Satellite Antenna Direction Determination System Using TV Signal Strength Data and Its Verification Results

Unique system which is called as Antenna Direction Determination System (ADDS) toconfirm the real transmitting antenna direction of broadcasting satellite using TV signal strength data received at various ground stations at the same time has been developed. It is a method to be able to estimate even pointing error caused by sensor error, antenna reflector thermal distortion, etc. which can't be known by telemetry data. The principle of this method is applying the non-linear least square method against the signal strength level variation to get the movement of pre-measured antenna gain footprint. Practical antenna direction determination experiment was done using BSE launched in 1978 through its mission life. From the results of experiment in various operational condition, this system was verified for its capability and usefulness.