A satellite constellation design for enhanced navigation availability in the Korean region

In this study, an eight-satellite regional navigation satellite system (RNSS) constellation—comprising three geostationary orbit (GEO) satellites and five inclined geosynchronous orbit (IGSO) satellites—is designed to enhance navigation availability across the Korean region. The constellation prioritizes robust position dilution of precision (PDOP) availability, considering both scheduled orbit control maneuvers and unexpected satellite failures. The baseline constellation, with all five IGSO satellites clustered around a central longitude of 127°, experienced significant performance degradation when either the eastern or western GEO satellite became unavailable. To address this issue, the proposed constellation strategically positions two IGSO satellites in the eastern and western regions. The expected PDOP availability, a critical performance metric, was calculated for each scenario, incorporating state probabilities derived from constellation availability. As a result, the proposed constellation achieves an expected PDOP availability of 99.21%, a substantial improvement over the baseline constellation's 94.85%. This enhancement underscores the new RNSS constellation's potential to deliver more reliable navigation services across the Korean region.