Selection of satellites based on the carrier phase lock indicator for enhanced RTK-GNSS

Abstract

Real-time kinematic - global navigation satellite systems (RTK-GNSS) provide positions with centimeter error; however, performance in urban area is degraded by multipath error. Common approaches to mitigate multipath are satellite selection based on SNR values or classification of LOS and NLOS signals. In this study, carrier phase lock indicator and elapsed epoch when it is invalid was used to select satellites. Car experiment was done around Tokyo station for 1 hour. Results showed increased correct fix up to 273 epochs while wrong fix was maintained below 1% of the total fix data. Increased ratio values for ratio test were also observed.