Research On Motion Compensation And Imaging Algorithm Of Missile Borne SAR

As the precision guided weapons becomes important in the modern war,the missile borne SAR imaging technology has become the focus of national defense industry.However,due to the great difference between the missile and the aircraft,the traditional SAR algorithm is difficult to be used directly in the missile borne SAR.Therefore,this paper studies the missile borne SAR algorithms based on the positive side-looking and the large squint mode,the results of the research are as follows.Firstly,On the basis of discussing the basic principle of SAR imaging,in view of the complex characteristics of the moving state of the missile borne SAR platform,the side-looking imaging geometric configuration of the missile borne SAR is established,and the difference between it and the ordinary SAR imaging model is analyzed.Then the expression of the slant distance of radar to scene and the expression of the echo signal are given.The reversion of the series method is applied to deduce the expression of two-dimensional spectrum of missile borne SAR echo signal.On this basis,different compensation functions are constructed,and a side-looking imaging algorithm and a large scene CS imaging algorithm suitable for missile borne SAR are proposed.In view of the large squint angle which results in the serious defocus of SAR imaging,the SPECAN algorithm is studied.Finally,the effectiveness of the algorithms are verified by simulation.Secondly,The motion error and compensation method of missile borne SAR model are studied.The complex flight state of a missile during its imaging process will have a great impact on the quality of SAR imaging.In this paper,the echo signal is processed by estimating the Doppler center frequency and the Doppler FM slope to realize the motion compensation,and the validity of the compensation algorithm is verified by the imaging of the measured data.On the basis of missile borne SAR imaging,In SAR 3D imaging algorithm is also studied in this paper.According to the specific process of interferometric SAR imaging,including image registration,flat-earth effect removal,noise filtering and phase unwrapping,the effective algorithm of each step is given.Based on these algorithms,the point target and the measured data of ETNA are simulated.Finally,the situation of the In SAR imaging of the sparse signal model is also studied.Finally,In this paper,the C++ project is written on the basis of the research results of the relevant algorithms and a series of function modules in the project aregiven.Finally,the effectiveness of the project is verified by the simulation results of the point target and the measured data.