摘要: |
针对机载合成孔径雷达(SAR)系统在环境变化比较剧烈或者载机飞行不稳时噪声较大的问题,提出了基于信号时频分析和逆Radon变换的微动目标检测与参数估计方法。首先对振动目标回波信号作DPCA处理;然后对其进行时频分析,提取微动目标的微多普勒特征;最后对时频分析后的信号进行逆Radon变换,估计振动目标参数。干涉信号的微多普勒频率表现为正弦函数的形式,逆Radon变换对正弦信号聚焦但对噪声不聚焦,整个系统所需回波信噪比使用时频分析时低得多。仿真实验验证了算法的有效性。 |
关键词: 合成孔径雷达 微动目标 相位中心偏置天线(DPCA) Radon变换 Hough变换 |
DOI:DOI:10.3969/j.issn.1672-2337.2019.04.003 |
分类号:TN958.94 |
基金项目:国家自然科学基金(No.61871174) |
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An Algorithm for Micro Motion Target Detection and Parameter Estimation for Synthetic Aperture Radar |
LI Changli,HU Lina
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College of Computer and Information,Hohai University,Nanjing 211100,China
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Abstract: |
In view of the problem that airborne SAR system has more noise when the environment is more severe or the aircraft flight is unstable,a method of detection and parameter estimation based on time-frequency analysis and inverse Radon transform is proposed. First,the echo signal of the vibration target is processed by DPCA,and then the time frequency analysis is carried out to extract the micro Doppler characteristics of the moving target. Finally,the inverse Radon transformation of the signal after the time frequency analysis is used to estimate the parameters of the vibration target. The micro Doppler frequency of the interference signal is in the form of sine function. Using the inverse Radon transform to focus on the sinusoidal signal and not focus on the noise,the echo signal to noise ratio of the whole system is much lower when the time frequency analysis is used. The effectiveness of the proposed algorithm is verified by the simulation experiment. |
Key words: synthetic aperture radar(SAR) micro motion target displaced phase center antenna (DPCA) Radon transform Hough transform |