of buried objects. It is designed to detect, locate and retrieve buried objects. The system is equipped with a hydraulic robot, laser range finder and a subsurface sensor. First, subsurface sensing is used to detect and locate buried objects. If an object can be reached with one dig, the excavator retrieves it directly. Otherwise a layer of soil above the object is removed and another subsurfac...

Non-invasive range and bearing estimation of buried objects, in the underwater acoustic environment, has received considerable attention (Granara et al., 1998). Many studies have been recently developed. Some of them use acoustic scattering to localize objects by analyzing acoustic resonance in the time-frequency domain, but these processes are usually limited to simple shaped objects (Nicq & B...

The main goal of this project is to increase our understanding of sound propagation in ocean bottom sediments, including ocean bottom multiphase material such as gas-bearing sediments and seagrass, which in turn benefits buried object detection, sonar operation and acoustic communications in shallow water. Another goal for the out years is to develop the proposed research apparatus into an oper...

The application of a global optimization procedure to the detection of buried inhomogeneities is studied in the present paper. The object inhomogeneities are schematized as multilayer infinite dielectric cylinders with elliptic cross sections. An efficient recursive analytical procedure is used for the forward scattering computation. A functional is constructed in which the field is expressed i...

IVe present, an efficient algorithm for computation of the maximum likelihood estimate of the location of a known target, from short. pulse scatter data. The algorithm consitutes a three step procedure: (i) data filtering. (ii) time-domain backpropagation. and (iii) coherent. summation and consists of a number of projection and backprojection operations int,egrated in a tomographic scheme. .A c...

Integration of an ultrasonically-based system for materials characterization and a hand-probe was demonstrated to have a large potential in detection of buried mines for the purpose of humanitarian demining. In the integration, the absence of interferences with the conventional, contact technique of hand-probe use was emphasized. The characteristics of buried mines severely restrict hand-probe ...

Background reverberation can obscure useful features of the target echo response in broadband low-frequency sonar images, adversely affecting detection and classification performance. This paper describes a resolution and phase-preserving means of separating the target response from the background reverberation noise using a coherence-based wavelet shrinkage method proposed recently for de-nois...

We present a statistical study of the electric field scattered from a three-dimensional penetrable object buried under a two-dimensional random rough surface. Monte Carlo simulations using the steepest-descent fast multipole method (SDFMM) are conducted to calculate the average and the standard deviation of the near-zone scattered fields. The SDFMM, originally developed at the University of Ill...