Sub-surface object sensing with multi-frequency microwave radiometry

Previous modeling studies have indicated that a multi-frequency radiometer could prove advantageous for shallow, sub-surface object sensing due to the oscillatory patterns in brightness temperature versus frequency that would be observed in the presence of a sub-surface object. Initial experimental results are reported in this paper from a multi-frequency radiometer system operating in the 2.1-6.5 GHz band. Measured brightnesses with sub-surface metallic and styrofoam targets are provided that demonstrate the predicted oscillatory behavior.