Imaging Techniques For Ultra-Wideband Through-Wall Detecting Radar

Ultra-Wideband Through-wall Detecting Radar (UWB-TWDR) can detect the targets and its various features that obscured by obstacles, it have important applications in urban street fighting, the fight against terrorism, police riot control, disaster relief and other fields. Imaging techniques of UWB-TWDR significantly improved the differentiability and applicability, can obtained more abundant information than the location techniques.The focus in this thesis is the echo signal processing method and the imaging method for UWB-TWDR. The adaptive interference canceling suppressed direct wave method is proposed based on the average interference canceling method, and demonstrated the efficacy of this method that can adapt to changing by the wall surface is undulate. According to the characteristics of radio frequency interference (RFI) for UWB-TWDR, The RFI suppressed algorithms of MSE-based and wavelet transform-based are proposed, and the suppressed performance of MSE-based median filter algorithm is optimal. To enhance the recognition capability of the radar system, this thesis proposed the 3-D coherent imaging method and achieved 3-D imaging for the targets behind the wall. Demonstrated the efficacy of the method and analyzed the impact for the incorrect estimates of the different wall constant. Finally, proposed the UWB-TWDR 3-D non-coherent imaging method based on the 2-D non-coherent imaging.