Coverage Analysis in Case of Faults of Some Satellites in Low Earth Orbit Satellite Constellations

In this paper we analyze the coverage performance of satellite constellation specially in low earth orbit. First of all we analyze the various possible configuration of combinations of failures of satellites in the same orbital plane or in different orbital planes when one satellite or a number of satellites are in faults. To evaluate the performances of constellation we use one parameter, which is the maximum non-visibility time at one receiver position on earth by using simulation software. Also we have simulated by varying the latitude of the receiver position from 0 degree to 90 degrees to analyze the coverage performance variations depending on the receiver position on earth. According to the results of the simulations we compare the maximum non-visibility time depending on the configuration of failure of satellites and identified the worst case of combination of satellite failures in satellite constellation. Finally we evaluate the some orbital maneuver strategy, (phase changing in the same orbital plane), to minimize the non-visibility time on earth in case of failure of number of satellites.