Frequency domain simulation of focused array radar returns from buried mines in clutter

Simulation code was developed to model monostatic or bistatic radar returns from terrain and discrete objects within the radar's field of view, including subsurface scattering due to complex permittivity inhomogeneities and buried objects, using Born approximations. This code is applied to simulation of return from a mine-like dielectric cylinder buried a few inches below the surface. Clutter sources included are: scattering from the rough surface above the mine and subsurface random permittivity inhomogeneities. Simulated images of received power from a subsurface region are obtained with and without the mine and the results will be compared with experimentally-obtained images of the region. Depth resolution of a few inches is obtained by using a focused linear array of 4 transmitters and a linear array of 4 receivers identical to and parallel to the transmitter array. The illuminated subsurface volume is between the two arrays. The detector scans the volume by varying relative delays between array elements such that, at a given time instant t(1) the signals arrive at a point p(1) and returns from p(1) arrive at the 4 receivers with equal delays. Superposition of received signals at time t(1) favors returns from a small volume around p(1). At time t(2) all energy is similarly focussed on a different point p(2). The process continues until the entire volume has been scanned and an image of the region has been generated. Sensitivity to mine dimensions, composition and burial depth and soil parameters is demonstrated.