Three-Dimensional Resistivity Imaging System

J. Frounchi and H. Soltani

Microelectronic and Microsensor Research Laboratory, Faculty of Electrical and Computer Engineering, Tabriz University, Tabriz, Iran, Email: jfrounchi@tabrizu.ac.ir

ABSTRACT

A 3-D resistivity imaging system has been designed and simulated which uses a novel electrode arrangement all around the surface. Using this new arrangement, it is possible to employ this system in places where the surface is not easily accessible, such as landmine fields or underneath a building. In the reconstruction procedure, the finite-difference method has been used to model the half-space below the surface. The electrical resistance distribution is obtained from one of the Gauss-Newton or Quasi-Newton techniques. To evaluate our system, several 3-D buried inhomogeneities were modeled. The measurement data is obtained from our forward solver at the start, an initial uniform resistivity value for the earth is assumed and then the simulation is performed. We have obtained some impressive results for the models such as a 3-D T-shaped body and four separate small cubes. In an interesting experiment to emulate a landmine field with different plastic and metal mines, we have modeled four small cubes with different resistivity values. Among these, two resistivity values are higher and two lower than the value of earth’s resistivity. We have been able to detect the right positions of the cubes successfully. The simulation results show that the developed system is not sensitive to noise, since for both high and low damping factors, the reconstructed images are agreeable.

Keywords Electrical resistance tomography, Conductivity measurement, Landmine detection