3D Contour Shaping of Buried Objects in Soil

The basic question of this paper was, whether a detected anomaly found in the ground during an explosives disposal process is actually a non-detonated bomb or non-dangerous metallic scrap. Based on a borehole radar, an approach is to be presented in which first a 2-dimensional contour of the object is created with the aid of a spatial runtime evaluation. By repeating this step at different depths with subsequent graphic overlay, a 3D shape of the buried object is created. The method is first tested using a simulation model with inhomogeneous soil. In the second step the method will be applied and evaluated using a field measurement of a real object. The results shows that both 2D and 3D evaluations reflect the position and orientation of the object. Furthermore, the shape and the dimensions can be estimated, with the restriction that the 3D contour has distortions along the vertical axis. The aim of this work is to show an application of borehole radar, with which the identification of buried objects should be facilitated.

An Inverse Mixed Impedance Scattering Problem in a Chiral Medium

An inverse scattering problem of time-harmonic chiral electromagnetic waves for a buried partially coated object was studied. The buried object was embedded in a piecewise isotropic homogeneous background chiral material. On the boundary of the scattering object, the total electromagnetic field satisfied perfect conductor and impedance boundary conditions. A modified linear sampling method, which originated from the chiral reciprocity gap functional, was employed for reconstruction of the shape of the buried object without requiring any a priori knowledge of the material properties of the scattering object. Furthermore, a characterization of the impedance of the object’s surface was determined.

Proposal of UWB-PPM with Additional Time Shift for Positioning Technique in Nondestructive Environments

The ultra-wide band (UWB) technology has many advantages in positioning and measuring systems; however, powers of UWB signals rapidly reduce while traveling in propagation environments, hence detecting UWB signals are difficult. Various modulation techniques are applied for UWB signals to increase the ability for detecting the reflected signal from transmission mediums, such as pulse amplitude modulation (PAM), pulse position modulation (PPM), and so on. In this paper, we propose an ultra-wide band pulse position modulation technique with optimized additional time shift (UWB-PPM-ATS) to enhance the accuracy in locating buried object in nondestructive environments. Moreover, the Levenberg–Marquardt Fletcher algorithm (LMFA) is applied to determine the medium parameters and buried object location simultaneously. The influences of proposed modulation technique on determining system’s parameters, such as a propagation time, distance, and properties of the medium are analyzed. Calculation results indicate that the proposed UWB-PPM-ATS gives higher accuracy than the conventional one such as UWB-OOK and UWB-PPM in both homogeneous and heterogeneous environments. Furthermore, the LMFA with the proposed UWB-PPM-ATS outperforms the LMFA with the traditional modulation method, especially for unknown propagation environment.

Underground Object Size Approximation using GPR Signal and Image Processing

This paper comprises a step wise method of approximating the size of an underground object using GPR (Ground Penetrating Radar). It involves more than just using predefined filters and techniques. Usage of Trivial method of mathematics to calculate the top surface dimensions of the buried objects is the main purpose of this paper. Problem that is faced that, only the presence of any object can be known using the GPR resource, but not exactly how to derive the size of the object using the same data. This method consists of a dual approach to the problem to make sure that the data that is being given out is accurate. The objectives of this paper are to use the GPR to calculate the top surface dimension of a buried object at a suitable depth according to the frequency. The steps that are incorporated include pre-processing of raw data, determination of ROI (Region of interest) from the pre-processed data, Application of appropriate filters for image processing and estimating surface area and depth of the concealed object. The main reason of this paper is to serve the purpose of detecting what is under the ground in a quick and simpler way using the algorithm proposed