ASA 126th Meeting Denver 1993 October 4-8

4pUW1. Serpentine array processing.

J. Robert Fricke

Dept. Ocean Eng., MIT, Rm. 5-218, 77 Massachusetts Ave., Cambridge, MA 02139

Often one must determine the wave-number spectra of complicated spatial wave fields, which contain significant energy propagating in a broad range of directions. In this case a single linear array must be steered to endfire to compute some of the wave numbers of interest. To alleviate this need a multilinear array, e.g., a Mill's Cross, is often used. This paper discusses a broadband wave-number spectral estimation methodology wherein the array elements may be placed in an arbitrary serpentine pattern. The array processing technique is a modified radon transform for serpentine arrays, which may be interpreted as a plane wave decomposition. The elements of the serpentine array are projected onto virtual linear arrays steered in the intended direction for plane-wave estimation. A weighting function is computed to compensate for multiple serpentine array segments being projected onto a single virtual array segment. The compensation varies with each steering angle. The length of the virtual linear array at each steering angle determines the resolution of the serpentine array. [Work supported by ONR.]