Research On The Technique Of Through-the-Wall Radar For Indoor Detection Based On Compressive Sensing

With the increasing demand of the public security department,disaster rescue personnel and rapid response defense forces for obtaining non-line-of-sight information in the urban area,the technology of through wall radar detection has gained extensive attention and research,and has made rapid development in recent years.However,for the signal processing of through wall radar system,large amount of data is usually needed,which will be a challenge for the system and reduce the efficiency of signal processing.With the development of modern digital signal processing technology,the theory of compressive sensing(CS)has been applied to the research of through-the-wall radar imaging(TWRI),which has provided new ideas for solving the mentioned problems,and thus becomes a popular direction in radar signal processing field.In the thesis,the theory and algorithms of compressive sensing radar is discussed and applied to TWRI system.To deal with high complexity of imaging operation and ghost suppression in the background of noise and clutter interference,this paper aims at the design of imaging models and methods for complex target scene.The main contributions are illustrated as follows:1.Interaction multipath in through-the-wall radar imaging based on compressive sensingIn order to mitigate the effect of interaction multipath,considering fast data acquisition and measurement reduction,in this chapter,we made use of the propagation characteristic of interaction multipath to build the sparse model of the target scene and developed a CS-based method,which is referred to as ‘interaction CS’.Intensive evaluation and direct comparison of the imaging results with existing methods are conducted to show that the proposed interaction CS performs better at ghost suppression in the same condition of the signal-to-noise ratio(SNR).2.Compressive sensing based radar imaging for complex non line of sight target sceneIn this work,multipath in radar imaging through the corner and T-like wall of a building is considered.With the propagation characteristic of the corresponding multipath,the sparse model of target scene is built,and then the corresponding CS method is proposed.With the direct comparison to the existing CS-based imaging method,reconstruction results are reported to indicate the better performance of the proposed method on ghost suppression.3.Multiple moving targets indication(M-MTI)for urban sensing using change detection based compressive sensing(CD-CS)Based on the theory of CS,we consider the indication of multiple moving targets in throughthe-wall radar imaging.With the method of change detection,stationary targets and clutter are removed.Then according to the reasonable state of motion,we delete the ghost points and combine the tracing points of each moving target.Comparison with the existing CS-based MTI method shows that,the proposed method,can better estimate the number of moving targets and show the indication of each moving target.