REAL-TIME ON-ORBIT CALIBRATION OF ANGLES BETWEEN STAR SENSOR AND EARTH OBSERVATION CAMERA FOR OPTICAL SURVEYING AND MAPPING SATELLITES

Abstract

On space remote sensing stereo mapping field, the angle variation between the star sensor’s optical axis and the earth observation camera’s optical axis on-orbit affects the positioning accuracy, when optical mapping is without ground control points (GCPs). This work analyses the formation factors and elimination methods for both the star sensor’s error and the angles error between the star sensor’s optical axis and the earth observation camera’s optical axis. Based on that, to improve the low attitude stability and long calibration time necessary of current satellite cameras, a method is then proposed for real-time on-orbit calibration of the angles between star sensor’s optical axis and the earth observation camera’s optical axis based on the principle of auto-collimation. This method is experimentally verified to realize real-time on-orbit autonomous calibration of the angles between the star sensor’s optical axis and the earth observation camera’s optical axis.