Real-time optimal exclusive angle determination method for IGSO communication satellite

The establishment of the exclusion zone serves as an effective method to mitigate communication interference from Non-Geostationary Orbit (NGSO) satellites to Geosynchronous Orbit (GSO) satellites. The exclusion zone is typically characterized by the exclusive angle. To address the issue of the optimal exclusive angle for Inclined Geosynchronous Orbit (IGSO) satellite varying over time, this paper proposes a real-time optimal exclusive angle determination method. Initially, a dynamic model of spacecraft considering high-order gravitational perturbations and a communication interference model is established. Subsequently, a computational approach is provided to determine the optimal exclusive angle at any given moment. Lastly, through analysing the periodic motion characteristics of the IGSO satellite, an approximate function for the optimal exclusive angle’s temporal variation is derived, enabling rapid identification of the real-time optimal exclusive angle. Simulation results demonstrate that the calculated optimal exclusive angles accurately characterize the harmful interference regions. The derived approximate function for the optimal exclusive angle is in analytical form and closely matches the actual variation curve of the exclusive angle. 10-day prediction errors are less than 0.05°, while 1-year prediction errors remain under 0.1°. For prediction periods exceeding 1 year, it is recommended to update the approximate function using the latest IGSO satellite orbital elements to maintain computational accuracy.