Experimental HF radar for sub-surface sensing

This paper describes our experimental approach for 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 sensor. Data analysis requires the use of Synthetic Aperture Radar (SAR) processing to focus the image. The experiments and initial results are based upon the use of surface contact antennas as part of a larger effort with an ultimate goal of collecting data via airborne sensors. One immediate goal of this in-house 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. Key words: underground structures, below ground imaging, ground penetrating radar, HF rada