain the tropospheric NO column density available only for measurements with an intensity weighted cloud fraction 5096 and for latitudes lt 70 deg The VCDStrato entry in DETAILED RESULTS NO2 contains the stratospheric NO column density as derived with a spatial filtering approach and available only for latitudes 70 deg 8 1 Confidence Flags and 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 Tools for reading the products The HDF5 products can be read using the standard HDF software and
44. hput 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 because of the higher data rate 10 times faster edd Product User Manual for GOME Total Columns of Ozone DLR GOME PUM 01 NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 15 of 49 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 GDP 4 7 uses an 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 The latest development GDP 5 uses the GODFIT algorithm for the retrieval of total ozone from GOME ERS 2 A detailed description of the GDP algorithms are given in R1 R2 and R3 3 2 Trace Gas and Cloud Products The GOME ERS 2 and GOME 2 MetOp trace gas column densities and cloud properties level 2 product are retrieved from GOME ir radiance and PMD data
45. ille K Clemer A Delcloo P Valks N Hao GOME 2 NO total column validation report SAF O3M IASB VR NO2 095 February 2011 R7 J van Geffen M Van Roozendael M Rix P Valks GOME 2 SO total column initial validation TN IASB GOME2 O3MSAF SO2 01 1 November 2008 R8 M Van Roozendael N Theys N Hao P Valks GOME 2 BrO total column validation report SAF O3M BIRA VR BRO 091 January 2009 R9 N Kalakoski T Wagner K Mies S Beirle S Slijkhuis D Loyola GOME 2 H20 total column validation report SAF O3M FMI VR H2O 111 April 2011 R10 Delta Validation Report for ERS 2 GOME Data Processor upgrade to version 4 0 ERSE CLVL EOPG TN 04 0001 Iss Rev 1 0 December 2004 R11 Product Specification Document of the GOME Data Processor ER PS DLR GO 0016 Iss Rev 4 B December 2004 R12 GOME 2 Level 1 Product Format Specification EPS MIS SPE 97232 2008 R13 GOME 2 Products Guide EUM OPS EPS MAN 05 0005 Issue 1 0 February 2005 R14 HDF5 File Format Specification http www hdfgroup org HDF5 R15 BUFR Format Specification http www wmo int pages prog www WDM Guides Guide binary 1A html R16 Eumetcast Dissemination Facility http www eumetsat int website home Data DataDelivery EUMETCast index html R17 Eoweb DLR Online User Service http eoweb dlr de 10 DLR Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 0
46. iption JP p Values NumberOfFittingWindows integer Number of fitting windows used in processing 1 M This table describes data sets containing information about the fitting windows odo Allowed Dataset Name Data Type Description Volles FWName string windows Names of 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 MainSpecies string windows Name of the main reference species retrieved in this fitting string window VCDQualityIndicator float windows Percentage of flagged pixels see QualityFlags 0 2 in 6 8 3 for 0 100 this window 30 Product User Manual for GOME Total Columns of Ozone DLR GOME PUM 01 NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 31 of 49 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 _ flight direction ay Lo a a p O ug Is Cap B at ground at TOA Figure 5 Ground Pixel Geometry The term pixels denote the number of ground pixels whereas the term PMDpixels denote the total number of PMD subpixels 31 DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 Product User Manual for GOME Total Columns of Ozone NO2 tropospheri
47. ir de gome2 9 Eenariment ospheric Processors JApplled Remote Sensing GOME ERS 2 GOME 2 MetOp A Product Navigation DLR genera operational Chemistry 03M SAF onez 9 0 2735 zotero S gt 9 05 Now Snow 6 C 5 gt Wed 4 C gt Thu 4 C Figure 3 GOME 2 MetOp web page at DLR 18 Product User Manual for GOME Total Columns of Ozone DLR GOME PUM 01 NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 19 of 49 5 Total Column Trace Gases and 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 DU and molecules cm Total H O column amount kg m and molecules cm Other trace gas column amounts molecules cm Cloud fraction and cloud top albedo optical thickness unitless Height km Pressure hPa Angles are given at satellite and at Top of Atmosphere 0 to 360 degrees TOA 70 km Geographical Coordinates longitude 0 to 360 degrees latitude 90 to 90 degrees Errors relative values 96 5 2 Geographical Coverage and Granularity GOME ERS 2 has a nominal glo
48. ixels DU O3 column FitPar2 TemperatureShift float pixels K Temperature shift FitPar3 Albedol float pixels Internal closure parameter 1 FitPar4 Albedo2 float pixels Internal closure parameter 2 FitPar5 Albedo3 float pixels Internal closure parameter 3 FitPar6 Ring float pixels Fitted ring spectrum FitPar7 Undersampling float pixels Fitted undersampling FitPar8 WavelengthShift float pixels nm Fitted earthshine spectrum shift NumberOflterations float pixels Number of fitting iterations FittingRMS float pixels Final RMS of the fit O3Temperature float pixels K Fitted ozone temperature including T Shift GhostColumn float pixels DU Associated ghost column CovarianceMatrix float pixels 8 8 Covariance and Correlation results matrix see below AveragingKernels float pixels layers Averaging kernels for each atmosphere layer For the fitting parameters the general name scheme is FitParN_ lt name gt where N is the number of the fitting parameter and lt name gt the corresponding name With this approach the desired dataset can be retrieved from the product even if the position in the fitting vector should change in the future The Covariance dataset contains a square matrix with the dimensions of the fitting vector In the lower left triangle the covariance is available the diagonal contains the variance and the upper right triangle contains the correlation cory Cov sqrt covi cov f
