Time Reversal Technology And The Application In Radar

Time reversal(TR)technology is derived from the promotion of phase conjugate mirror(PCM)in the field of photology.Introduced in the field of electromagnetic,it combines the electromagnetic wave transmission principle and array signal processing technology.Time reversal technology has the characteristic of temporal focusing properties,in a multipath scattering and complex environment,it can adaptively focusing on target location,and in the form of wave inversion reconstruction.Time reversal technology makes full use of the information of the physical process of electromagnetic wave transmission,and can obtain a higher resolution than the conventional array aperture to improve the radar resolution.This paper mainly studies the application of time reversal technique in the radar scenarios.This paper firstly analyze the basic principle of time reversal technique.From the point of view of signal transmission,the temporal and spatial focusing characteristics of time reversal technique are proved by theoretical derivation.The basic array signal model is constructed by using the time reversal mirror(TRM)as an example,and the simulation results of time reversal characteristics of time reversal technique are realized on the software platform.Secondly,the time reversal technique is applied to the multipath suppression method.The basic model of specular reflection multipath transmission is established,and the principle of multi-path problem and the harm to the target detection are analyzed.For the characteristic of the typical linear frequency modulation(LFM)pulse signal,derive the process of multipath suppression method inversion,verified through the computer simulation.Then,reserch the algorithm of decomposition of the reversal operator(DORT)and time reversal multiple signal classification(TR-MUSIC)that based on the theory of subspace.First of all,from the perspective of the signal transmission process,the definition of time reversal operator(TRO)is given.In combination with the definition of subspace and related theorem,signal subspace(SS)and the noise subspace(NS)is defined.Thus it can derive the definition of the imaging expression of DORT algorithm and TR-MUSIC algorithm.Finally,study the application in the radar imaging field and analyze the property of a selective focus imaging algorithm.In this paper,a TR-CS-MUSIC algorithm is proposed to realize the time inversion focus on the far field target by combining the time inversion technique with the CS-MUSIC algorithm in the sparse signal model.In this paper,we test the adaptability and stability of the time inversion technique to the target detection and the feasibility of the multi-path effect suppression in the complex multipath scattering environment by validating the temporal and spatial focusing characteristics of the time inversion technique.The simulation analysis of DORT algorithm and TR-MUSIC algorithm shows the advantages and disadvantages of the two methods.The basic idea of time inversion operator decomposition is substituted into the array signal model,which verifies the feasibility of time inversion technology in radar signal processing and target imaging.The TR-CS-MUSIC algorithm combined with the compression perceptual theory can accurately estimate the direction of the signal in the sparse signal model with few snapshots.