高分辨率SAR图像RCS模型的Gamma分布参数估计

Parameter Estimation of Gamma Distribution of RCS Model for High-resolution SAR Images

使用Gamma分布来描述高分辨率合成孔径雷达(SAR)图像的雷达横截面积(RCS),并研究Gamma分布的参数估计问题.基于第二类统计量,并利用斑点的乘性模型,对于三种图像类型(强度图像、幅值图像和多视处理幅值图像),提出了RCS的Gamma分布参数估计的有效方法,参数估计过程只需要斑点和RCS的前两阶对数累积量.RCS的Gamma分布参数估计的Monte Carlo仿真验证了这种方法的有效性,而高分辨率SAR图像RCS的参数估计结果则表明Gamma分布的参数可以用于不同地物的分析与分类.

The Gamma distribution is used to model the radar cross section(RCS) for high-resolution synthetic aperture radar(SAR) images,and its parameters are estimated.Based on the second-kind statistics,together with the multiplicative model of speckle,for three kinds of images(intensity image,amplitude image,and multi-look processing amplitude image),an effective estimator is proposed to estimate the parameters of the Gamma distribution of RCS,and the parameter estimating process only needs the first two log-cumulants of speckle and RCS.Monte Carlo simulations of the parameter estimation of the Gamma distribution of RCS demonstrate the effectiveness of this estimator,and the RCS parameter estimating results of high-resolution SAR image show that the parameters of Gamma distribution can be used for the analysis and classification of various terrains.