Carrier-Phase-Based Quality Control for GNSS Dynamic Relative Navigation

Abstract

Carrier-phase-based global navigation satellite system (GNSS) dynamic relative navigation is essential for fields that require high integrity and accuracy. Code-based receiver autonomous integrity monitoring (RAIM) has been studied extensively; however, carrier-phase-based integrity monitoring requires further study to meet the requirements of high-performance navigation. This paper proposes a quality-control method for carrier-phase-based GNSS relative navigation. It proposes the double difference (DD) model of carrier-phase-based relative navigation, which includes high-integrity difference navigation architecture and a novel closed-loop extended Kalman filter (EKF) using partial ambiguity resolution. Quality-control procedures based on least-squares principle are extended to EKF, in which fault detection using carrier-phase-based RAIM (CRAIM) and fault identification using a double w-test are carried out, and the integrity performance of reliability and separability are studied. The field trial data are tested and analyzed, and it is shown that the proposed method is able to detect and identify both step and ramp failures. The proposed method can be used not only for code measurements but also for carrier-phase measurements, thus improving the performance of GNSS relative navigation significantly.