Use of the Barankin bound for determining the threshold SNR in estimating the bearing of a source in the presence of another

In this paper we report results of a research in which we studied the problem of determining the threshold signal to noise ratio (SNR) between large and small errors estimation of the direction of arrival (DOA) of a radiating, far-field source in the presence of another. Using the Barankin lower bound (BB) we examine the conditions under which achievable mean square error (mse) performance of any unbiased DOA estimator deviates substantially from the Cramer-Rao lower bound (CRB). We present expressions for the threshold SNR as a function of the source-array geometry and the sources SNR where one and two sources, of known/unknown spectral parameters and DOAs, are present.