49. m value in this dataset present only when applicable ValueRangeMax same as dataset Maximum value in this dataset present only when applicable 27 DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties Page 28 of 49 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 means that the attribute can contain any string within the UMARF size limit Allowed Values Allowed Values Attribute Name Data Type Description Typ p 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 i e integer integer at the beginning of a dump InstrumentID string Instrument which acquired the product GOME GOME InstrumentMode VIEW MODES Specifies how many ground pixels were VIEW MODES VIEW MODES structure observed in the corresp view modes structure structure SensingStartTime CCSDS ASCII UTC date and time at sensing start Date in CCSDS Date in CCSDS
50. main cloud properties of each pixel are stored Dataset Name 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 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 96 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 used for cloud retrieval PMDCloudFraction float PMDpixels Cloud fraction for forward scan PMD subpixels 34 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO
51. mission ERS2 METOPA METOPB METOPC e 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 denotes the product format used HDF5 or BUFR For example the following identifier denotes a GOME ERS 2 off line product GOME O3 NO2 L2 20060723165752 023 ERS2 58855 DLR 05 HDF5 The following example is a valid name for a GOME 2 MetOp off line product GOME O3 NO2 BrO L2 20070302111155 047 METOPA 01900 DLR O1 HDF5 Note The GOME 2 MetOp NRT products disseminated via EUMETCast have a fixed prefix file name S O3M see the following examples S O3M GOME O3 NO2 NO2Tropo SO2 L2 20121205144758 003 METOPA 31808 DLR 03 HDF S O3M GOME O3 NO2 SO2 L2 20121205144758 003 METOPA 31808 DLR O3 BUFR s DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 22 of 49 DLR 5 8 Product Dissemination 5 8 1 GOME ERS 2 GOME ERS 2 products are available at the D PAF FTP server eoa dp eo esa int The products are organized in directories as follows products level 2 HDF5 YYYY MMIDD where YYYY is the year MM the month DD the day For requesting a FTP user account see 5 9 1 5 8 2 GOME 2 MetOp The primary dissemination mean of GOME 2 MetOp NRT products is EumetCast using the BUFR and HDF5 format The NRT products in BUFR format are additionally disseminated
52. net and media The ordering of products can be done via dedicated user services The GOME 2 MetOp level 1 products are delivered in NRT approx 1 45 hours after sensing in so called PDU files product dissemination unit containing 3 minutes of measurements via EUMETCast The ground segment at DLR needs less than 15 minutes for acquiring the input data retrieving the trace gas total columns and disseminating the resulting level 2 products Figure 2 that means the GOME 2 MetOp total column products are available to the users in less than 2 hours after sensing The GOME 2 MetOp operational processing is performed in a high availability virtualized environment on a blade center farm eds Product User Manual for GOME Total Columns of Ozone DLR GOME PUM 01 Geodata Access wmsmcs geoservice dlr de NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 17 of 49 EUMETCast FTP push 5 5 WMO Global S Telecom System 5 73 B EUMETCast Near real time Online Archive FTP E receiving station UPAS atmos eoc dir de z Online Archive FTP atmos eoc dlr de Z L A EUMETCas L1 orbit B ew i nd geoservice dlr de 2 receiving station bundling 5 Assimilation WDC RSAT 3 Offline Long term idolo UPAS archiving Catalogue Order eoweb dir de 5 Quality EUMETSAT H3 assurance Data Center x Figure 2 GOME 2 MetOp processing chain 4 3 Data Management The processing o
53. nith angle at TOA Point F SolarZenithAngleG float pixels degrees Solar zenith angle at TOA Point G LineOfSightZenithAngleE float pixels degrees Line of sight zenith angle at TOA Point E LineOfSightZenithAngleCentre float pixels degrees Line of sight zenith angle at TOA Point F LineOfSightZenithAngleG float pixels degrees Line of sight zenith angle at TOA Point G RelativeAzimuthE float pixels degrees Relative azimuth at TOA Point E RelativeAzimuthCentre float pixels degrees Relative azimuth at TOA Point F RelativeAzimuthG float pixels degrees Relative azimuth at TOA Point G SolarZenithAngleSatE float pixels degrees Solar zenith angle at satellite Point E SolarZenithAngleSatCentre float pixels degrees Solar zenith angle at satellite Point F SolarZenithAngleSatG float pixels degrees Solar zenith angle at satellite Point G LineOfSightZenithAngleSatE float pixels degrees Line of sight zenith angle at satellite Point E LineOfSightZenithAngleSatCentre float pixels degrees Line of sight zenith angle at satellite Point F LineOfSightZenithAngleSatG float pixels degrees Line of sight zenith angle at satellite Point G RelativeAzimuthSatE float pixels degrees Relative azimuth at satellite Point E RelativeAzimuthSatCentre float pixels degrees Relative azimuth at satellite Point F RelativeAzimuthSatG float pixels degrees Relative azimuth at satellite Point G SubSatellitePointLongitude float pix
