A limitation of the Kumaresan-Prony algorithm in direction-finding applications

A modification of the forward-backward linear prediction method of spectral analysis due to Tufts and Kumaresan was evaluated for use in direction finding with an array of sensors. A special case of this method, called the Kumaresan-Prony case, is especially attractive due to its ease of computation. This case, however, was found to exhibit blind angles, where performance was severely degraded in spite of wide spacing of the sources. The locations of these blind angles are functions of the relative phase of the two sources, and of the ratio of the physical length of the array to the length of the modulation envelope set up by the interference of the two incoming signals.