Report from CMA GPRC 20th GSICS Executive Panel, Sochi, Russian Federation, 16-17 May 2019

1. Report from CMA GPRC20th GSICS Executive Panel, Sochi, Russian Federation, 16-17 May 2019 Peng Zhang (NSMC/CMA) GSICS-EP-20, Sochi, Russian Federation, 16-17 May 2019

2. Overall agency update • Overall satellite planning • FY-2H (Belt and Road satellite) was launched in June 5, 2018 and located at 79E. The commissioning test of FY-3D was finished in August, 2018. FY-3D and FY-2H were incorporated into operation in the end of 2018. • FY-4B will be lauched at the end of this year or the beginning of next year. FY-3E early morning satellite will be launched at the second half of next year. • Major satellite events: Third batch programme of FY-3 series including four satellites FY-3E, FY-3F,FY-3G,FY-3H were approved by Chinese government and will be launched in the following five years. • Other major events affecting the agency or its participation in GSICS • The retrospective calibration for FY sensors’ FCDR was found and fully implemented since the second half of 2018. Some interim results have been achieved. • FY-3 MW group has made progresses on SNO inter-calibration, O-B, and its contributions to calibration process correction. • CMA initiated a long term ground-based measurements to improve the lunar irradiance model. The system can be remotely controlled and maintained at Lijiang, Yunnan Province. GSICS-EP-20, Sochi, Russian Federation, 16-17 May 2019

3. Participation in EP, GDWG, GRWG(for GSICS Members) • Points of contacts/meeting participants: • EP: Peng Zhang • GDWG: Zhe XU • GRWG: Xiuqing Hu • Main contribution to GDWG actions • A.GDWG.2018.5d.1:CMA and EUMETSAT to work together to synchronize GSICS products across the servers. • A.GDWG.2018.5d.2:CMA to check if their NetCDF format checking tool can be shared in GSICS. • Main contribution to GRWG actions • A.GIR.2018.4f.1:CMA to apply Likun Wang’s collocation method to LEO-LEO cases. • A.GIR.2018.4c1:JMA/CMA to work together on making GEO-GEO inter-comparison using IASI • A.GIR.2018.4d.1:CMA to compare with the JMA gap filling methods. To report at the next web meeting in 2-3 months. • Comments, feedback • Building the public platform for predicting SNO cross-points or PICS targets. The public platform will not only be available for GSICS member but also for public research user. • CMA could provide prediction tool or platform. • Some demo, including the PICS/SNO Prediction Timetable, L1 filename and PICS extraction data, are available on CMA GSICS THREDDS sever. GSICS-EP-20, Sochi, Russian Federation, 16-17 May 2019

4. Current and prospective GSICS Products • Issues, general comments (e.g. on product types, or acceptance procedure) GSICS-EP-20, Sochi, Russian Federation, 16-17 May 2019

5. Highlights of interest to the EP • Field campaigns for FY-3D Vicarious calibration and validation were conducted at Simao rainforest in March 2018, Dunhuang desert in April 2018, and Qinghu Lake in August 2018. MERSI-II Calibration trend monitoring using PICS sites and ground-based automatic measurements at Dunhuang site and its Integrated calibration system which combines earth targets, moon, DCC and RT simulation • All 10 instruments onboard FY-3D have finished the three-round tests for evaluating the key performances which all meet with specification. Operational Instrument Performance Monitoring for long term based on OBC complete telemetry parameters. GSICS SNO or SNOx monitoring using reference instruments (IASI, CrIS, MODIS,VIIRS). • FY-3D’s 8 instrument payloads: MERSI-II, HIRAS, GNOS, MWTS, MWHS, MWRI, SEM, and IPM have begun operation since Jan 1, 2019 with L1 data dissemination and L2 generation test. GSICS-EP-20, Sochi, Russian Federation, 16-17 May 2019

6. FY-4A: Launched on 11 Dec, 2016

7. FY-4 GSICS IR Inter-calibration • AGRI IR Biases are less than 0.5K for B9/11~14, and about 0.8K for B10； • The stability of B11 and B14 is slight worse than other bands. B9：~0.3K B10：~0.8K B11：~0.5K B12：~-0.2K B13：~-0.2K B14：~-0.4K

8. Latest update of FY4/GIIRS VS IASI Examples of paired spectra between GIIRS and IASI at UTC 0230, 30 January, 2018 (Notes: red line for IASI, blue line for GIIRS) • For a period between August 2017 and March 2018, the averaged absolute monthly biases of GIIRS are assessed to be 0.25K and 0.42K for the two uncontaminated spectral coverages (i.e. 760-1050 cm-1 and 1800-2188 cm-1) respectively, while the annual variation feature of monthly biases appears clearly.

