Overall Design of Fine Guidance Sensor in Attitude Determination for the SVOM Satellite

SVOM is a Sino-French cooperation project aiming at Gamma Ray Burst observation. From the top level requirement, during the observation period, the satellite platform should provide a stability of better than 1.6 arcsec/100s. Based on this severe requirement, a high precision attitude measurement device is strongly demanded. This article describes the overall design of a novel optical sensor, called Fine Guidance Sensor, for the SVOM Satellite. First, the functional and performance requirements are presented, including the extremely high measuring precision of 0.3 arcsec in y/z-axis. Second, FGS composition, including hardware and software, and processing flow design are described. Then, working mode switching logic is introduced. Next, attitude determination method and simulation result are shown. The conclusion is obtained and all the required indexes are fulfilled by current FGS design.