EUMETSAT GPRC Report. Tim Hewison, Marianne Koenig, Sebastien Wagner, Rob Roebeling, Peter Miu, Jörg Schulz, Harald Rothfuss EUMETSAT

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1 EUMETSAT GPRC Report Tim Hewison, Marianne Koenig, Sebastien Wagner, Rob Roebeling, Peter Miu, Jörg Schulz, Harald Rothfuss EUMETSAT Slide: 1

2 Overview Satellite Status GEO LEO IR Products for current Meteosats using IASI GEO Solar band Channels for current Meteosats Re calibration of Meteosat archive data Other Slide: 2

3 EUMETSAT space segment current planning YEAR METEOSAT FIRST GENERATION METEOSAT 6 METEOSAT 7 METEOSAT SECOND GENERATION METEOSAT 8 METEOSAT 9 METEOSAT 10 METEOSAT 11 METEOSAT THIRD GENERATION MTG l 1 MTG S 1 MTG l 2 MTG l 3 MTG S 2 MTG l 4 EUMETSAT POLAR SYSTEM (EPS) METOP A METOP B METOP C EPS SECOND GENERATION OCEAN SURFACE TOPOGRAPHY MISSION JASON 2 JASON 3 JASON CONTINUITY OF SERVICES (CS) THIRD PARTY PROGRAMMES GMES SENTINEL 3 GMES SENTINEL 4 ON MTG GMES SENTINEL 5 ON EPS SECOND GENERATION Slide:

4 Operations Satellites Status Operational status of the geostationary and LEO systems is stable: Meteosat 7 at 57.5 E is servicing the IODC (Indian Ocean Data Coverage) Mission Meteosat 8 (MSG 1) is located to 9.5 East and performs the operational rapid scanning service. MSG 3 and Meteosat 9 (MSG 2) provides primary service at 0. Metop A Low Earth Polar Orbit System performance is stable and all instruments are in an operational state. Jason 2 Low Earth Inclined Orbit System service for Near Real Time products has confirmed to be stable. Slide: 4

5 Summary of planned Launches MSG Metop B 2013: GMES Sentinel 3 A (ESA) 2014: Jason : MSG : Metop C 2017: GMES Sentinel 3B (ESA) 2018: 1 st MTG I 2017: 1 st Jason CS (after Jason 3) 2019: 1 st MTG S (with GMES Sentinel 4 Instrument) 2019: 1 st EPS SG Satellite ready for launch (VII, IRS, MWS, S5, etc) 2021: 2 nd EPS SG Satellite mission ready for launch (ASCAT, MWI) 2022: 2 nd MTG I Slide: 5

6 Operational Support for Forthcoming Launches Support commissioning of Meteosat 10 (MSG3) by running prototype inter calibration wrt Metop A/IASI Validate potential variations to official SRF Perform SEVIRI Solar Channel Calibration & analyse Monitor Metop A/IASI and Metop B/IASI by double differencing against Meteosat/SEVIRI also applicable to Metop A/HIRS and Metop B/HIRS Starting planning inter calibration activities for Sentinel 3 SLSTR Sea and Land Surface Temperature Radiometer OLCI Ocean and Land Colour Instrument Slide: 6

7 Sentinel 3: Continuity of ENVISAT Ocean Observation Launch Expected end 2013 Operated by EUMETSAT for GMES (EU programme) EUMETSAT plan inter comparison activities: cal/val, performance monitoring, inter calibration following GSICS principles and methodologies SLSTR IR: IR comparison with IASI Currently studying SNO v Statistical method NWP also possible Sea and Land Surface Temperature Radiometer GPS Microwave Radiometer Ocean and Land Colour Instrument X band Antenna OCLI + SLSTR Solar: Compare with LEO instruments (MODIS, VIIRS, ) Combination of invariant targets and Direct ray matching methods Also compare with GEOs potential reference instruments! Laser retroreflector S band Antenna Slide courtesy of Craig Donlon (ESA) DORIS Antenna SAR Radar Altimeter

8 Overview Satellite Status GEO LEO IR Products for current Meteosats using IASI GEO Solar band Channels for current Meteosats Re calibration of Meteosat archive data Other Slide: 8

