Research On The Method Of Though-the-wall Radar Imaging Based On Compressive Sensing

Through-the-wall radar imaging technology uses the performance of electromagnetic waves to penetrate opaque media to realize the targets imaging behind the wall.Through-the-wall radar imaging technology has been widely applied in a large variety of areas such as anti-terrorism reconnaissance,urban operations,disaster rescue etc.It can be widely used not only in military aspects but also widely used in civil aspects.In the process of through-the-wall radar imaging,a large amount of data is generated.Recently,the introduction of compressed sensing can be said to be a revolutionary breakthrough,which can effectively reduce the amount of collected data.Based on the theory of compressed sensing,two imaging methods of through-wall radar are proposed.The main research work of this thesis is as follows:1.The principle of compressed sensing and the three elements of compressed sensing are introduced,and the echo signal model of the through-wall radar is established.Then a two-way delay is obtained in through-the-wall radar system.In deep study of the construction method of dictionary matrix and measurement matrix in the through-wall radar model,which lays a foundation for subsequent research.2.The principle of FDTD method is introduced,then the use method of Gprmax software is described in detail,the scene of through-the-wall radar is established and the time domain data of simulation is obtained by Gprmax simulation software.3.In view of the traditional through-the-wall radar sparse imaging algorithm reconstruction process of memory and computing cost is huge,a efficient sparse imaging reconstruction method is proposed,the Proposed method combines the spectral projected gradient norm(SPGL1)algorithm with the nonuniform fast Fourier(NUFFT)algorithm to realize the image reconstruction.Compared with the traditional sparse imaging algorithm,the proposed method can effectively reduce the computer memory requirements and improve the computational efficiency of imaging reconstruction.4.The traditional high-resolution imaging reconstruction of Diffraction Tomography(DT)requires a large working signal bandwidth and an antenna synthetic aperture,which results in a large amount of system data acquisition and a low measurement speed.In view of the above problems,this method combines the compressed sensing and the diffraction tomography algorithm.The proposed method can guarantee the quality of the target imaging reconstruction result and greatly improve the system measurement speed when the data acquisition in the frequency domain of the system is greatly reduced.