Self-contained Antenna Crosstalk and Phase Offset Calibration by Jointly Solving the Attitude Estimation and Calibration Problem

Abstract

Array processing algorithms such as direction of arrival (DOA) estimation, deterministic beamforming and null-steering as well as spoofer detection and mitigation are known to be sensitive to errors in the model for the antenna array spatial response. In particular, unknown gain and phase mismatches between antenna channels, mutual coupling between antenna elements, crosstalk-effects in the RF-Frontend and in the case of using ephemeris data as auxiliary spatial information unknown antenna array attitude can seriously degrade the performances of array-processing algorithms. This paper proposes a novel algorithm to estimate gain, phase and mutual coupling / crosstalk coefficients as well as the attitude of the antenna array by exploiting the ephemeris from each GNSS satellite that is sent along with the navigation data. The estimation of the various parameters is based on a maximum likelihood approach. Numerical results are shown to illustrate the potential usefulness of the proposed calibration algorithm toward better accuracy and resolution in deterministic array-processing algorithms