Design of the coarse attitude angular rate estimator for low earth orbit satellite

It is undeniable that the satellite attitude is random just after the orbit injection from the launcher. In a phase, it is difficult to extract the full attitude knowledge of the satellite, however, it can be possible to determine the coarse attitude angular rate of the satellite using the difference of two successive magnetometer measurements. It is required to put the satellite attitude from the unknown random attitude to a predictable attitude. This filter was designed for an axially symmetric configuration with almost equal moments of inertia around all axes and diagonal matrix of inertia in previous literature. This paper presents another design for a micro satellite with different moments of inertia around all axes and non-zero off diagonal. The paper describes also the various steps to design the coarse attitude angular rate estimator for low earth satellite. Simulation results will be presented to evaluate the performance of the estimator and finally the conclusion and the annex.