Research On Bi-stationary Synthetic Aperture Radar Imaging Of Planar Moving Targets

As an active space-sky microwave detection method,synthetic aperture radar(SAR)has been widely used in environmental protection,natural disaster monitoring,Marine resources detection,fine agriculture,ground mapping and other aspects.After decades of development at the same time,global navigation satellite system(GNSS)signal coverage,revisit cycle is short,the available satellite number,the passive radar system structure is simple,less use restrictions,in global navigation satellite system for the illuminator of passive radar system is very suitable for use in a high-risk imaging monitoring of landslide,glaciers and snow cover SAR remote sensing imaging traditional way return cycle is long,the cost is high,to natural disasters such as landslides,mud-rock flow,avalanche,glaciers provide real-time warning,effective protection of people's life and property security,is more and more attention in recent years.At the same time,after obtaining high-resolution images,more information can be obtained from SAR images,such as whether there is a moving target in the imaging scene,the motion situation of the target,and the size and position of the target,which are also of great significance.This paper mainly introduces the research of moving target imaging of SYNTHETIC aperture radar through the following parts:The first part firstly introduces the application background of SAR imaging,then introduces the research status of ground moving target imaging at home and abroad,as well as the problems and challenges faced by moving target imaging.The second part firstly introduces the theoretical basis of moving target imaging of AIRBORNE SYNTHETIC aperture radar,including the analysis of moving target echo signal and the basic processing method.Secondly,the dual-station SAR moving target imaging system based on navigation satellite is also introduced.The third part studies the moving target imaging of airborne single-station SAR and double-station SAR based on LFM signal.Firstly,several common doppler parameter estimation methods are discussed.Second from the shortage of the traditional method,is proposed based on the improved distance history fitting ground moving target imaging and parameter estimation method,the method using polynomial Fourier transform history matching method,improved the original distance makes up for the traditional method of doppler parameter fitting is not accurate,so as to better focus on imaging of moving targets.Finally,the feasibility of the proposed method is verified by experimental simulation.In the fourth part,the moving target imaging of dual-station SAR based on the navigation satellite system is studied.Firstly,aiming at the narrow band width and poor range resolution of the navigation signal,the range-direction resolution of the navigation signal is improved by the method of frequency band fusion,so as to realize the moving target high-resolution one-dimensional imaging.Secondly,since the stationary target spectrum is unable to image the moving target,the series inversion method is used to derive the moving target spectrum of dual-station SAR based on navigation signal,and two-dimensional imaging of the moving target frequency domain is realized.Finally,the lattice model is simulated to verify the correctness of the method.At the same time,the simulation results of moving target high-resolution fusion imaging under four navigation systems are obtained,and the imaging results under four navigation systems are analyzed and discussed,proving the effectiveness of the method.