Minimum of GDOP of Satellite Navigation and Its Applications in ISL Establishment of Walker-δ Constellation

摘要

GDOP is one of the important standards which measure the accuracy of a navigation positioning system. Firstly, this article discusses the shortcomings in the domestic and foreign literatures of deriving the minimum of GDOP. The existing theories of minimum of GDOP are all based on the observations of ground stations, and the deduced GDOP minimum value cannot be reached because the observable range of the receiver do not be considered. Then, the minimum GDOP is derived under the condition which the cutoff angle of satellite is greater than zero, and a method to get the minimum GDOP is proposed and the corresponding geometry between satellites is given. This new theory of minimum of GDOP is also applied to the criteria for inter-satellite link establishment in Walker-δ constellation which is proposed by the authors. The optimal structure diagram of inter-satellite link is given in terms of GDOP. Finally, computations indicate the effective and useful of this new theory of the minimum of GDOP.