Onboard absolute radiometric calibration and validation of the satellite calibration spectrometer on HY-1C.

As the reference radiometric calibration standard of sensors on the Haiyang-1C (HY-1C) satellite platform, the satellite calibration spectrometer (SCS) is equipped with an onboard calibration system composed of double solar diffusers and an erbium-doped diffuser to monitor the postlaunch radiometric response change. Herein, through onboard calibration data analysis, the calibration diffuser performance remains stable without degradation, and the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra is adopted as a reference to repeatedly verify onboard radiometric calibration results by selecting different dates and reflectance scenes. The SCS equivalent reflectance is obtained by combining the mean digital number (DN) of the SCS crossing area image with the radiometric calibration coefficient.

The Research of On-Orbit Calibration Method Based on Solar Diffuser.

As one of the most important ways of improving the calibration accuracy at present, the calibration method based on a solar diffuser(SD) is an independent calibration way with advantages of high accuracy, high frequency and high efficiency . The principles, methods and implementation process of on-orbit calibration based on the SD is described in this thesis. The radiance reference for calibration in space is found and the physical model of the on-orbit reflectance calibration is provided.