Research On The Technology Of ISAR Imaging For Ballistic Mid-course Targets

Inverse Synthetic Aperture Radar(ISAR)is a microwave imaging system,which can provide an all-weather,day/night capability to generate a high resolution two-demensional radar images of the targets over a long range.ISAR shows a wide application prospect in both civilian and military applications,and has been the research focus of scholars at home and abroad.Developing researches on detection and recognition of Ballistic Missile is of great significance to ballistic missile defense systems.This thesis focuses on ISAR imaging for mid-course targets and the main work is summarized as follows:1.Research on the characteristics of ballistic mid-course targets.The orbital motion and micro-motion is researched.Then,high resolution range profile of ballistic targets is analyzed.Finally,waveforms of signal and signal processing method are selected.2.The principle of ISAR imaging and compensation methods are researched.This paper studies the imaging principle of ISAR turntable and then comparative research of simulation on the main methods for range alignment and phase correction is developed by establishing evaluation system.The performance of each joint time frequency method is analyzed by simulation.3.An ISAR imaging method for ballistic mid-course targets is researched.Firstly,high speed moving target echo model is established and corresponding compensation methods are adopted in the echo processing results.Then,high quality ISAR imaging results of ballistic mid-course target are obtained by selecting appropriate imaging time and screening of imaging results.4.A new improved AMP imaging reconstruction algorithm with real number processing is proposed.Firstly,the algorithm uses real number processing on azimuth dictionary.Then,the characters of the Kronecker Product is used to vectorizing AMP iteration algorithm.This algorithm improves the speed of reconstruction and image reconstruction effect is excellent.Finally,the superiority and efficiency of the algorithm is verified by the simulation.