A STEREOSCOPIC TECHNIQUE FOR SEA-FLOOR STATISTICAL CHARACTERIZATION BY ACOUSTIC REMOTE-SENSING

In this paper we present a new method for performing statistical chara cterization of underwater surfaces by acoustic remote sensing. A wideb and technique is outlined that, exploiting stereoscopic observation, e stimates the roughness height of underwater surfaces however oriented with respect to the instrument. The surface is ensonified by a wideban d signal and simultaneously viewed from two or more slightly different directions of view. The corresponding echoes are compared in the freq uency domain and a roughness estimate is obtained. Once the instrument centerband frequency has been fixed, the scale factor in the estimati on can be adjusted by varying the differences between the view directi ons. This permits a wide estimation interval, ranging from a small fra ction to many times the wavelength corresponding to the centerband fre quency. Preliminary experiments have been carried out in a water tank, and the estimated roughness values are in agreement with the theory d eveloped in this paper.