The Distributions of HDOP and VDOP in GNSS and a Corresponding New Algorithm of Fast Selecting Satellites

Abstract

In Global Navigation Satellite System (GNSS), the accuracy of position estimates depends upon the measurement geometry and pseudorange measurement errors. The Dilution of Precision (DOP) provides a simple characterization of the user-satellite geometry. An in-depth study of DOP distribution characteristics is conducted in this paper, with emphasis on performance bounds of Horizontal Dilution of Precision (HDOP) and Vertical Dilution of Precision (VDOP) for four satellites in varied hypothetical constellations. The distributions of HDOP and VDOP in 16 major world cities are analyzed by simulated calculations using the TLE sets of GPS satellites. According to the theoretical analyses about the distributions of HDOP and VDOP, this paper also proposes a new algorithm of fast selecting satellites based on HDOP and VDOP, which requires a shorter computing time than the general method and provides a feasible way to quickly achieve a high-accuracy positioning.