Above-the-Horizon Coverage for Satellite Constellations with Dual-Altitude Band Constraints Using Ring-Based Discretization

For observation against a space background, satellite constellations, as a complement to traditional ground-based observation systems, have advantages in flexibility and observing performance, especially for very small space objects. The coverage of this kind of constellation is a typical above-the-horizon (ATH) problem. This study focuses on the three-dimensional ATH coverage for satellite constellations with dual-altitude band constraints and a prespecified sensor range. A rapid coverage calculation method is first developed for a single satellite by discretizing the target region into ring elements of equal volume. This treatment significantly reduces the computational load because the angular coverage interval of the centerline of each ring element can be analytically derived. The method is then extended to satellite constellations by using the superimposing law along the centerline. In this manner, both the onefold and multifold coverages of the constellation can be determined. Finally, a comprehensive comparison with existing models is performed, demonstrating the effectiveness and computational efficiency of the proposed method.