Near field focusing algorithm for high frequency ground penetration imaging radar

Ground penetrating radar has been successfully used for imaging stratigraphic structures. The goal of our ground penetrating radar program is to provide a capability for strategic subsurface target detection for military applications. This paper describes an experimental approach to high frequency (HF) radar sub-surface profiling, and the results obtained from signal and data processing for deep tunnel detection. Ongoing experiments employ a bistatic radar system designed to detect buried objects located in the near field of the HF sensor. Data analysis requires the use of synthetic aperture radar (SAR) processing to focus the image. Currently, experiments are conducted using surface contact antennas as part of a larger effort with an ultimate goal of collecting data via airborne sensors. The immediate goal of this effort is to determine the resolution achievable at depths commensurate with buried structures of strategic importance. This paper also examines the trade-off between frequency and propagation in an attempt to effect the best resolution possible.