1. A method for determining the angles of arrival of signals incident on an antenna array from directions within an angular region of interest, the method comprising: supplying outputs of antenna elements of the antenna array to each of a plurality of weight generators that respectively correspond to a plurality of look angles outside the region of interest; generating, in each of the weight generators, a set of beam-forming weights that maximizes a signal-to-interference ratio of a locally-generated signal corresponding to a respective one of the look angles; determining an annihilation operator from the sets of beam-forming weights generated by the weight generators and from beam-forming vectors representing the look angles; and applying the annihilation operator to a plurality of beam-forming vectors representing angles within the region of interest to determine angles of arrival of signals within the region of interest.