An extended ambiguity criterion for array design

The ambiguity problem in direction-of-arrival (DOA) estimation using a sensor array, manifests itself as spurious peaks in the DOA spectrum, making the true targets indistinguishable from the false alarms. A criterion that determines the presence of certain ambiguities inherent to a symmetric linear array has been proposed in the literature (Manikas, A. and Proukakis, C., IEEE Trans. Sig. Processing, vol.46, no.8, p.2166-79, 1998). The criterion is a useful tool to design reliable sensor arrays. A generalization of this ambiguity criterion is presented. The new ambiguity criterion encompasses more ambiguous DOAs and therefore gives a more accurate measurement of the reliability of an array design.