Seamless Accurate Positioning in Deep Urban Area based on Mode Switching Between DGNSS and Multipath Mitigation Positioning

TL;DR

This paper presents a real-time mode-switching technique between DGNSS and multipath mitigation to improve GNSS positioning accuracy in deep urban environments, achieving near-perfect availability and significantly reduced errors.

Contribution

It introduces a novel real-time multipath estimation and mode-switching algorithm that enhances GNSS accuracy without additional sensors or prior information in urban areas.

Findings

Availability improved from 64% to 100%.

Error RMS reduced from 11.1 m to 1.2 m.

Effective for automotive applications in deep urban environments.

Abstract

Multipath and non-line-of-sight (NLOS) signals are the major causes of poor accuracy of a global navigation satellite system (GNSS) in urban areas. Despite the wide usage of the GNSS in populated urban areas, it is difficult to suggest a generalized method because multipath errors are user-specific errors that cannot be eliminated by the DGNSS or a real-time kinematic technique. This paper introduces a real-time multipath estimation and mitigation technique, which considers compensation for the time offset between constellations. It also presents a mode-switching algorithm between the DGNSS and multipath mitigating mode and shows that this technique can be effectively utilized for automobiles in a deep urban environment without any help from sensors other than GNSS. The availability is improved from 64% to 100% and the error RMS is reduced from 11.1 m to 1.2 m on Teheran-ro, Seoul, Korea. Because this method does not require prior information or additional sensor implementation for high-positioning performance in deep urban areas, it is expected to gain wide usage in not only the automotive industry but also future intelligent transportation systems.