54. oduct 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 InitializationFile Version string Version of the configuration file used for 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 gases included in the product comma separated string list SubsettingRegion string Description of the sub setting region full means no string subsisting was applied 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 Long of the sub satellite point at start of acquisition 0 360 SubSatellitePointEndLat float Latitude of the sub satellite point at end of acquisition 90 90 SubSatellitePointEndLon float Long of the sub satellite point at end of acquisition 0 360 SatellitePosition POS_VEC Position vectors X Y Z in km Vector in POS_VEC SatelliteVelocity 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 floa
55. omic they can contain variable length data structures When entries for a pixel or pixel window combination cannot be calculated using the normal processing 25 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 26 of 49 DLR procedure fill in values are written to the arrays Also not all datasets defined here have to exists in every product Please note that this description is only valid for the actual version of the product format currently 2 F 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 versions in parallel Each dataset has five associated attributes Title Unit FillValue ValueRangeMin and ValueRangeMax Figure 4 These are used to describe the contents of the array Values in the META DATA group are stored as attributes of the group META DATA GEOLOCATION Attributes present for every dataset Time 012 Title Longitude 012 Unit Latitude o 1 2 N FillValue ValueRangeMin TOTAL_COLUMNSI ValueRangeMax 03 0 i1 2 N 2 UE pem M N nuber of ground pixels BrO 01 2 N M nuber of fitting windows CLOUD_PROPERTIES CloudFraction 01 2 N
56. or j gt i upper right triangle 38 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties DLR Page 39 of 49 DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 6 8 Detailed Flag Description 6 8 1 ViewMode Bit s Value Description 0 7 0 4 0 Nominal 1 Narrow 2 Static Nadir 3 SouthPolar 4 NorthPolar 8 256 DescendingFlag Set when ground pixel is in descending part of orbit 6 8 2 SurfaceConditionFlags Flag Value Description 0 1 Land Sea Set when at least 60 of the ground pixel s area is classified as sea 1 2 Sun glint Set when at least one of the PMD subpixels is affected by sunglint 2 4 Snow Ice These flags give additional information about the surface state during the retrieval 6 8 3 QualityFlags Fla Val Specified Valid Conditions ER Description g 03 NO2 BrO SO2 H20 HCHO OCIO 0 1 Validity of total column retrieval retrieval retrieval retrieval retrieval retrieval retrieval VCD possible possible possible possible possible possible possible If the retrieved total and result column is invalid it is gt 0 replaced with the fill value and this flag is set together with flags 1 and 2 1 2 Total column VCD out 75 700 0 5 10 0 1 5 10 10 0 100 1 0 10 0 3 of range DU mol cm mol cm 1000 DU kg m mol cm 1
57. r for reprocessed total 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 11 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 12 of 49 DLR 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 nm to 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 next 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
58. s R1 R2 R3 R4 R5 P Valks D Loyola N Hao P Hedelt S Slijkhuis M Grossi Algorithm Theoretical Basis Document for GOME 2 Total Column Products of Ozone Tropospheric Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties GDP 4 5 for O3M SAF OTO and NTO DLR GOME 2 ATBD 01 Iss Rev 2 H 2013 R Spurr M van Roozendael D Loyola C Lerot J van Geffen J van Gent C Fayt J C Lambert W Zimmer A Doicu S Otto D Balis M Koukouli C Zehner GDP 5 0 Upgrade of the GOME Data Processor for Improved Total Ozone Columns Algorithm Theoretical Basis Document DLR GOME ATBD GDP5 Iss Rev 1B August 2012 Algorithm Theoretical Basis Document for 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 J C Lambert M Koukouli D Balis J Granville C Lerot and M Van Roozendael GDP 5 0 Upgrade of the GOME Data Processor for Improved Total Ozone Columns Validation Report TN IASB GOME GDP5 VR Iss Rev 1B August 2012 D Balis M Koukouli D Loyola P Valks N Hao GOME 2 O4 total column validation report SAF O3M AUTH VR O3 3 November 2009 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 10 of 49 DLR R6 J C Lambert G Pinardi J Granv
