Sonar array processing borrows from geophysics

A modification of a simple hybrid signal-processing technique introduced in 1973 by Tad Ulrych, a geophysicist, and his colleagues is described. The method can improve the performance of one-dimensional, equispaced sensor arrays under certain conditions, so that they perform as well as arrays that are up to two or three times longer under high signal-to-noise ratio conditions. Combining approaches used in traditional Fourier analysis (which gives good results only for weak signals) and high-resolution signal processing (which resolves only strong signals well), the technique yields enhanced resolution for both. The application of the hybrid technique to sonar processing is described.<>