Target resolution enhancement in UWB radar for security system

Detection of body-worn hidden weapons requires improved target resolution. Human being with attached hidden weapon represents multi-target system where weapon as a target in question is masked by human body response. Before application of identification methods it is necessary to resolve composing responses belonging to human and target of interest. Both true time-domain (TD) and frequency domain (FD) representation of responses suffer an ambiguity of signal interpretation when targets are placed close to each other with masking effect. Method of multiple target resolution is suggested based on both TD and FD analysis of equalized signal. UWB short pulse is utilized as an interrogating signal and time-domain responses are measured. Results of TD measurements are presented and signal equalizing calibration procedure is described. Signal processing is based on adaptive filtering algorithms to provide equalization by a reference channel in order to remove any RF system distortion of the received signal. It is shown that combined utilization of calibrated and equalized signals in terms of both power spectrum density (PSD) and TD impulse response enables multi target resolution.