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利用时间-调频率分布特性的复杂运动目标ISAR成像研究

李亚超;苏军海;邢孟道;保铮
  

  1. (西安电子科技大学 雷达信号处理重点实验室,陕西 西安 710071)
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2008-02-20 发布日期:2008-01-20
  • 通讯作者: 李亚超

Research on ISAR imaging of the complexly moving target based on the time-chirp distribution

LI Ya-chao;SU Jun-hai;XING Meng-dao;BAO Zheng
  

  1. (Key Lab. of Radar Signal Processing, Xidian Univ., Xi′an 710071, China)
  • Received:1900-01-01 Revised:1900-01-01 Online:2008-02-20 Published:2008-01-20
  • Contact: LI Ya-chao

摘要: 针对海面舰船目标的复杂运动所引起的调频率的变化并导致方位聚焦质量下降的问题,提出了一种新的基于TC-DechirpClean(时间-调频率平面的解调频Clean搜索方法)的瞬时成像方法,在方位信号的时间-调频率平面内,利用信号散射点调频率变化率的一维搜索方法得到信号的调频率的变化率和调频率值,同时,在补偿高次相位后做FFT变换,根据幅度最大的位置来确定信号的中心频率和幅度信息,重构有用的回波信号,最终对目标进行ISAR成像.实测数据成像结果证明了该方法能有效地解决调频率的变化所造成的方位聚焦质量下降的问题.

关键词: ISAR(逆合成孔径雷达成像), 舰船目标, 调频率, TC-DechirpClean, 方位聚焦

Abstract: The change in chirp rate caused by the complex motion of the ship target deteriorates the azimuth focusing quality. This paper proposes a new imaging method based on TC-DechirpClean(DechirpClean searching method based on the time-chirp distribution), which makes use of the changing rate of scatterers’ chirp to search their chirp rate and change rate of the chirp rate in the time-chirp distribution plane. At the same time, we do FFT after compensating the higher-order phase term to acquire the information about the center frequency and magnitude of these scatterers according to the maximum magnitude criteria. Finally, we can reconstruct the echo signal and obtain an instantaneous ISAR image. The imaging result of real data confirms that this method can greatly improve an unfocused ISAR image caused by the change rate of the chirp rate.

Key words: Inverse Synthetic Aperture Radar(ISAR), ship target, chirp, TC-DechirpClean, azimuth focus

中图分类号: 

  • TN959