Abstract：Since the KBR phase center and the installation matrix of the star sensor may change after the satellites enter the orbit, there will be a systematic bias of the inter-satellite pointing of GRACE-FO satellite. In order to correct the bias, it is necessary to uplink the inter-satellite pointing calibration parameters into the satellite attitude and orbit control system. In this paper, we derive the correlative algorithms of inter-satellite pointing calibration and accuracy evaluation, and propose the process and implementation strategy of inter-satellite pointing calibration based on in-flight path. Based on the post-processing path, we evaluate the inter-satellite pointing performance of GRACE-FO since its launch. The STD and RMS of the inter-satellite pointing angle indicate that the GRACE-FO inter-satellite pointing meets the requirements of pitch and yaw direction 1 mrad and roll direction 10 mrad for the normal operation of KBR. The magnetic torque of the satellite attitude and orbit control system and the attitude control thruster can meet the requirements of attitude control.
