Research On Airborne Dual-channel SAR-GMTI Ground Moving Target Detection Techniques

Airborne SAR-GMTI has a strong practical application value.This paper focuses on the airborne dual-channel SAR-GMTI ground moving target detection technology.The topic selection has important practical value and certain theoretical significance.The main research work of this paper can be summarized as follows:1.SAR imaging principle and echo characteristics of moving target are studied.The principle of BP algorithm for static imaging is introduced emphasically.And the theoretical basis of bearing position migration,defocusing and distance movement of the moving target image are analyzed in detail.2.In this paper,a SAR-GMTI channel preprocessing method is improved from the perspective of signal processing,including channel registration and channel equalization.Firstly,in the data Doppler domain,the received echoes of the two channels are "aligned",that is,channel registration,by means of de-interfering phase slope.Aiming at the problem of interferometric fringe tilting,the channel registration is achieved by compensating the phase of each distance point.Secondly,amplitude-phase two-step equalization method is used to correct the amplitude and phase errors between channels,so that they have approximately the same transmission characteristics,namely channe l equalization.Simulation and experimental data processing verify the effectiveness of the proposed method.3.The method of moving target detection based on DPCA-ATI joint processing is studied,and the radial velocity of moving target is estimated by us ing the phase and amplitude information of moving target respectively.Aiming at the disadvantage of DPCA and ATI when they are used alone,a new method of moving target detection based on DPCA and ATI is proposed.This paper uses the amplitude and phase information of moving target to realize the non-fuzzy estimation of radial velocity of moving target,and achieves the refocusing of moving target.Through simulation and experimental data processing,good dynamic target detection and refocusing effects are obtained.