9. FY4/GIIRS VS CrIS&HIRAS wthin CMA GEO-LEO hyperspetral intercomparison Comparison Results between hyperspectral sounders on GEO and LEO GIIRS and HIRAS GIIRS and CrIS GIIRS Bias -0.2K Wrt HIRAS Period: 20190209-20190214 Matched Number: 158 Period: 20180201-20180205 Matched Number: 240 We can also check the HIRAS with CrIS using double difference

10. FY-3D: Launched on 15 Nov, 2017 • Performance are improved significantly for the key characteristics, such as S/N, calibration accuracy, etc.

11. Degradation Evaluation of FY-3A MERSI MERSI-II calibration monitoring Combined Degradation Monitoring Libya DCC Moon

12. Dunhuang VC Integrated VC RSBs Validation using Dunhuang Prelaunch calibration On-orbit validation based on vicarious calibration (VC) Prelaunch laboratory calibration perform well on-orbit, and the biases of most bands are within 5%. The two independent validation results show good consistency. Dunhuang VC Integrated VC Validation results comparison between integrated vicarious calibration (without insitu measurement) and Dunhuang site insitu calibration（2018.05）

13. Degradation Evaluation of FY-3A MERSI MERSI-II monitoring using MODIS RSBs Calibration Bias Monitoring w.r.t. AQUA/MODIS CH1~4 • The data stability of MERSI II is greatly improved, no obviously degradation was found since launched； • The relative differences between MERSI II and MODIS can be kept within 2%(ref=25%) based on the new calibration coefficients。 Calibration Coeff. Update Calibration Coeff. Update

14. HIRAS performance and validation MW @ 1.25cm-1 Res LW @ 0.625cm-1 Res NEdT SW @ 2.5cm-1 Res • Noise performance: derived from DS and ICT measurements • NEdTs derived from DS and ICT are consistent. • NEdTs in forward and reverse sweep direction are consistent. • Meet requirements.

15. After fine optic alignment，noise dominated by random noise Before fine alignment After fine alignment April 20, 2018

16. Spectral bias vs LBLRTM simulation Spectral accuracy within 2ppm, But we also find the small shift on orbit for long term.

17. Calibration bias with respect to IASI • Data:2018.04.22-2018.05.2617 days • LWbt bias better than 0.5K，MW bt bias less than 0.7K； • LWbias std less than 0.5K， MW bias std in 0.5~1K， SWwindow and weak absorption region meet 0.5K ；

18. MW sensors performance and GSICS validation MWRI 1, Improvement on the A/D Bias, using O-B result to decrease the A/D Bias to less than 0.5 K in average. 2, Improvement on the cold sky mirror noise filter, especially on the television transmission satellite of EU and US, 10G and 19G. 3, Inter calibration with GMI, 1-2K bias in ocean and 2-4K in land for most channels, std for all channel are ~1K or less. Bias with GMI

19. MWTS and MWHS wrt NPP/ATMS MWTS MWTS The FY3D-MWTS channel bias is better than 0.6 K except channel 5 , and the middle and upper layers have higher accuracy; Bias std has higher accuracy in the middle atmosphere and better than 0.5 K. MWHS Bias Std for five humidity sounding channels are less than specification and the performance of MWHS II onboard FY3D (green bar) and FY3C (blue bar) is almost similar. MWHS

20. Projects on Space-based Radiometric Benchmark • Founded by • National High Technology Research & Development Program of China (863 program) before 2018 • National Key R&D Program of China after 2018 • Goal • Chinese SI-traceable reference satellite • Retrospective recalibration of historical Chinese EO satellite data

21. Phase B Phase C Phase A • Climate Change Detection, • Calibration Reference Satellite Short-term goal (2014-2018) Medium-term goal (2018-2022) Long-term goal (2022-2025) Since 2012 IR calibrator Blackbody and emissivity measurement on-board Engineering Model for reference instrument Flight Model for reference satellite • Solar total irradiance 0.01% • Solar spectral irradiance 0.1% • Earth reflected solar radiance 0.3% • Earth outgoing longwave radiance 0.1K • Long-term Chinese EOS data EOS SRB calibrator Coherent photon Tech for optical path reuse Instrument & Satellite Solar Spectrum traceable Cryogenic radiometer Space-based CDR Satellite Data Reprocessing Lunar-based calibration for SRB Radiometric benchmark & Traceablility chains Benchmark (Lunar, DCC, PICS) & Traceability chains

