Detection of sub-surface objects by electrical impedance tomography

A technique called INSEIT (Imaging Near the Surface by Electrical Impedance Tomography) has been developed for potential applications in the field of medical imaging. The technique allows changes in electrical impedance to be imaged in sub-surface planes below an array of surface electrodes. Although the adaptation of this approach to the task of detecting buried land mines involves some obvious practical difficulties with electrode contact, the method might find application in situations where large electrical impedance contrasts are present. The image reconstruction mathematics used for INSEIT and for general cross-sectional electrical impedance tomography has been shown to be suitable for industrial imaging using capacitive and inductive sensors, so alternative sensing methods based on the same image reconstruction strategy are a possibility. The viability of INSEIT in the practical situation of unknown sub-surface features and an imperfectly flat surface, and the overall performance of the approach in locating buried objects is examined using software simulations and experimental data sets.