Direction finding with fewer receivers via time-varying preprocessing

We present a new technique for localizing multiple narrowband sources by a passive sensor array based on dimensionality-reducing time-varying preprocessing of the sensor outputs. The technique allows a significant reduction in the number of receivers required for the implementation with only two receivers sufficing in the extreme case. The estimation method we use is based on approximating the corresponding maximum likelihood estimator by a computationally simpler generalized least squares (GLS) estimator that is proved to be both consistent and asymptotically efficient. Simulation results confirming the theoretical results are included