Identifying weak dielectric objects on conductive surfaces in millimeter-wave imaging

Synthetic Aperture Radar (SAR) Imaging is able to detect not only conducting but also weak dielectric objects. When a dielectric is affixed to a conducting surface, reflection of the dielectric can be difficult to distinguish from the sidelobes from the surface, since they have similar magnitude and range. The ability to distinguish imaging artifacts and target surfaces is necessary to enable automated feature analysis and threat detection of unknown targets. Our new methods varies the imaging bandwidth, which changes the range of the sidelobe position without changing the range of the dielectric peak reflection, which distinguishes the front surface dielectric reflectivity from sidelobe artifacts. Experimental data is used to demonstrate the effectiveness of this approach.