22. Phase A （20 million RMB） • National High Technology Research & Development Program of China (863 program) IR calibrator Blackbody and emissivity measurement on-board Shanghai Institute of Technical Physics (SITP), CAS SRB calibrator Coherent photon Tech for optical path reuse Anhui Institute of Optics and Fine Mechanics (AIOFM), CAS Solar Spectrum traceable Cryogenic radiometer Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), CAS Lunar-based calibration for SRB National Satellite Meteorological Center (NSMC), CMA

23. Phase B （300 million RMB） • National Key R&D Program of China • Chinese FY Satellite Program • Chinese HY Satellite Program • Chinese ZY Satellite Program Engineering Model for reference instrument Shanghai Institute of Technical Physics (SITP), CAS Anhui Institute of Optics and Fine Mechanics (AIOFM), CAS Satellite Data Reprocessing National Satellite Meteorological Center (NSMC), CMA Benchmark (Lunar, DCC, PICS) & Traceability chains Academy of OPTO-Electronics (AOE), CAS

24. Seminar on Benchmark Sensor – Beijing 2018

25. RetrospectIve Calibration of Historical Chinese Fengyun Satellite Program (RICH-FY) • Project RICH-FY has been founded by National Key R&D Program of China since 2018. • Goals :Reprocessing/Recalibration and FCDR generation for VNIR, IR, MV observations of FENGYUN Meteorological satellite archive data for climate and environment change research Sensor: FY-1A/B/C/D FY-3A/B/C VIRR FY-3A/B/C MERSI/IRAS/MWTS/MWHS/MWRI FY-2A/B/C/D/E/G VISSR • Activities: • Data quality assessment and diagnose for Long-term historical data • High accurate re-navigation and Solution to missing of satellite attitude/orbit/GPS information at early phase • Reconstruction of defective/missing data in pixels or lines (AI) • Reference transfer for Inter-satellites consistent calibration • Long-term Recalibration and FCDR generation (consistent L1) • Typical Thematic CDR generation including SST, OLR, LST, NDVI • Rapid processing system establishment and distribution of satellite big data (Cloud/Big data tech) GSICS-EP-20, Sochi, Russian Federation, 16-17 May 2019

26. Consistent Calibration of VIRR Reflective Solar Channels Onboard FY-3A, FY-3B, and FY-3C Using a Multisite Calibration Method Time series of the nadir (viewing angle within 10°) reflectance data in RSBs over Libya 4 from January 2009 to December 2017. (a,b) Operational calibration results; (c,d) recalibrated results using the MST calibration method Trends in the VIRR normalized calibration slopes for (a) FY-3A, (b) FY-3B, and (c) FY-3C. Ling Wang, Xiuqing Hu , Lin Chen, et al. . Remote Sensing, 2018, 10(9), 1336.

27. After recalibration Radiometric Evaluation and re-calibration of FY2 -VIS Band Operational calibration Lin Chen, et al.2016

28. Dunhuang base for Automatic vicarious calibration was established in 2015

29. Feedback on GSICS deliverables(one slide) • Satellite data users (internal) • Application: CMA GSICS platform become the essential and necessary tools for the satellite commissioning test and instrument monitoring • Application: Intercomparison between MERSI-II imager and HIRAS hyperspecral instrument at the same satellite FY-3D provide excellent opportunity of mutual radiometric evaluation and stability monitoring • As a satellite operator • Building the public platform for predicting SNO cross-pionts or PICS targets is necessary. The public platform will be avaliable not only for GSICS members but also for public research user. • CMA could provide prediction tool or help to build the platform. • Some demos, including the PICS/SNO Prediction Timetable, L1 filename and PICS extraction data, will be available on CMA GSICS THREDDS sever. GSICS-EP-20, Sochi, Russian Federation, 16-17 May 2019

30. CMA support initiation of Recalibration/Repeocssing workshop in the GSICS community Issues or suggestions for discussion by the GSICS EP • In GSICS 2019 annul meeting: Several projects and agencies involved in the re-calibration/reprocessing task • EUMETSAT, UK, JMA,CMA, NOAA, ESA, ECWMF • SCOPE-CM, ISCCP, FIDUCEO, CM SAF, CCI, Chinese Recalibration Project • Lots of instruments involved in re-calibration/reprocessing • GEO-Ring, HIRS, VIIRS, FY-1/3 VIRR/MERSI, FY-2/VISSR, FY-3/MWRI • One important item of GSICS Scopes: • Provide ability to re-calibrate archived satellite data with consensus GSICS approach, leading to stable fundamental climate data records (FCDR) • CMA suggest to take the first Recalibration/Repeocssing workshop in 2020 hosted by one GSICS member GSICS-EP-20, Sochi, Russian Federation, 16-17 May 2019

31. 谢 谢！