On-orbit Geometric Calibration Method Based on Star Observation to Correct Thermal Deformation of GEO Optical Satellite

The thermal environment in geostationary orbit is much complicated than low orbit. Thermal deformation is a primary factor to deteriorate geometric quality of remote sensing image of geostationary optical satellite. The on orbit geometric quality testing results of the SDLT-1 satellite of China show that the light of sight (LOS) deviation in longitude and latitude are 26 pixels and 14 pixels respectively which are out of the accuracy requirement of the satellite. Therefore a novel on-orbit geometric calibration method based on star observation is proposed to correct thermal deformation of geostationary optical satellite. The images embodied stars are employed as experiment sources to evaluate the proposed method which are compared with traditional method based on landmarks. The results show that the geometric accuracy of the proposed method can achieve 3.2 pixels which are better than traditional calibration method based on landmarks.