Determination of the Range of the Spacecraft

As a result of the gravitational attraction of the Sun/Moon/Earth, the pressure of solar radiation and other factors, the spacecraft located in the geostationary orbit deviates from the real orbit. The position of the spacecraft is regulated by a short pulse switching by correcting engines. This requires highly accurate measurement of the range to a spacecraft located in a geostationary orbit. The article describes a method for measuring the range not only by rangefinder, but also by command signals of the tracking, telemetry and command subsystem of a spacecraft, which allows for continuous measurement. Due to the fact that the reserves for improving the accuracy of measuring the range of a spacecraft, with known limitations as part of a single ground station, are almost exhausted, one of the perspective ways to solve this problem has been proposed. It consists of using several satellite earth stations, which are stationary located at various known locations on the Earth's surface and which receive any signal transmitted by a spacecraft located in a geostationary orbit. This method eliminates the using of special ranging signals and antennas of large diameter. For high-precision range measurement, synchronization of generators of a satellite earth stations by time signals transmitted by GLONASS or GPS navigation satellites is required. In addition, the using of various types of signals for determining the range, when measuring the delay time or phase difference, is considered. Relevant conclusions are made.