Abstract: Considering the coordinate relationship among satellites of  Walkerδ constellation，a configuration maintenance strategy based on coverage performance is proposed in this paper. Coverage performance as a discriminant of strategy is obtained by an improved grid simulation method. According to the geometry relation between grid point subsatellite point，this improved method can be used to find those grids within coverage zone and obtain global coverage information. Considering J2 perturbation the nominal position of satellite is dynamic. In operation of constellation, when dissatisfied grids are found, the satellite with reduced coverage performance can be found according to its nominal positiion. The configuration maintenance will be accomplished after the target satellite is adjusted to its nominal position. A numeric simulation is given. The result demonstrates the effectiveness of the proposed strategy.

Key words: constellation, configuration maintenance, coverage performance, grid simulation