Performance analysis of mis-modeled estimation procedures for a distributed source of non-constant modulus

The problem of estimating the bearing of a single, far-field, non-constant modulus source, surrounded by local scatterers using passive sensor array measurements is addressed. An associated source bearing estimation problem is formulated, and the Cramer-Rao lower bound is evaluated. Estimation procedures that assume the source is of constant modulus and therefore suffer from mis-modeling errors are investigated. Specifically, the performance of the application of the maximum likelihood (ML) estimator designed for a constant modulus source performing on a non-constant modulus source is evaluated, and the exact degradation in performance is quantified as a function of the source´s empirical variance