Benefits from GSICS algorithms for FY-2/3 calibration Presented by Lei Yang Contributor: Xiuqing Hu, Na Xu, Hanlie Xu, Lin Chen, Ronghua Wu, Ling Wang, Yuan Li, Ling Sun, Chengli Qi, Peng Zhang National Satellite Meteorological Center(NSMC), CMA Sep 22, 2015 GSICS Users Workshop 2015, Toulouse, France

Outline FY-2 GEO-LEO and FY-3C LEO-LEO IR toward demonstration products FY-2/FY-3 VIS/NIR inter-calibration FY2 and FY-3 Lunar calibration FY-3C/MERSI Nonlinear correction from inter-calibration Other progresses in CMA GPRC Data group and Data sharing sever IR Solar contamination of FY-3 instruments Spectral response error and retrieval VIS/NIR PICS monitoring Instrument Performance monitoring IPM

Collocation & Correction Products** Current Status of CMA GSICS Products Mon Ref Graphic Products## Collocation & Correction Products** FY2D&E&F/ VISSR Metop-A/IASI (Op.) AQUA/AIRS (Op.) NPP/CrIS (Developing) Ocean buoy RTM (Plan) Daily Regression (RAD~RAD and TBB~TBB) Monthly Scatter of TBB Bias Time Sequence of TBB Bias Collocation Samples Intercalibration Coefficients NRTC and RAC in txt (Plan to generate the GSICS standard format) FY3A&B&C/MERSI &VIRR NPP/CrIS (Demo) Monthly Regression (RAD~RAD and TBB~TBB) AQUA&TERRA MODIS (Demo) NPP/VIIRS (Demo) GOME (Developing) Monthly Regression (REF~REF) Monthly Scatter of REF Bias Time Sequence of REF Bias Projected Image NRTC and RAC Stable Targets Tracking (Developing) Time Sequence of Response Degradation Rates TEB RSB ## : see http://gsics.nsmc.cma.gov.cn/queryIndexPage.action ** : Only Internal Shared currently.

FY-2 GEO-LEO IR calibration GSICS monitoring Latest Results 徐娜 GSICS CIBLE 2013 2014 @290 K for IR1 and IR2 @250 K for IR3 FY-2D窗区通道亮温偏高，IR1偏高约1~2K，IR2偏高约2~3K，水汽通道亮温偏高0.5~1K； FY-2E窗区通道亮温表现为系统性偏差，IR1约偏低0.5~1K，IR2约偏高1~2K，水汽通道亮温偏低2~3K； FY-2F定标偏差表现出显著的季节变化特征，冬季偏差大夏季偏差小，窗区通道亮温偏高，IR1约偏高1~2K，IR2约偏高2~3K，水汽通道亮温偏低1~2K。 IR1与IR2之间存在约-1.5K（DTBB_IR1-DTBB_IR2）的系统性偏差 MTSAT平均亮温偏差IR1~2约0.1K，IR3约-0.15K. FY-2D&E&F热红外通道亮温偏差时序图

Bias Correction Coefficient Generation Linear regression is used as the basis of the systematic comparison of collocated radiances (counts or brightness temperature) from two instruments. ILEO ar br ISTD ΔISTD IGEO Correction coeff Bias Filting Matching distribution

FY-3C LEO-LEO IR calibration GSICS monitoring FY-3C/VIRR IR GSICS Red: FY3C/VIRR-CrIS Blue:FY3C/VIRR-IASI

FY-3C/IRAS Inter-Cal with IASI FY-3C/IRAS Cal bias rwt IASI in first year: Ch2~Ch15<1.0K CH3<-2.0K CH16~Ch18>2.0K CH1, CH14~CH20 have large seasonal dependence IRAS-CrIS matching processing is also in operation and bias analysis will be done

CMA GSICS Towards demo products Theoretical Basis for FY-2-AIRS/IASI Inter-Calibration Algorithm for GSICS Na Xu (CMA) Version : 2015-01-30 Theoretical Basis for the FY-3 MERSI/VIRR/IRAS- IASI/CrIS Inter-Calibration Algorithm for GSICS  Hanlie Xu (CMA), Chengli Qi (CMA) Version: 2015-02-09 Submission for review will be done after GSICS 2015 annual meeting

DCC Consistency between FY2D~2F and MODIS FY2D has the greatest calibration bias, and the degradation is about 8%； Yearly degradations of FY2D and FY2E are similar, and are about 1%； FY2F is much stable than FY-2D/E Bias Degradation Rate

FY2D compared with MODIS FY2D Nadir： 86.5°E ROI ：10°S-10°N， 75°E-95°E FY2D compared with MODIS Mean reflectance of ROI FY2E-Operation： 19.06 FY2E-Correct ： 28.13 MODIS： 29.29 Before After

FY-3C/MERSI Calibration monitoring by DCC DCC Monitoring Assessment with MODIS

FY-2E Lunar calibration Phase Angle=40.5 Num of Lunar Pixels=26295 Abnormal Extremly low Phase Angle=42.0 Num of Lunar Pixels=39018 Linear fitting regression(f) is used here to get the instrument degradation: Rate is the annual degradation rate. STD means the standard diviation of each spot minus fi

FY-3C/MERSI degradation using moon observation Using Inter-band ratio Based Ch03 Annual degradation% 1 2 3 4 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 2.58 -0.51 -0.1 4.72 2.09 14.55 8.42 3.58 1.63 0.9 0.38 0.63 0.46 3.49 -1.4 1.15 0.96

