Accuracy Analysis on GDOP of Pseudolite Positioning System Based on TDOA Technology

Abstract

In the case that the GNSS satellite signal is interfered and the satellite constellation visibility is affected, an independent pseudolite navigation and positioning system can be constructed to achieve the positioning operation of the target user. This paper proposes an independent navigation and positioning system consisting of four pseudolites based on the principle of Time Difference of Arrival (TDOA). In this paper, the geometric dilution of precision (GDOP) expression of the positioning system under the TDOA technology is derived. In view of the influence of pseudolites geometric layout on GDOP, this paper proposes two layout schemes, Y-type and T-type, and simulates the distribution of GDOP values under each layout scheme. After comparing and analyzing the simulation graphs, it is concluded that the T-shaped geometric layout can significantly reduce the GDOP value compared with the Y-shaped layout.