A Design Method for Elliptical Orbit Constellations Targeting Discontinuous Regional Coverage in Environmental Monitoring

Satellite constellations are increasingly employed in regional remote sensing applications such as environmental monitoring and disaster management. However, achieving efficient and timely coverage for discontinuous regions with high revisit frequency remains a significant challenge. This study first compares low Earth circular and elliptical orbit constellations in terms of coverage performance, economic efficiency, and orbital lifetime. Based on this comparison, a dedicated design methodology for elliptical orbit constellations aimed at discontinuous regional coverage is developed. A critical Sun-synchronous repeating elliptical orbit is selected as the baseline configuration, and its key orbital parameters including the semi-major axis, eccentricity, and argument of perigee are analytically derived. Furthermore, a flexible constellation configuration model is proposed, introducing a modified Walker-inspired kn/kn/k pattern. This model establishes direct mathematical relationships between the constellation’s repetition factor, phasing parameters, and temporal coverage metrics to systematically guide the overall design process. A case study on wildfire monitoring in China’s Qinling Mountains demonstrates the feasibility and effectiveness of the proposed approach, achieving a one-hour revisit time over the target region with a 24-satellite constellation. The results indicate that the proposed methodology provides a cost-effective and adaptable framework for satellite constellation design in remote sensing applications, particularly suited to dynamic environmental monitoring and emergency response missions.