A New Approaches for Satellite Constellation Design to Regional Coverage Using GDOP

Coverage of ground stations by satellites is a very important factor to access geographic, geotechnical and strategic information. This is generally achieved by one or more satellite with specified position and navigation. In this regard, in the area of low altitude orbits regional or global coverage of the Earth's surface is achieved utilizing various mathematical methods to change the position and arrangement of satellites. In this study, the arrangement of certain number of satellites is performed to reach maximum coverage. It is assumed that the satellite constellation is in the symmetrical Walker pattern. In this regard, taking into account the situation of user and determining the initial position of satellite in system, Geometric Dilution of Precision (GDOP) parameters are calculated utilizing a new model. The innovation in this new presented model is employing GDOP in an inverse manner. GDOP is a geometric standard that the less related values for it represents more accuracy in determining the amount of coverage. In this study the effects of compression of the earth as well as chamfer are considered. The calculations are presented for specific geographic areas and only for one day. The results show that by taking advantage of new computing model, the coverage area will dramatically increase. By organized employing of all the satellites in the constellation, with the best received Information from satellites, better coverage can be achieved.