Ultimate array accuracy and resolution in the presence of near-field emitters

Superresolution array processing, and in particular signal subspace-type techniques, are based effectively on the searching of the array manifold in order to estimate signal parameters. Although the array manifold concept has been used extensively to solve parameter estimation problems, only very recently has research been directed toward identifying the shape of the manifold. Knowledge of the manifold shape is not only essential for the investigation of ambiguities and assessment of the detection-resolution capabilities of an array, but it may also prove useful in developing new and more effective methods for its search process. Concepts related to two array manifold properties, namely arc length and first curvature, are used to assess the accuracy and resolution capabilities offered by a general array in the presence of near-field emitters