Effects of a Reflecting Background on the Results of Active MMW SAR Imaging of Concealed Objects

In the last years, several approaches for the detection of concealed threats using millimeter waves at the body of a person have been developed. The utilization of millimeter waves allows the detection of both metallic and nonmetallic objects. One category of setups uses a coherent source for the active illumination of a person in combination with synthetic-aperture-radar processing methods. The general task for all setups is that the objects which have to be detected are placed in front of the human skin, which can be considered as a good reflector for these frequency ranges. The effects of a reflecting background on the images are analyzed in this paper.