Doppler Positioning of LEO Satellites Based on Orbit Error Compensation and Weighting

Abstract

Doppler positioning using the signals of opportunity (SOP) from low Earth orbit (LEO) satellites is a supplement and enhancement to the global navigation satellite system (GNSS). However, due to its non-navigation design, it could not obtain high-precision spatial and temporal information of satellite orbit, which significantly affects the accuracy of positioning results. To address this issue, the orbit error equivalent Doppler measurement error (OEEDE) of LEO satellites under the accuracy of auxiliary orbit information is modeled for the first time in this article. And according to this model analysis, a two-step improved positioning method based on orbit error compensation and weighting (OECW) is proposed to weaken the effect. Experiments using multiple groups of real acquired Iridium-Next and Orbcomm satellite signals have shown that the OECW method achieves higher positioning accuracy than existing methods, especially for the Iridium-Next satellite signals, where the horizontal positioning accuracy is improved by more than 70%. The OECW positioning method proposed in this article is of great significance for the performance improvement of LEO positioning systems.