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/μm~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.