59. sors 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 198 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OCIO and Cloud Properties Page 14 of 49 DLR 2 4 Measurement Scenarios Timelines and Instrument Modes GOME ERS 2 and GOME 2 MetOp follow in general the same operational scenarios see http gome eumetsat int http www eumetsat int 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 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 throug
60. t 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 CCSDS Date NumberOfGroundPixels integer Number of ground pixels in the product int DegradedRecordCount integer Number of records which could not be processed int DegradedRecordPercentage integer Percentage of records which could not be processed 0 10096 MissingDataCount integer Number of missing data records int MissingDataPercentage integer Percentage of missing data records 0 10096 GR DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties Page 30 of 49 DLR The next table contains metadata specific to the total column products Allowed Attribute Name Data Type Descr
61. ted gt 100 unpolluted Cloud fraction CF lt 10 lt 10 Cloud top height cloud top pressure CTH CTP lt 10 lt 10 Cloud albedo cloud optical thickness CTA COT lt 10 lt 10 NRT and OL products have the same accuracy and precision 20 Product User Manual for GOME Total Columns of Ozone DLR GOME PUM 01 NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 21 of 49 5 6 Product Formats The format of the product file is either HDF5 or BUFR A detailed description of the HDFS5 product format is given in section 6 on page 25 and for the BUFR product in section 7 on page 42 5 7 File Name The file name of a product already contains important information about the dataset including trace gases and sensing time It is built according to the following structure SENSOR_GAS_LV_YYYYMMDDhhmmss_ddd_MISSION_ PRO_RV TYPE e SENSOR denotes the instrument i e GOME e GAS is a separated list of trace gases included in the product The acronyms from the above table are used e g O3 NO2 BrO is a products containing these three trace gases e LV is the product level i e L2 e YYYYMMDD are the year month and day of the first processed ground pixel e hhmmss are the hours minutes and seconds of the UTC time stamp of the first processed ground pixel e ddd is the three digit duration of the product in minutes e MISSION denotes the
62. ternal data dependency e VCD and VCDCorrected contain fill values e TOTAL COLUMNS SO2 contain fill values 40 Product User Manual for GOME Total Columns of Ozone DLR GOME PUM 01 NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 41 of 49 6 8 6 H2O_Flags Flag Value Description 0 1 Measurement in cloudy conditions e reduced quality of H2O total column e TOTAL COLUMNS H2O contain fill values 1 2 Measurement in cloudy and or elevation conditions small O2 column e reduced quality of H2O total column e TOTAL COLUMNS H20O contain fill values 6 8 7 HCHO Flags Flag Value Description 0 1 Measurement with high solar zenith angle SZA gt 70 deg e reduced quality of HCHO total column e TOTAL COLUMNS HCHO contain fill values 1 2 Cloudy conditions e reduced quality of HCHO total column e TOTAL COLUMNS HCHO contain fill values Note CloudFraction gt 40 2 4 HCHO column data not available e DETAILED RESULTS VCD contains fill values e TOTAL COLUMNS HCHO contain fill values 3 8 HCHO column data not available due to unfulfilled external data dependency e DETAILED RESULTS VCD contain fill values e TOTAL COLUMNS HCHO contain fill values 41 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Iss Rev 2 F Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO 28 June 2013 OC
63. the end of each optical path 13 to 16 collect information about the signal in each channel Figure 1 GOME optical layout courtesy of ESA ESTEC P Product User Manual for GOME Total Columns of Ozone DLR GOME PUM 01 NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO Iss Rev 2 F and Cloud Properties 28 June 2013 DLR Page 13 of 49 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 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 2 data archive a D
64. us Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties DLR GOME PUM 01 Iss Rev 2 F 28 June 2013 DLR Page 3 of 49 Document Change Log Issue Rev Date Seeng 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 2006 4 5 Content of chapters added 1 C 10 November 2006 all First official version of this document 1 D 6 March 2007 5 7 Fix file name convention 6 2 6 5 Added VCDQualityIndicator QualityFlags CloudMode CloudType AMF Total 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 2008 all Revised following ORR B 28 January 2009 6 Finalized HDF5 product format Moved trace gas specific datasets into groups inside DETAILED RESULTS Moved cloud properties into own group 2 B 16 November 2009 6 Update H2O and HCHO format new sections 6 6 4 6 6 5 6 7 4 6 7 5 Minor corrections SurfaceAlbedoRW SurfaceAlbedo Total Columns and BrO cleanup 18 December 2009 6 PixelFlag under Geolocation section is renamed to SurfaceConditionFlag SurfaceConditionFlag definition added H2OFlag definition changed

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