Through Wall Surveillance Using Ultrawideband Random Noise Radar

Abstract : Recent terrorist activities and law-enforcement situations involving hostage situations underscore the need for effective through-wall detection. Current building interior imaging systems are based on short-pulse waveforms, which require specially designed antennas to subdue unwanted ringing. In addition, periodically transmitted pulses of energy are easily recognizable by the intelligent adversary who may employ appropriate countermeasures to confound detection. A non-coherent polarimetric random noise radar architecture is being developed based on ultrawideband (UWB) technology and software defined radio, which has great promise in its ability to covertly detect obscured targets. The main advantages of the random noise radar lie in two aspects: first, random noise waveform has an ideal thumbtack ambiguity function, i.e., its down range and cross range resolution can be separately controlled, thus providing unambiguous high resolution imaging at any distance; second, random noise waveform is inherently low probability of intercept (LPI) and low probability of detection (LPD), i.e., it is immune from detection, jamming, and interference. Thus, it is an ideal candidate sensor for covert imaging of obscured regions in hostile environments. Other than those advantages, we also suffer some real problems that we lack of the back scattering information in the strong clutter and interference environment and most of the previous through wall studies are based on the research of light cluttered environment. This paper presents the radar system design, simulation study, measurements, and data analysis.