Na XU Xiuqing HU Lin CHEN Ling SUN NSMC CMA 2014-3-27 Long-term monitoring of FY-2 and FY-3 IR calibration using GSICS products Na XU Xiuqing HU Lin CHEN Ling SUN NSMC CMA 2014-3-27

Outline Current Status IR Bias monitoring of FY-2 VISSR IR Bias monitoring and correction of FY-3A&B MERSI and VIRR GSICS support to On-orbit test of FY-3C Future Prospects

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.

IR Calibration Bias of FY-2 VISSR FY-2 vs IASI+AIRS Significant progresses were made in FY-2 operational calibration (Changed to GSICS in 2012) Eclipse Phase GSICS Operational calibration of FY-2D/2E was upgraded using GSICS inter-calibration algorithm in 2012-04 and 2012-01 separately. The calibration biases were sharply decreased, and reduced to about 0.5~1K@290K (@250K）without eclipse period. GSICS Time series of TBB biases for IR1~3 channels vs AQUA/AIRS reference scenes (290 K for IR1 and IR2, 250 K for IR3).

IR Calibration Bias of FY-2 VISSR GSICS CIBLE 2012 2013 Significant progresses were made in FY-2 operational calibration (Changed to CIBLE in 2013) IR biases of the New operational calibration ： Seasonal variation: FY-2D biases, IR1 ( 1~2K), IR2 ( 2~3K), IR3(0.5~1K)；FY-2E biases , IR1 (-1~-0.5K), IR2 ( 1~2K), IR3(-3~-2K)；FY-2F biases , IR1 ( 1~2K), IR2 ( 2~3K), IR3(0.5~1K)； Inconsistent and systematic bias between IR bands [（VISSR-IASI) _IR1- （VISSR-IASI) _IR2] Time series of TBB biases for IR1~3 channels vs IASI and AIRS reference scenes (@290 K for IR1 and IR2,@ 250 K for IR3). Op. Cal Upgrade date：FY2D 2013-05-21; FY-2E 2013-03-27 CIBLE (Calibration of Inner Blackbody corrected by Lunar Emission )

IR Calibration Bias of FY-3 Based on LEO-LEO SNO intercalibration method, IR calibration biases of FY-3A&B VIRR and MERSI are assessed Spatial distributions of cross points FY-3B~METOP-A Temporal distributions of cross points Collocation criteria: Observation time difference < 300s Spacial Distance <1km geometry difference |cos(FY_zen)/cos(REF_zen)-1| < 5% Environment uniformity check RSTD (FY3 in ENV_BOX) < 0.005

IR Calibration Bias of FY-3A&B VIRR FY-3A&B/VIRR vs METOP-A/IASI FY3A/VIRR SRF FY3A/VIRR Scene Temp-dependence and Seasonal variation FY3B/VIRR FY3B/VIRR FY-3B/VIRR Measurements are more consistent with IASI Time series of VIRR Monthly Mean Bias versus IASI BT comparison (Right) as well as their observation differences (VIRR-IASI) in Aug. 2012

Improvement to nonlinear correction of FY-3A VIRR Channel 4 BT biases scatter of FY-3A/VIRR using nonlinear correction coefficients before and after improvement Channel 5 Before After Normalized PDFs of FY-3A/VIRR BT biases in different months using different nonlinear correction coefficients

IR Calibration Bias of FY-3A MERSI FY3A/MERSI vs METOP-A/IASI Measurements from FY-3A/MERSI are warmer than that from IASI. Annual mean bias is 3.17 ±0.35K in 2012,which is consistent with the assessment from CRCS synchronous in situ measurements. The BT biases show seasonal variation. BT comparison (left) as well as their observation differences (VIRR-IASI) in Aug. 2012 SRF Time series of VIRR Monthly Mean Bias versus IASI

FY-3C On-orbit Test—IR calibration assessment FY-3C/MERSI vs METOP-A/IASI Mean Bias 0.57±0.29K FY-3C/VIRR vs METOP-A/IASI Mean Bias CH4：-1.01±0.47K CH5：-0.95±0.38K Dec. 2013

FY-3C On-orbit Test—IR calibration improvement Onboard BB Radiance is recalculated using PRT physical temperature VIRR vs IASI Channel 4 -0.47K VIRR vs MODIS -0.44K

FY-3C On-orbit Test—IR calibration improvement Onboard BB Radiance is recalculated using PRT physical temperature VIRR vs IASI Channel 5 -0.40K VIRR vs MODIS -0.41K

FY-3C On-orbit Test—VNIR calibration coefficients CH12 CH14 CH15 Differences between FY-3C/MERSI and TERRA/MODIS measurements due to spectral mismatches simulated using GOME-2 <2% CH12：~6%; CH14：~8%;CH15：~20%

FY-3C On-orbit Test—VNIR calibration coefficients Regression between collocated FY-3C/MERSI DN and TERRA/MODIS reflectance（2012-12-28）

FY-3C On-orbit Test—VNIR calibration coefficients Nonlinearity or inconsistency using various references StableTargets Intercalibration of FY-3C/MERSI based on various targets（2012-12-28） Stable Targets: MultiSite (Dunhuang , Libya1, Libya4, Arabia2, Lanai), DCC, Moon

Chinese Meteorological Satellite: FengYun Series Polar System Geostationary System FY | 2A 2B 2C 2D 2E 2F … 2H FY | 1A 1B 1C 1D First Generation First Generation FY | 3A 3B 3C 3D … 3F Based on the current generation of polar and geostationary systems, since 1990s, we began to develop the next generation both for polar and Geo, which called FY3 in polar series, and FY4 in Geo series. FY | 4A 4B 4C … 4F Second Generation Second Generation 16

Future Prospects — CMA GSICS Products FY-2 FY-4 FY-3 REF IASI,CrIS,VIIRS,GOME… GEO-LEO-GEO GEO-GEO LEO-GEO LEO-GEO-LEO Inter-Platform LEO-LEO VNIR: Tracking and RayMatch using stable targets（Desert, Snow, DCC, Moon…）

Thanks for your attention!