1. FY2-IASI and FY3C-IASI towards Demo
Na XU, Hanlie XU, Chengli QI,
Tao ZHANG, Zhe XU, Xiuqing HU
Thanks to :
Masaya Takahashi and Tim Hewison
CMA NSMC

2. Outline FY2-IASI towards Demo FY3-IASI towards Demo
NetCDF Products content
Method for Correction Coefficients and TB Bias calculation
Data sharing and web publication
FY3-IASI towards Demo
Briefly introduction to FY-3C IR sensors
LEO-LEO intercalibration method
Samples of IR calibration assessments for FY-3C
Current situation and plan of FY3-IASI products

3. 1. FY-2 NetCDF Products (Demo)
File Names and contents all follow the GSICS convention, from
Filename:
W_CN-CMA-NSMC,SATCAL+NRTC+GEOLEOIR,FY2E+SVISSR-MetOpA+IASI_C_BABJ_ _demo_01.nc
Contents:
Global attributes ;
Variations
Smoothing period:
NRTC ： t-5d to t-0
RAC ： t-5d to t+0
Refer to
Near Real Time Correction (NRTC)
Re-Analysis Correction (RAC)
Correction Coefficients
TB Scene

4. Method- Correction Coefficients
Weighted linear regression are used based on collocated radiances. The inverse of the sum of the spatial and temporal variance of the target radiance and the radiometric noise provide an estimated uncertainty on each dependent point, and is used as a weighting.
Uncertainty

5. Method- TB Bias Uncertainty Standard scene for FY-2 IR Channels
WV6.9
IR3.7
Tb_std (K)
286
285
247
RAD_std
mW m-2 sr-1(cm-1)-1
90.4
104 8
0.37
Uncertainty

6. Data Sharing NRTC products (Demo) against MetopA IASI are available.
RAC products (Demo) will be releases before this month ends.
They are downloadable from CMA’s GSICS Data and Products Server:

7. Web publication 1. Daily Near Real Time 2. TB bias re-analysis
Regression Scatterplots
Collocation map
2. TB bias re-analysis
Monthly Regression Scatterplot
Temp-dependence variation
Time series variation
3. Double difference sequence (under building)
(FY2-IASI_A)- (FY2-IASI_B);
(FY2-IASI)- (FY2-CRIS);

8. 2. FY-3C instruments
GSICS products for three instruments of FY-3C are ongoing.
IRAS: InfraRed Atmospheric Sounder
MERSI: Medium Resolution Spectral Imager
VIRR: Visible and Infra-Red Radiometer

9. LEO-LEO Intercalibration method
Weighted linear regression are used based on collocated radiances. Products are generate monthly.
Spatial distributions of cross points
FY-3C~METOP-A
ATBDs are ready, and will be submitted for review.
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

10. Products towards demo
Three kinds of figure products are planned to generate like FY-2. At present, the monthly regressions for the three sensors are available. NC and TB re-analysis products are under building follow GEO GSICS convention .
1. Monthly Near Real Time
Regression Scatterplots
Collocation map
IRAS
VIRR
MERSI

11. Summary FY2-IASI FY3-IASI FY2-IASI to Demo plan in 2015
Daily NRTC products of Demo version are ready and downloadable from CMA data server;
RAC products of Demo version are ready, and will online in two weeks;
CMA GSICS web can provide two kinds of figure products, daily NRT regression and TB re-analysis. Double difference sequence is under building.
FY3-IASI
GSICS LEO-LEO intercalibration are applied to VIRR, MERSI and IRAS.
ATBDs are ready, and will be submitted for review.
CMA GSICS web can provide monthly regression results.
NC and TB re-analysis products are under building follow GEO GSICS convention, and will be finished by the end of summer 2015.
FY2-IASI to Demo plan in 2015
Upload FY2-MetopA/IASI RAC ;
Complete FY2-MetopB/IASI NRTC and RAC products;
Test GSICS Plotting tool based on RAC;
Complete ATBDs and user guides

12. Thanks for your attention