LEO constellation design methodology for observing multi-targets

This paper is based on the second problem of the 8th China Space Trajectory Design Competition (CTOC8). The background is LEO constellation design strategy for monitoring discrete multi-targets with small satellite under J(2) model. The difficulty is that the small satellite is equipped with low-cost cameras with limited coverage ability and the targets are distributed separately in a key area, which result in long revisit time or large number of satellites based on traditional design method. In this paper, a specific LEO constellation design method is proposed to cope with the problems. First, grid search and numerical method are performed to construct a database consisting of repeating ground track orbits. Then several orbits are carefully selected by pruning method to visit each target. Finally, repeating ground track constellation is constructed to meet the maximum revisit time constraint. The present method provides a systematic constellation design methodology of remote sensing observation with limited coverage ability, and demonstrates the resulting constellation can obtain rapid revisit frequency over discrete multi-targets with the least number of satellites.