Cross-calibration of FY-2E/VISSR infrared window and water vapor channels with TERRA/MODIS

This paper addresses the cross-calibration method of infrared window and water vapor channels of VISSR (Visible and Infrared Spin Scan Radiometer) with reference data provided by the onboard geostationary satellite FY-2E with MODIS (MoDerate resolution Imaging Spectroradiometer) and the onboard polar-orbit satellite TERRA. The cross-calibration is implemented using the satellite remote date in May, July and December of 2010. The results show that the bright temperature calculated using cross-calibration coefficients is nearly equal to the observed value of MODIS for all collocation samples, and about 90 percent of temperature bias is less than 1K. It can also be seen that the calibration slope decreases obviously from May to the beginning of July, and ascends slightly in the last ten-day of July,then keeps steady in December. The variation of calibration coefficients reveals great consistent with that of remote temperatures. All in all, the cross-calibration method described here can increase frequency and accuracy, and provide a methodological foundation for on-orbit calibration of FY-2E.