In-flight attitude perturbances estimation - Application to PLEIADES-HR satellites

This paper deals with the problem of retrieving attitude perturbances in the framework of the PLEIADES-HR optical satellites. Thus, two complementary methods are compared. The first one uses the high agility capacity of satellites to acquire stars in an inertial steering mode. The second method exploits the fact that multispectral CCD arrays are shifted in the telescope focal plane in the velocity direction: for a same ground point, the resulting images are not affected by the same attitude perturbances. The resulting misregistrations can be exploited to deduce information about the attitude platform. Both methods have been applied to PLEIADES-HR satellites, during commissioning period.