To the problem of spectrum investigation with an on-board analyser VAR

The spectrum analysis of low frequency processes on board the satellite becomes inevitable in connection with the investigation of the thin structure of specific areas in magnetosphere, main shock wave and solar wind. The necessity to perform the analysis in a rather short period of time is a peculiarity of the thin structure investigation procedure. The evaluation of drawbacks and advantages of various spectral analysis techniques shows that the discrete Fourier transform (DFT) method is most efficient for the case. It enables us to perform a parallel analysis of several processes in different frequency subranges. The amplitudes and frequencies of polyharmonic processes and spectral power of low frequency random processes are determined. The technique described in this paper has been developed at the Institute for Physics and Mechanics of the Ukr. S.S.R. Academy of Sciences to determine the amplitudes and frequencies of the polyharmonic processes components. The analyser VAR designed at the Institute is supposed to be utilized in international cosmic tests.