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IR Calibration Monitoring System for COMS in Korea. Sung-Rae Chung, Hye-Sook Park*, B. J. Sohn*, Mi-Lim Ou Korea Meteorological Administration *Seoul National University. 1. Outline. Overview of Communication, Ocean and Meteorological Satellite (COMS) COMS Calibration System
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IR Calibration Monitoring System for COMS in Korea Sung-Rae Chung, Hye-Sook Park*, B. J. Sohn*, Mi-Lim Ou Korea Meteorological Administration *Seoul National University GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT 1
Outline • Overview of Communication, Ocean and Meteorological Satellite (COMS) • COMS Calibration System • IR Calibration Monitoring System for COMS • Future Works GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Overview of Communication, Ocean and Meteorological Satellite (COMS) GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Geostationary Ocean Color Imager (GOCI) S-Band Antenna Meteorological Imager (MI) Ka Band Antenna Flight Configuration of COMS GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Meteorological Imager (MI) GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
COMS L1B data Scene Analysis : Special mode AMV COMS Meteorological Products GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Future COMS Operation Center GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
COMS Calibration System GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Daily data acquisition COMS counts Geometric data MODIS radiances Geometric data On-board Blackbody data Space look data Scene check Clear Clear Cloudy Clear VISCD IRC VISCO VISCC IR Calibration Equation VIS Vicarious Calibration IR Calibration Monitoring Cloud Target Desert Target Ocean Target Simulated radiances vs COMS counts COMS counts vs MODIS brightness temp. Twice a month IR Calibration coefficient VIS Calibration coefficient Monitoring parameters (Mean Bias,RMSE) COMS Calibration Algorithm GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Simpson Desert (Australia) Calibration Targets COMS VIS Calibration Targets GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Daily mean MODIS Reflectance Simulated reflectance Reflectance 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 Julian day in 2004 Results of VIS Calibration 5-day average Ocean Target Desert Target CloudTarget GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
IR Calibration Monitoring System for COMS GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
IR Calibration Monitoring Monitoring COMS MI brightness temperatures through the intercomparison with temperatures from well-calibrated sensors. Here, COMS algorithm is applied to MTSAT-1R with MODIS as a reference. That is, TB’(GEO) = a + b *TB(MODIS) TB(GEO) vs. TB’(GEO) GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Geostationary Satellite (MTSAT-1R) Polar orbital Satellite (MODIS/Terra) Match-up Conditions • Observation time difference - Maximum time difference is within 5 min • Target • - Selection clear or homogenous target • Spatial resolution difference - MODIS: 1km, MTSAT-1R: 4km - Average over pixels of 0.2° resolution • Viewing angle (VA) difference - The viewing angle difference changes the effect of atmosphere - Data are selected within 50° of satellite viewing angle from nadir (M. König, 1999) - Maximum viewing angle difference is within 5° GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Window CH1 Window CH2 SWIR CH WV CH Spectral Channel Characteristics GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
R : radiance at the top of the atmosphere Φ : spectral response function ν : wavenumber Development of Transfer function • For the simulation of brightness temperature, RTTOV-7 model used with Thermodynamic Initial Guess Retrieval (TIGR) 2000 profile data as inputs. • Instrument random noise are added by assuming a normal distribution of the noise with zero mean and 1 standard deviation equal to the NEdT • Simulations and regressions are made at every 5 viewing angle and over land and ocean, separately. • Convert MODIS brightness temperature into MODIS equivalent MTSAT-1R brightness temperature TB’MTSAT = a + b *TBMODIS : Transfer function GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Results • Period : August 2005 ~ August 2006 (13 months) • Region : 40°S – 40°N, 100°E– 180°E • IR calibration monitoring every week - For the SWIR channel, only nighttime data are used GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Inter-Calibration of MTSAT-1R 13 months (Aug. 2005 – Aug. 2006) Window CH2 Window CH1 Before: 2005.8.1 - 2006.2.18 Correct 1: 2006.2.19- 6.30 After: 2006. 7.1 - 8.31 SWIR CH WV CH GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Weekly Calibration Monitoring From Puschell et al. (2006) GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Future Works • Test COMS calibration system • Standardize and improve the system • Formulate the IOT plan for calibration • Intercompare to the hyperspectral sensor for COMS IR calibration monitoring GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT
Thank you! GLOBAL SPACE-BASED INTER-CALIBRATION SYSTEM (GSICS) Joint Meeting of GDWG-I and GRWG-II, 12-14 June 2007, EUMETSAT