Correlator beamforming for multipath mitigation in high‐fidelity GNSS monitoring applications

Safety and security critical global navigation satellite system (GNSS) applications ensure system integrity by performing long-term monitoring to quantify and characterize GNSS signal anomalies. Multipath significantly hinders these high-fidelity signal quality monitoring applications. Besides multipath limiting antennas and sophisticated receiver signal processing, any remaining multipath is currently removed by antenna siting and azimuth/elevation masking. As urban development around airports and monitoring installations continues, these solutions may not suffice and more aggressive but cost-effective mitigation technologies are needed. This article explores the application of correlator beamforming as a potential solution. Unlike traditional multielement beamforming that requires a separate receiver front-end for each antenna element, correlator beamforming time multiplexes the received signals and performs beamforming as part of receiver correlation processing. This article shows that the multipath mitigation performance of correlator beamforming significantly exceeds a geodetic antenna and approaches that of traditional multi-element beamforming. The results presented are relevant for all GNSS monitoring applications.