摘要
近年来,利用逆合成孔径雷达(ISAR)对非合作机动目标进行成像观测,在战场侦测、空地资源管控等诸多领域得到了广泛的应用。传统的机动目标ISAR成像算法在估计目标调频率时,往往存在运算量较大与传递误差明显的问题,从而导致成像质量下降。为解决上述问题并获取分辨率良好的ISAR图像,本文提出了一种基于分数阶傅里叶变换(FRFT)的快速ISAR成像算法。首先分析提取了目标调频率与两组FRFT变换角之间的几何关系式,之后设计相应的运动参数估计算法,即可快速、独立并且准确地估计得到目标调频率,从而有效避免传递误差对参数估计精度的影响,进而改善成像质量。除此之外,所提算法仅利用两组FRFT变换角进行辅助估计调频率,避免了传统搜索带来的巨大运算量,因此能够显著降低算法复杂度。最后利用实测数据验证了所提算法的有效性。
Inverse synthetic aperture radar(ISAR)imaging of uncooperative maneuvering targets has found wide application in many fields,such as battlefield reconnaissance and resource management.Traditional ISAR imaging algorithms usually suffer from heavy computation burden and considerable propagation error when estimating the chirp rate term of maneuvering targets,resulting in poor imaging quality.To solve these problems and obtain high resolution ISAR images,a fast ISAR imaging algorithm based on fractional Fourier transform(FRFT)is proposed.The geometrical relationship between target chirp rate and two sets of FRFT transform angles is analyzed and determined at first,and then a motion parameter estimation algorithm is developed.In this way,the target chirp rate can be estimated rapidly,independently,and accurately,avoiding the effect of the propagation error on parameter estimation and improving the imaging quality.Moreover,because only two sets of transform angles are used during the chirp rate estimation,the computation load is reduced significantly and the algorithm complexity is also reduced.Test results show the effectiveness of the proposed algorithm.
作者
张俊
董锦
宋文青
相飞
梁晓宇
ZHANG Jun;DONG Jin;SONG Wenqing;XIANG Fei;LIANG Xiaoyu(Xi'an Electronic Engineering Research Institute, Xi'an 710100)
出处
《火控雷达技术》
2020年第3期1-6,共6页
Fire Control Radar Technology
基金
装备发展领域基金(61406190101)
上海航天科技创新基金(SAST2017-070)。
关键词
逆合成孔径雷达
机动目标
运动参数估计
分数阶傅里叶变换
inverse synthetic aperture radar(ISAR)
maneuvering target
motion parameter estimation
fractional Fourier transform
作者简介
张俊(1991-),男,博士研究生,研究方向为雷达成像技术。
