A comparison of experimental and modeled results of an active millimeter wave inverse synthetic aperture radar system used to perform standoff detection of person-borne improvised explosive devices

Abstract

With the recent rise in casualties resulting from person-borne improvised explosive devices (PBIEDs) or ”suicide bombers,” there is an urgent need for standoff detection of such threats. An optimum system that fulfills the requirements of standoff detection must be portable, low cost, and have a high probability of detection with low probability of false alarm at a distance of at least 20 meters. Currently there are a variety of modalities being researched to perform standoff detection of PBIED's including: backscatter X-ray imaging, infrared imaging, optical detection, terahertz imaging, video analytics, and millimeter-wave (MMW) imaging. MMW imaging at 94 GHz is a very good modality for performing standoff detection of PBIEDs. MMWs can propagate through the atmosphere and clothing with very little attenuation, while at the same time do not cause damage to human skin tissue. A mono-static linear frequency modulated continuous wave (LFMCW) circular inverse synthetic aperture radar (ISAR) system has been developed and tested. A model of such a system using a two dimensional full wave analysis based on the finite difference method in the frequency domain has been developed and compared with results of the experimental system. Using a two dimensional matched filtering technique in the frequency domain, simulated images have been used as a means of performing target detection and classification. The imaging results of both simulated and experimentally obtained data is presented in this paper. Initial results using the 2D matched filtering target classification technique will also be presented.