An Advanced Technology of Absolute Radiometric Calibration for Optical Remote Sensors

For sensor radiometric calibration,there are source-based radiometry which is based on blackbody physics referenced to the freezing temperature of gold,and detector-based radiometry which is based on electrical substitution radiometer at cryogenic temperatures respectively.The source-based radiometry is a traditional method with poor accuracy compared to detector-based radiometry owing to the difficulty of high accuracy measurement of blackbody temperature.With the development of multi-spectrum,multi-platform and high-resolution response remote sensors,the traditional absolute radiometric calibration technology source-based is facing the challenge since it accuracy doesn't meet the remote sensing application requirements.In this paper,a new calibration method and its application technology based on radiance standard detector are presented in detail.The absolute accuracy of the new calibration technology is far higher than before,since it can directly trace to the cryogenic absolute radiometer which measures the radiant power with the lowest uncertainties currently.The new calibration method has been successfully used to FY-2 No.04 and No.05 satellite sensor preflight absolute calibration two times in KunMing in 2004.The results show that the new method can effectively improve the calibration accuracy of satellite sensors and has potential applications in preflight,on-board and vicarious calibration of sensors.