22 July 1994 Factors governing selection of operating frequency for subsurface-imaging synthetic-aperture radar
Author Affiliations +
A subsurface-imaging synthetic-aperture radar (SISAR) has potential for application in areas as diverse as non- proliferation programs for nuclear weapons to environmental monitoring. However, subsurface imaging is complicated by propagation loss in the soil and surface-clutter response. Both the loss and surface-clutter response depend on the operating frequency. This paper examines several factors which provide a basis for determining optimum frequencies and frequency ranges which will allow synthetic-aperture imaging of buried targets. No distinction can be made between objects at different heights when viewed with a conventional imaging radar (which uses a 1D synthetic aperture), and the return from a buried object must compete with the return from the surface clutter. Thus, the signal-to-clutter ratio is an appropriate measure of performance for a SISAR. A parameter-based modeling approach is used to model the compelx dielectric constant of the soil from measured data obtained from the literature. Theoretical random-surface scattering models, based on statistical solutions to Maxwell's equations, are used to model the clutter. These models are combined to estimate the signal-to-clutter ratio for canonical targets buried in several soil configurations. Results indicate that the HF spectrum (3-30 MHz), although it could be used to detect certain targets under some conditions, has limited practical value for use with SISAR, while the upper VHF through UHF spectrum ($AP100 MHz - 1 GHz) shows the most promise for a general purpose SISAR system. Recommendations are included for additional research.
© (1994) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Billy C. Brock, Billy C. Brock, Ward E. Patitz, Ward E. Patitz, "Factors governing selection of operating frequency for subsurface-imaging synthetic-aperture radar", Proc. SPIE 2217, Aerial Surveillance Sensing Including Obscured and Underground Object Detection, (22 July 1994); doi: 10.1117/12.179937; https://doi.org/10.1117/12.179937

Back to Top