Detection of Buried Objects in a Two Layer Medium Illuminated By a Dipole - Abstract

Abstract

The fields scattered by a target buried beneath the ground and observed above the ground are perturbed from their values with no target present. These perturbed fields are evaluated using a Sommerfeld approach for all possible cases of transmitting antenna; i.e., VMD, HMD, VED and HED. For frequencies in the 1 to 30 KHz range, the scattered fields have a quasi-static behavior. The exact expressions for the Sommerfeld integrals are evaluated numerically, and compared with their quasi-static approximations. The scatter from the buried target is generated by the induced electric and magnetic dipole moments from the incident dipole field at the dipole source and propagate to the target. The induced dipole moments then reradiate to an observer. All components of E and H are considered. Several examples are given for various combinations for the transmitting antenna, buried object and layer properties.