Direction-of-arrival estimation of correlated sources by adaptive beamforming

This correspondence has analyzed the capability of minimum energy optimum/adaptive beamformer to estimate the bearings of two closely spaced narrowband equal-energy correlated sources. The analytical expression for minimum angular separation for resolution of such sources as a function of the correlation coefficient, signal power, and the parameters of the adaptive processor is derived. The approach of spatial smoothing is considered. The simple problem of definition of optimal size of the subarray for highly correlated sources is examined. Results of computer simulations are included to support our analysis.