A method of locating one or more reflectors in an environment crowded with reflectors. A transmitter and multiple receivers are used to obtain reflected signals. Each path of a reflected signal is defined by an ellipse having the transmitter at one focus and a receiver at the other. A reflector is assumed to lie on the ellipse, and an intersection of ellipses is assumed to be a reflector location. The region is iteratively divided into smaller and smaller cells, and a search algorithm is performed to determine whether a given point in each cell lies on an ellipse. A "solution" is a point that lies on the same number of ellipses as the number of receivers.
Michael A. Koets