Radiometric cross-calibration of CBERS-02 IRMSS thermal channel

TERRA MODIS band 31 was selected as the criterion for doing the radiometric cross-calibration of CBERS-02 IRMSS thermal band. From August to December, 2004, seven times day and night synchronous images of two sensors passing through the Lake Qinghai and Lake Taihu were selected to obtain the cross-calibration data. TERRA MODIS band 31 data were used to conduct out the pupil radiance of CBERS-02 IRMSS band 9 based on the two sensors' spectrum matching, and then the DN values were picked-up from the IRMSS data in the same area. A new model to calculate the radiometric calibration coefficients was carried out in this study. The model is multi-points linear regression method with 7 times day and night synchronous images at different dates and locations. The radiometric cross-calibration coefficients are 8.0567 (gain, unit: DN/(W/m(2)/sr(1)/mu m(1))) and 47.892 (offset, unit: DN). Accuracy estimate of calibration coefficients was carried out. The results show that the calibration coefficients obtained from the linear regression method have a similar precision as TERRA MODIS band 31 ' s. The calibration coefficients can satisfy the quantitative applications of CBERS-02 IRMSS thermal data.