Characterization of GNSS measurement distortions due to antenna array processing in the presence of interference signals

GNSS signals are relatively weak once they are received on the earth surface and due to which they are very much vulnerable to intentional and unintentional interferences. Antenna array processing is a very efficient method for combating interference and jamming effects. Controlled Reception Pattern Antennas (CRPA) are capable of controlling the reception pattern adaptively such that interference can be mitigated by steering null in the direction of interference. In spite of having these advantages, these systems suffer from measurement distortions which in turn affect the navigation solution. Sources contributing to the measurement distortions include mutual coupling between antennas, radio frequency front-end delays, spatial filtering techniques and receiver processing methods. In this paper, the effects of mutual coupling between antennas and different array processing techniques on measurement bias are analyzed. The analysis is carried out through simulations and real data collected using Novatel 501 antennas.