摘要
针对合成孔径雷达(synthetic aperture radar,SAR)侧视观测模式及天线方向图引起的SAR图像辐射差异严重影响SAR图像的广泛应用问题,根据经验模态分解(empirical mode decomposition,EMD)技术的自适应、自驱动和多尺度等特性,提出了基于EMD技术的SAR图像自适应辐射均衡方法。该方法利用EMD技术获取SAR图像距离向的多阶本征模函数,自适应地确定包含辐射误差的低频信息,并将其优化可获得辐射误差趋势信息和补偿因子,从而均衡SAR图像。将该方法应用到已知误差趋势的仿真数据以及多组机载SAR真实数据,结果表明该方法能够有效地自适应补偿SAR图像的辐射差异,提高了SAR图像的可视化效果和解译能力。
To solve the problem that the application of synthetic aperture radar(SAR)image is seriously affected by its radiation differences which result from SAR side-looking mode and the antenna pattern,based on empirical mode decomposition(EMD)technique of adaptive,self-driven and multi-scale features,this paper proposes the SAR image adaptive radiation balance method based on the EMD technique.Firstly,by using the technology of EMD,it gains the intrinsic mode function(IMF)of SAR image's range directions.Next,it adaptively determines the low frequency containing background radiation error.Then,by smoothing the trend information it obtains compensation factor.Finally,it realizes the balance of the SAR image.With a known radiation difference of simulation data and multiple sets of airborne SAR real data to do the experiment.The results show that the method can efficiently and adaptively make up for the radiation difference of the SAR image,and improve the visualization and interpretation skills of the SAR image.
引文
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