9 GSICS Activities at EUMETSAT GEO LEO IR Products for current Meteosats using IASI: GSICS Corrections revised netcdf convention GSICS Bias Monitoring Developing new web based Tool Uncertainty Analysis manuscript submitted for special issue Ice Contamination manuscript submitted for special issue GEO Solar band Channels for current Meteosats: Review of SEVIRI Solar Channel Calibration System Implementation of GSICS DCC inter calibration v MODIS Development of Lunar Calibration method Evaluating methods to re calibrate Meteosat archive data: Using multiple NOAA/Metop/HIRS as reference Instrument Event Logs covered under agenda item 8.2

10 IR Products for current Meteosats using IASI GSICS Corrections Near Real Time and Re Analysis Corrections updated daily since 2008 Published in netcdf format on GSICS Data and Products Server Now in Demonstration mode, based on prototype code Pre Operational candidate, based on Operational code but unresolved differences GSICS Bias Monitoring Prototype static plots published on web pages since 2008 Developed interactive tool to generate plots directly from netcdf files Uncertainty Analysis Published for each Correction Ice Contamination Model Developed to explain trend in bias of IR13.4 channel

11 GEO LEO IR Uncertainty Evaluation Extended Error Budget for Meteosat IASI GSICS Corrections Following QA4EO / GUM Processes at each step of ATBD introducing: Random Uncertainties Dominated by spatial/temporal variability over 3km/300s Validated using time series statistics Systematic Uncertainties Dominated by spatial/temporal mismatches Total uncertainties depend on radiance Mostly dominated by random processes Errors much lower in WV channels See also poster by Tim Hewison

12 Ice Contamination Model Inter calibration results show Trend in 13.4μm channel bias Currently 0.4K/yr Step change of +0.7K at last decontamination With gain change +35% In 12.0μm channel 1μm thick layer of ice Reduces gain Modifies SRF Introduces bias Example time series plot showing relative bias of IR channels of Meteosat 9/SEVIRI (MSG2) wrt Metop A/IASI, expressed as brightness temperature difference for standard radiance scenes. A spacecraft decontamination in Dec 2008 reduced the bias of the 13.4 μm channel, which subsequently continued to deteriorate. Transmittance spectra of ice layers of different thicknesses (black): 0.1 to 1.0 µm layers (thickest layers have lowest transmittance) and Spectral Response Functions (SRFs) of Meteosat 8 infrared channels (red). Brightness Temperature Bias modeled by modifying SRF by the ice transmittance. Solid lines show the predicted differences, based on calculation clear skies (red line with crosses) and high cloud (blue line with diamonds).

13 Example of New Bias Monitoring Tool Reads data directly in netcdf format from GSICS Servers EUMETSAT Development Prototype:

14 Overview Satellite Status GEO LEO IR Products for current Meteosats using IASI GEO Solar band Channels for current Meteosats Re calibration of Meteosat archive data Other Slide: 14

15 Meteosat Solar Band Calibration Activities Vicarious calibration using desert targets + sea targets (current official calibration) SEVIRI Solar Channel Calibration System (presented in Daejeon, 2011) Lunar Calibration Collaboration with USGS METEOSAT imagers MVIRI (Meteosat First Generation) SEVIRI (Meteosat Second Generation) FCI (Meteosat Third Generation) Preparation to MSG3 launch + reprocessing activities Inter calibration with MODIS using Deep Convective Clouds Implementation of the GSICS ATBD (Doelling, 2011)

16 SEVIRI Solar Channel Calibration System Impact of uncertainties (in radiance) Uncertainty analysis on the Radiative Transfer Model (defined as our calibration reference): Atmospheric gaseous composition Geometry (geo location) Aerosol load Surface properties Biggest source of uncertainties: surface properties + aerosols (no surprise but quantified). (Presented at EUMETSAT Conference, Sept 2011) Future work: Assessment of the current system uncertainties to be continued Re assessment of the desert target stability + definition of new targets with associated BRF Improvement of the RTM Re evaluation of the reference against reference instruments Implementation of additional methods such as DCC or homogeneous water clouds (in particular for MTG FCI non window channels) Effect on the slope (in %) Effect on the slope (in %) VIS06 VIS08 NIR16 = 30% = 20% = 100% (Ref = 0.1) = 2% = 1% Impact of uncertainties (in reflectance) VIS06 VIS08 NIR16 = 30% = 20% = 100% (Ref = 0.1) = 2% = 1%

