Antenna tracking profile generation using mixed-integer linear programming

Abstract

The increasing demand for the improved quantitative and qualitative performance of Earth observation images requires an increase in image data sizes and satellite agility, and that requires an increased effectiveness of antenna operations transmitting data to a ground station. Here, a mixed-integer linear programming (MILP)-based algorithm generating a tracking profile for an antenna subjected to operational constraints was utilized to maximize data transmission time. The constraints included angle and angular velocity limits. This algorithm considers a transition between two sets of angles for the elevation-over-azimuth mechanism to avoid rapid movement. Data transmission angle ranges are depicted as polygons representing the mission environment as mathematical equations in the MILP model. To reduce computation time, two assumptions were applied to simplify the algorithm, which extracts sampling points that can represent interior points. The proposed algorithm was verified by general imaging mission scenarios from a high-mobility satellite with special mission scenarios (i.e., worst-case scenarios for antenna maneuvers). The results were then compared with the preliminary tracking profile from the ground station searching method, which is a heuristic method. The MILP-based algorithm created solutions where data could be transmitted for 97.87% of the entire contact duration; total maneuvers of azimuth and elevation angles averaged at below 45.49% and 60.88% than of those constantly directed at the ground station, respectively. Operational constraints were satisfied in all scenarios, confirming that the algorithm is well suited to both general and worst-case scenario missions.