3-D Underwater Imaging System

Since the experiments of Sokolov in 19301 many versions of an underwater camera have been proposed. The Sokolov technique is using an analog 2-D phonosensitive retina and, while very interesting by its real time possibilities and relative simplicity, remains limited in resolution2. More recently, the proposed techniques are using linear or 2-D arrays. The natural physical solution is to use a 2-D matricial array3,4 so that from a simple illumination of space, an adequate parallel treatment of the N2 echographic signals delivered by the elementary transducers of the array may lead very fast to a 3-D information about the illuminated space. Difficulties come from the fact that even a low value of 64 for N imposes to build a 4096 element array, connections between this array and a specific integrated circuitry able to make the parallel treatment on 4096 parallel channels and a signal treatment fast enough to reconstruct an image without losing the benefit of guasi real-time. Nevertheless, due to progress in integration, this approach may be proposed5,6.