Analysis of GRACE Follow-On Laser Ranging Interferometer Derived Inter-Satellite Pointing Angles

Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) was launched on May 22, 2018. It carries the Laser Ranging Interferometer (LRI) as a technology demonstrator that measures inter-satellite range with nanometer precision using laser-link between satellites. To maintain satellites, LRI uses beam steering method: Fast Steering Mirror (FSM) is actuated to correct for misalignment incoming outgoing laser beams. From FSM commands, we can compute pitch yaw angles. These angles provide information about spacecraft's relative orientation respect line-of-sight (LOS). We analyze derived pointing 2019 2020. Further, present its comparison from GRACE-FO SCA1B data, which represents spacecraft attitude computed star cameras Inertial Measurement Unit (IMU) data Kalman filter. discuss correlations seen based temperature variations. This analysis serves basis explore potential of this new product obtained Differential Wavefront Sensing (DWS) control FSM.