Design of Regional Coverage Low Earth Orbit (LEO) Constellation with Optimal Inclination

In this study, we describe an analytical process for designing a low Earth orbit constellation for discontinuous regional coverage, to be used for a surveillance and reconnaissance space mission. The objective of this study was to configurea satellite constellation that targeted multiple areas near the Korean Peninsula. The constellation design forms part of adiscontinuous regional coverage problem with a minimum revisit time. We first introduced an optimal inclination searchalgorithm to calculate the orbital inclination that maximizes the geometrical coverage of single or multiple ground targets. Thecommon ground track (CGT) constellation pattern with a repeating period of one nodal day was then used to construct therest of the orbital elements of the constellation. Combining these results, we present an analytical design process that userscan directly apply to their own situation. For Seoul, for example, 39.0° was determined as the optimal orbital inclination, andthe maximum and average revisit times were 58.1 min and 27.9 min for a 20-satellite constellation, and 42.5 min and 19.7 minfor a 30-satellite CGT constellation, respectively. This study also compares the revisit times of the proposed method with thoseof a traditional Walker-Delta constellation under three inclination conditions: optimal inclination, restricted inclination bylaunch trajectories from the Korean Peninsula, and inclination for the sun-synchronous orbit. A comparison showed that theCGT constellation had the shortest revisit times with a non-optimal inclination condition.