Eigenstructure methods for array sensor localization

The problem of localizing the array sensors, relative to a reference sensor, using planar wave-front, is formulated and studied by analyzing the eigenvectors and eigenvalues of the sample covariance matrices. "Observability" of the sensor locations requires a minimum of two calibrating signals with known direction of arrival. We consider three types of calibrating signal in accordance with whether it can be timely turned on and off or whether it appears alone in a frequency bin. The technique of covariance differencing (or despoking) and an iterative method are used to treat separately or jointly these different types of signal. The ambiguity resulting from taking phase delay modulo 2π and the rank-2 ambiguity of the array manifold parametrized by the phase delay are characterized and eliminated in our algorithms.