GNSS Antenna Arrays and RTK: The Effect of Carrier Phase Distortions Induced by Spatial Filtering on RTK Positioning

Abstract

New GNSS applications demand resilience against radio interference and high position accuracy. Separately, these demands can be fulfilled by multi-antenna systems using spatial filtering and carrier phase positioning algorithms like real time kinematics (RTK), respectively. However, combining these approaches encounters a severe issue: The spatial filtering induces a phase offset into the measured carrier phase leading to a loss of position accuracy. This paper presents a new approach to compensate the phase offset in a blind manner, i.e., without knowing the antenna array radiation pattern or the direction of arrival of the signals. The proposed approach is experimentally validated in two jamming scenarios. One includes a jammer with increasing power and the other includes a moving jammer. The results demonstrate that the approach successfully compensates for the phase offset and, hence, allows the combined use of RTK positioning and spatial filtering even under jamming.