A non-coherent approach to focused underwater imaging

This paper describes a non-coherent correlation technique for the formation of focused acoustic images, mainly for underwater applications. The technique is applied to the envelope of signals received by an array. The performances of the technique (lateral resolution, depth of field, accuracy of range determination, and speed of the imaging process) are estimated and compared with those of focused beamforming. The absence of grating lobes, for whatever arrangement of the transducers, and a high speed are the two major advantages of the proposed technique. The results of some simulations are reported and compared with those obtained by the beamforming process. >