Research On Imaging Efficiency And Error Constraint Of High-speed Bistatic Forward-looking SAR

High-speed bistatic forward-looking synthetic aperture radar(HBFSAR)is a new field combines high-dynamic platform and bistatic forward-looking imaging.It could realize two-dimensional high-resolution imaging in forward looking area.Therefore,HBFSAR has vital application values in military field for tracking sensitive targets and terminal guidance.However,the platform has higher speed and acceleration due to its high-dynamic characteristic,and the acceleration effect should be considered in comparison with the traditional bistatic SAR.At the same time,the platform motion error is more severe,and the synchronization precision is higher because of the high-dynamic characteristic.In this thesis,we will study the imaging efficiency and error constraint of high-speed platform bistatic forward-looking synthetic aperture radar.The main contents are as following:(1)Study on system features of bistatic forward-looking configuration and put forward a geometric model which is suitable for high-dynamic condition.What is more,we discuss the two-dimensional space variance and the shift of Doppler centroid and Doppler rate are studied for different azimuth position.At last,we analyze range and azimuth resolution based on the gradient theory.The method is applicable to any configuration.(2)This thesis presents a method for the trajectory boundary of high-speed bistatic forward-looking synthetic aperture radar system due to the fact that the imaging result is restricted by the receiver and transmitter.This method considers the fact of resolution and the angle of equidistant line and equal-Doppler line,which makes the design of trajectory boundary more accurate.In addition,the method can be modified according to the imaging requirements,and it is not necessary to iterate in the trajectory acquisition process,which reduces the amount of calculation greatly.Finally,the feasibility and correctness of the method are verified by simulation.(3)We discuss the motion error model under high dynamic conditions.We analyzed the effects of fixed velocity error,linear velocity error and low frequency sinusoidal motion error on imaging and the effects are simulated by software.(4)Discussed the time synchronization,frequency synchronization and spatial synchronization error of high dynamic bistatic forward-looking SAR.Built the error models of the three synchronization errors.At the same time,we discuss the effects of different types of synchronization errors on imaging by simulation.