CMA Lunar calibration project was funded CMA Team acquired a project funding from Chinese MOST (Ministry of Science and Technlogy) "Solar bands calibration technique based on Lunar radiance source” (2015~2017) . The main research points of this project include: moon prediction and geolocation, lunar radiance/irradiance model development, ground-based measurement and model validation and calibration algrithm development for satellite sensor.  Collaboration partners: National = Astronomical Observatories, Chinese Academy of Sciences(CAS)  Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), CAS Nanjing University Jilin University Prediction model for lunar position and geolocation of Lunar imager. A model of Full-disk Lunar Radiance Model A albedo model of Uniform Target on lunar surface Validation of Lunar model by ground-based measure Lunar Calibration algorithm development used for FY-3 Lunar Calibration algorithm development used for FY-2/4 Monitoring Degradation of sensors by lunar observation Inter-calibration based on lunar observation

Lunar Ground-based measurement Image size 160*160pixels Spatial resolution 38km×20km@moon Spectral range 400-1000 nm Spectral resolution 2~10 nm SNR  600 Tracking Camera 500*500 VIS Lunar irradiance measurement from these two kinds of instruments for lunar model establishment and validation. Field Campaigns were conducted for the instruments checking two times in June and August, 2015 Spectrometer Imaging Image size No imaging Spectral range 400-2500 nm Spectral resolution 2~8 nm SNR  500 Tracking Camera ?? Hyperspectral Moon-photometer

Non-linear correction Using GSICS FY-3C/MERSI Integrated/Synergic Calibration—Combined Methods Red line: New calibration Blue line: Prelaunch SRBC Yellow *: SNO sample based on GOME-2 Purple *: Statistical measurements over Deep Convective Clouds (DCC) (Chen et al., Remote Sens. 2013) Temporal variation of daily intercalibration slope segmentation fitting is preferable. The new calibrations : consistent with SNO samples based on MODIS and GOME-2. lower over high reflectance comparing with linear results, and nearly go through DCC samples, and the reflectance difference less than 1%. Segmentation fitting is preferable for getting more appropriate calibration over the whole dynamic .

FY-3C/MERSI Non-linear fitting involved GOME-2 and bright stable targets Band 8-9 Linear fitting: DN=4096，Ref=91%，is not matching in DCC saturation Non-linear fitting：has largely improvement

FY-3C Instrument monitoring is in operation Instrument Monitor of FY-3C will be added to the static pages firstly

CMA GSICS Server Updated CMA New Server in operation, hardware performance increased Inter Xeon CPU @2.6Ghz(4 Procceser) 64GB RAM 4TB Disk For GPRC CMA/NSMC and thredds This server will act as the ‘Asian hub’ of the GSICS collaboration servers’ network Website: http://gsics.nsmc.cma.gov.cn/thredds/catalog.html

CMA GSICS Product CMA NRTC Product Available CMA has produced demonstrational Near Real Time Correction (NRTC) GSICS products for the FY2D, FY2E & FY2F IR channel cross calibrated using the Metop-A IASI instrument.   Thanks for the meta-data content and data structure validation work by Masaya Takahashi@JMA. FY-3C/MERSI/VIRR/IRAS LEO-LEO IR NRTC products are also being tested and will be on line in the near future

Fengyun LEO FY-3A (mid-morning) was launched in 2008, FY-1: Retired FY-3: 2nd Generation FY-3 has 11 Instruments Atmospheric sounding Microwave Imaging Ozone sounding Radiation budget for Earth system Spatial Resolution from 1 Km to 250m Global data acquisition latency : 1.5 hours ok FY-3A (mid-morning) was launched in 2008, FY-3B (Afternoon) was launched in 2010, FY-3C (mid-morning) was launched in 2013. VIRR: Visible and Infra-Red Radiometer MERSI: Medium Resolution Spectral Imager IRAS: Infrared Atmospheric Sounder MWTS: MicroWave Temperature Sounder MWHS: MicroWave Humidity Sounder MWRI: MicroWave Radiation Imager SBUS: Solar Backscatter Ultraviolet Sounder TOU: Total Ozone mapping Unit SIM: Solar Irritation Monitor ERM: Earth Radiation Monitor SEM: Space Environment Monitor Prototype structure of FY-3 21 21

Intersection between the Line of sight and the Earth Figure FY-3 Data Geolocation FY-3C was launched on 23th Sep. 2013. All 9 payloads’ data geolocation have been done with multi-thread in the ground operational system. Instrument Level Satellite Level Line of sight Intersection between the Line of sight and the Earth Figure

Fig.1 Mis-alignment Parameters Equation FY-3 Geolocation Mis-alignment Fig.1 Mis-alignment Parameters Equation Idea line of sight Real line of sight Satellite position Satellite Earth Green：orignal static file Blue：correctted static file Fig.2 Static File Correction Fig.3 DEM Correction 1、FY-3 Geolocation Accuracy： It has been found that FY-3 geolocation accuracy has achieved ±1pixel over the swath. 2、Both the global and local processing software have been updated. The European Direct Broadcasting User can also using the software.

Thank you for your attention! Lei Yang National Satellite Meteorological Center, China Meteorological Administration yangl@cma.gov.cn