17 Meteosat Solar Band Calibration using Lunar Observations Meteosat SEVIRI: Lunar observations available in the 4 image corners More than 100 potential observations / year Achievements: 1.Development of an automatic extraction tool for lunar observations for LRES channels 2.Creation of a database of lunar observations with MSG1 and MSG2 3.Collaboration with USGS proof of concept: interband calibration using the ROLO model as a reference works! (~1% relative error) Future work: SEVIRI Level 1.0 image (forward and backward scan) Consolidation of the extraction tool for RSS data and HRVIS Consolidation of the existing database of lunar observations (MSG1 / MSG2) Assessment of lunar calibration capacities with MFG MVIRI sensor Operational extraction of the SEVIRI lunar observations Development of a tailored version of the ROLO model in order to perform operationally lunar calibration (MSG / MTG)

18 Preliminary results for SEVIRI onboard Meteosat 8 and 9 SEVIRI Meteosat 8 SEVIRI Meteosat 9 Note: End at the end of 2005 after the start of Rapid Scan Service Results to be used only for inter band calibration and drift monitoring Lunar calibration method and instrument are stable. SD <1% consistent with expected performance of ROLO Þ BUT is it affected by seasonality? Relative difference between channels = consistent with current findings in terms of absolute calibration. Slide: 18 Courtesy T. Stone, USGS To be presented in IGARSS Munich 2012

19 Inter calibration against MODIS/Aqua using DCCs Implementation still on going Process for checking in MODIS + SEVIRI images in place Thresholding to extract DCCs in place for MODIS + SEVIRI Ray matching to establish bias between MODIS and SEVIRI BT missing (BUT numbers provided by D. Doelling) Spectral transformation of the data missing (BUT numbers for the spectral adjustment provided by D. Doelling) Angular transformation of the data ( use of an Angular Distribution Model) missing PDF transformation of data in place Gain derivation on a monthly basis in place (in radiance, using modal approach) Uncertainty analysis to associate an uncertainty estimate to the derived gain missing Current difficulties: data storage for MODIS + GEO data no monitoring system in place yet Test on the view zenith angle MODIS (scan N and N+1) MODIS (scan N+1) SEVIRI SEVIRI 12:57 MODIS 13:00 FINAL DCCs for both MODIS Aqua and SEVIRI (Met 9)

20 Overview Satellite Status GEO LEO IR Products for current Meteosats using IASI GEO Solar band Channels for current Meteosats Re calibration of Meteosat archive data Other Slide: 20

21 HIRS Data Objectives Prerequisites and Benefits Objective: To recalibrate time series Meteosat First Generation and Meteosat Second Generation infrared radiances from 1982 till date using a superior instrument as reference. Prerequisites: Inter calibration back to 1982 Target accuracy over the time series better than 1 K Inter calibration with uncertainty estimate Method Select reference instrument Assess the uncertainties through systematic review of spectral conversion functions Define the inter calibration approach Reprocess and validate the Data processing and verification Slide: 21

22 METEOSAT Archive evaluation using radiosondes METEOSAT2 MET4 MET3 MET3 METEOSAT4 METEOSAT5 MET6 METEOSAT7 Upgrade of calibration technique (Schmetz, 1989) Upgrade of calibration technique (van de Berg, et al., 95) ISCCP DX Normalized Instead of nominal Comparisons between the METEOSAT BTs and the simulated BTs from radoisoundings: (+) represent the raw data, ( ) represent the homogeneised data. The histogram shows the nb of soundings used for comparison. Can we do better than that and extend to SEVIRI? Courtesy of Helene Brogniez and Rémy Roca, LMD

23 Traditional inter calibration approach Slide: 23

24 Proposed GSICS inter calibration approach Delta Correction to transfer from one reference to another Defined as differences between inter calibration functions Defined in channel space of monitored instrument No need for direct comparisons of references Delta Slide: 24

25 Proposed GSICS inter calibration approach Delta time steps inserted for illustration only In practice, deltas defined from simultaneous doubledifferences Delta Slide: 25

26 Overview Satellite Status GEO LEO IR Products for current Meteosats using IASI GEO Solar band Channels for current Meteosats Re calibration of Meteosat archive data Other Slide: 26

27 Update on Actions GRWG06_17: Find out time overlaps between geostationary satellites (commissioning and operational periods), find out about the availability of such data and publish this information on the GSICIS Wiki EUMETSAT have generated an Excel file, presenting on a daily basis the availability of the Meteosat satellite data in COM or OPE mode from the Data Centre. It includes a rudimentary chart, which we plan to improve in the future,e.g. provide on web site, add zooming capability, select / deselect Slide: 27