Bias of the Maximum Likelihood Doa Estimation from Inaccurate Knowledge of the Antenna Array Response

Abstract

The estimators of directions of arrival of narrow-band signals using array antennas could be erroneous if we do not model adequately the behaviour of the global antenna system (for example, incorrect modeling of the mutual coupling or coupling of the antennas with the platform). In this paper we obtain an expression for evaluating the bias of the Maximum Likelihood estimators if we model incorrectly the behaviour of the antenna. The results indicate that if we consider an onboard array antenna as an ideal system (without electromagnetic effects) the performance of a direction of arrivals (DOA) estimation system may be degradated.