3D IMAGE RECONSTRUCTION FOR SUBMERGED OBJECTS USING RAMP RESPONSE SIGNATURES

Underwater acoustical imaging techniques and the inverse analysis of acoustic scattering problems have now found many important engineering applications. Based on the physical optics approximation, the ramp response signal can be proven that it is proportional to the profile function of the scatterer, which is defined as the area of cross section of the object perpendicular to the direction of wave propagation. The image synthesis technique named as the approximate limiting surface technique is applied to generated underwater objects by using the ramp responses of the objects. The modification should be made by an iterative procedure which will adjust the parameters of each surface and will yield a result until the profile functions of this generated image at all looking angles are consistent with the input ones. Several typical objects are presented to demonstrate the process of the 3D image generation and the results indicate that the qualities of the final images are quite acceptable. The further research work is to build an automatic iterative mechanism to generate the final image for a submerged object.