A New Approach of Detecting NLOS Signals Based on Modified Residual Error Check

Abstract

Expanded Abstract Attached: Global navigation satellite system (GNSS) positioning has recently gained attention in the autonomous driving, machine control, and construction industries. With the development of low-cost multi-GNSS receivers and the advent of new types of GNSS, such as China's BeiDou Navigation Satellite System and the EU's Galileo, the potential of GNSS positioning has increased. In particular, the advent of a new type of GNSS directly increases the number of line-of-sight (LOS) signals under multipath conditions, such as urban canyons, and improves the positioning accuracy. Unfortunately, GNSS receivers can observe not only LOS signals, but also non-line-of-sight (NLOS) signals and LOS+reflected signals under multipath conditions. The multipath condition generally has a greater effect on the pseudorange than the carrier phase; however, the use of LOS and other signals causes large pseudorange positioning errors. Furthermore, the accuracy of the estimated receiver clock error is directly related to the accuracy of the real-time kinematic GNSS (RTK-GNSS) using GLONASS. In this research, we propose a method for detecting the NLOS and LOS+reflected signals to improve the accuracy of pseudorange positioning and RTK-GNSS using GLONASS.