Research On Imaging Algorithm Of Through-wall Radar Based On Impulse System

Through-wall radar is a non-destructive testing technology that uses electromagnetic waves to penetrate opaque obstacles,and has great value in detecting hidden targets.Based on the impulse system,through-wall radar has a wide bandwidth due to its emitted impulse signal,which can penetrate walls and other media over long distances,perform high-resolution imaging of targets,achieve target positioning,and has significant advantages in through-wall detection.However,research on time-domain imaging algorithms for time-domain signals is relatively scarce,and methods for extracting timedomain target signals are still in the research stage.Based on impulse system throughwall radar imaging,Thesis has researched issues such as clutter suppression,target signal extraction,and positioning,with the following main work:Firstly,in response to the issue of the overlapping of numerous clutter signals with the received time-domain target echo signal,making it difficult to distinguish the reflected target signal,a data preprocessing algorithm for impulse-based through-wall radar was studied.The algorithm includes five steps: Fourier band-pass filtering,system jitter effect correction,sliding mean filtering,distance attenuation gain compensation,and median filtering.Through simulation experiments,it was verified that the preprocessing algorithm can effectively suppress clutter signals and enhance target reflection signals,and a clear hyperbolic region can be observed in the grayscale image of the target echo signal.Secondly,for the problem of target positioning by detecting and extracting target areas,target detection and positioning algorithms were studied.Firstly,a target detection algorithm that combines edge detection and region segmentation was proposed to extract the target area;Secondly,target positioning was studied,and the target curve was locked by the maximum connected domain,and the hyperbolic vertex was determined by hyperbolic fitting.Simulation experiments and results showed that the algorithm can extract target areas and achieve accurate target positioning.Finally,through-wall imaging experiments were conducted and imaging algorithm software was developed.Firstly,an impulse system through-wall radar was set up for imaging experiments,and the experimental results verified the feasibility of the imaging algorithm researched in this paper in practical applications,which can extract timedomain target echo signals for through-wall detection,achieve target imaging and accurate positioning.Secondly,an imaging algorithm software for impulse system through-wall radar was developed based on Matlab,which can easily process data,display imaging effects and positioning results,and was tested with experimental data to verify its feasibility.