Analysis of low frequency component in measurements of the angular rate and the acceleration done by the system qsam on board the spacecraft Foton-12

The paper presents the results of reconstruction of the spacecraft Foton-12 attitude motion by processing on board measurements of the Earth magnetic field strength. The motion (time dependence of orientation parameters and an angular rate) was found as a result of approximation of measurement data by functions calculated along solutions of the spacecraft attitude motion equations. The approximation was constructed by the least squares method. The found approximation of the attitude motion was used for calculation of quasi-steady acceleration component at the place of the accelerometer of the system QSAM. The results of filtering are presented for low frequency component in measurement data of the angular rate and the acceleration produced by that system. Filtering was done by use of discrete Fourier series. The comparison was done for the results of determining the angular rate and the acceleration by these different ways. The spectral analysis of low frequency component in measurement data was done. It was shown that some spectral components were in a good agreement with calculation results, but some components could not be interpreted in terms of the spacecraft attitude motion.