SENSITIVITY ANALYSIS OF THE MAXIMUM-LIKELIHOOD DIRECTION-FINDING ALGORITHM

The maximum likelihood (ML) technique has been proposed for estimating the directions-of-arrival (DOA) of narrowband signals received by a sensor array. A first-order analysis is performed of the sensitivity of the ML direction-finding algorithm to system errors which cause differences between the array manifold used by the algorithm and the true array manifold. The effect of such errors on the DOA estimates is investigated. The ability of the ML algorithm to resolve two closely spaced sources in the presence of phase and gain errors in the array elements or in the receivers, or errors in the element locations, is analyzed. A formula for computing the failure threshold of the algorithm as a function of source separation and other system parameters is derived and tested by simulation. The analysis assumes that the exact covariance matrix of array element outputs is known (the infinite data case). © 1990 IEEE