A Method for Calculating the Over-the-Top Tracking Direction of a Small Cross-Beam Airborne Satellite Antenna

The main task of the airborne satellite antenna is to calculate the pointing angle of the antenna in real time based on the target satellite information and the aircraft's position and attitude data, and to control the antenna to quickly align with the satellite and track it. When the elevation angle of the aircraft is high and the circling attitude is large, the antenna may enter the state of overshooting tracking. The commonly used A-E frame satellite antenna cannot track at high elevation angles, and the cross-axis design of the A-E-C frame airborne satellite antenna has a limited range of motion due to envelope and weight constraints. The commonly used pointing calculation method for the A-E-C frame may face limitations due to the small range of motion of the cross-axis, which cannot meet the tracking and communication requirements. This paper discusses the reasons why the commonly used tracking pointing calculation method for the A-E frame airborne antenna cannot achieve high elevation angle tracking when the aircraft is in a large attitude circling. And then it analyzes the problems faced by the commonly used tracking pointing calculation method under the premise of a small cross-axis for the A-E-C frame. Subsequently, a new tracking pointing calculation method based on the A-E-C small cross-axis frame is proposed, which can significantly improve the overshooting tracking performance of the airborne satellite antenna.