Numerical simulation of optimal deconvolution in a shallow-water environment

Abstract

<jats:p>A fast technique for deconvolving signals in a dispersive multipath shallow-water environment using inverse filters is compared with the more commonly used deconvolution technique of time reversal (also known as phase conjugation). The objective of such techniques is to improve the accuracy of sound transmission from a source array to some receiving space. Time reversal provides benefits in this regard but here the additional performance that can be gained from inverse filters is examined. Several strategies for obtaining a set of inverse filters are discussed, each aimed at improving the accuracy of the reconstruction of the desired time signals through inverse techniques. It will be shown that an “optimal” inversion (in the sense of achieving a flat system response in the frequency domain) does not necessarily achieve a realizable time domain filter. A fast field model (using OASES) of the Giglio Basin shallow-water test facility is used as the basis for evaluating the various focusing strategies for single receiver locations. It will be seen that inverse filter arrays provide enhanced temporal and spatial focusing when compared to time reversal arrays. In addition, inverse filtering allows multiple receivers to be used, thereby increasing bandwidth or improving redundancy.</jats:p>