Coherent wide-band processing for arbitrary array geometry

Abstract

We present a new method for coherent wide-band direction finding of far-field sources impinging on a two-dimensional array with a known arbitrary geometry. This method, termed array manifold interpolation (AMI), is based on obtaining the array manifold at a desired frequency f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , by linear interpolation of the array manifold at a given frequency, f. We use a separable representation of the array manifold vector, which separates the array geometry and the frequency from the direction θ, in order to derive the required array manifold interpolation matrix. The AMI method is practical, computationally efficient, and robust. For the special case of a uniform circular array, we present a fast implementation of the AMI method, which utilizes the FFT algorithm.