Optimal monopulse tracking of signal source of unknown amplitude

Estimation of the direction of arrival of a signal source by means of a monopulse antenna is one of the oldest and most widely used high resolution techniques [1]. Although the statistical performance of this estimation technique has been extensively investigated for decades, recent work [2] based on an analysis of the problem from the point of view of optimal detection applied to a two-sensors system, has shown that the common solution (detector/estimator) restricts the accessible performance. Indeed, changing the detector is necessary to optimize the overall performance. First derived in the particular case of Rayleigh-type signal source, this approach can be extended to the case of a signal source of unknown amplitude (including the non fluctuating case). The present paper establishes analytical performance of both new and common solutions in that case.