Modulo conversion method for estimating the direction of arrival

A modulo conversion method for resolving phase ambiguity and consequently estimating the direction of arrival (DOA) of an electromagnetic wave incident on a multielement interferometer with nonuniform spacings is presented. The technique involves a step-by-step reduction of the number of ambiguities in the measured phase difference of the longest interelement spacing. A major advantage of this method is that even the shortest interelement spacing can be larger than half-wavelength.