Spectral observations of geostationary satellites

One of the main tasks of the situational awareness system in near-Earth space is to determine the type and class of observed objects by analyzing its reflection spectra. This paper proposes a methodology and interpretation of the spectral observational data of geostationary orbit satellites obtained at the Tian Shan Astronomical Observatory (Kazakhstan) from June-December 2021. 8 geostationary objects, the type and design features of which are known were selected as observation targets. The selected satellites are stable (no fast rotation of these objects was detected) and have large reflecting surface areas. An analysis of the obtained reflection spectra shows the dependence on the phase angle of the object. The studies carried out are especially relevant for objects in high orbits, where the only currently available methods of detection and study are ground-based optical photometry and spectroscopy using meter-class telescopes.