Numerical simulation of optimal deconvolution in a shallow-water environment

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 lime reversal (also known as phase conjuga tion). The objective of such techniques is to improve the accuracy of sound transmission from a source array to some receiving space. Time reversal pr ovides benefits in this regard but here the additional performance that can be gained from inverse filters is examined. Several strategies for obtaini ng a set of inverse filters are discussed, each aimed at improving the accu racy of the reconstruction of the desired time signals through inverse tech niques. It will be shown that an ''optimal'' inversion (in the sense of ach ieving a flat system response in the frequency domain) does not necessarily achieve a realizable time domain filter. A fast field model (using GASES) of the Giglio Basin shallow-water test facility is used as the basis for ev aluating the various focusing strategies for single receiver locations. It will be seen that inverse filter arrays provide enhanced temporal and spati al focusing when compared to time reversal arrays. In addition, inverse fil tering allows multiple receivers to be used, thereby increasing bandwidth o r improving redundancy. (C) 2001 Acoustical Society of America.