We have proposed mobile multimedia satellite communication system designed to realize high-speed multimedia communications. This system uses a mobile network for the return link and the developed satellite-tracking antenna that receives high-speed satellite signals for the forward link. The satellite-tracking antenna, which consists of four planar antennas, measures the pointing error by the phase monopulse and has achieved the satellite-tracking control by the co-phasing combining and the mechanical drive. When the satellite-tracking antenna is applied to the car and the ship, it is necessary to decide the tracking drive angle constantly. When it is applied to the train, the satellite-tracking can be expected to be achieved by specifying the tracking drive angle in accordance with the distance because the train runs in the same route. This tracking method is called a program tracking in this paper. This paper describes the tracking drive angle and the error factor of the program tracking quantitatively. We concluded that it was possible to apply the program tracking to the train if operating rate of the system was 70% or less.
