Autonomous navigation of service spacecrafts on geostationary orbit using GNSS signals

In this paper we consider the possibilities of navigation of spacecrafts designed to service artificial Earth satellites on the geostationary orbit and of space debris removal in the near-Earth space using the signals of Global Navigation Satellite Systems. We have formulated the methodology for estimation of the signals availability of navigation satellites on the geostationary orbit through the utilization of almanac of GPS and GLONASS. It has been demonstrated that in the case of reception of navigation signals, which are radiated by the antenna system within the limits of main lobe of the radiation pattern (RP), the availability of satellite navigation signals on the geostationary orbit is very low even if we utilize GPS and GLONASS simultaneously. We present the simulation results of the received on the geostationary orbit navigation satellites using the signals radiated in the main lobes in the range from ±13.8 to ±23.5° for the L1 frequency, from ±13.8 to ±26° for the L2/L5 frequencies and in the side lobes in the range from ±30 to ±60° of RP of the satellite antennas. The simulation of the navigation satellites available on the geostationary orbit is given on the 24-hour time interval. Presented results are illustrated by the calculations of number of visible satellites and by the geometric factor.