本文提出了多视平均幅值合成孔径雷达(SAR)图像的拖尾Rayleigh先验模型的参数估计方法。首先,本文通过对数变换把SAR图像的乘性模型变为加性形式;其次,本文使用负数阶矩理论,推导出真实图像的对数变换的期望和方差;最后,本文基于斑点的对数变换的高斯近似,获得了斑点的对数变换的期望和方差。所提估计方法具有解析的表达式,便于实现。MonteCarlo仿真和真实SAR图像的参数估计实验表明,所提方法可以有效的从多视平均幅值SAR图像估计出拖尾Rayleigh先验模型的参数。
A parameter estimator of the heavy-tailed Rayleigh prior model was proposed for the multi-look averaged amplitude Synthetic Aperture Radar (SAR) image. First, the multiplicative model of SAR image was changed into the additive one according to the logarithmic transformation. Then, the expectation and variance of the log-transformed original image were derived using the theory of negative-order moments. Lastly, the expectation and variance of the log-transformed speckle were obtained based on the Gaussian approximation of the log-transformed speckle. The proposed estimator is easy to be implemented in the form of analytical expressions. Parameter estimation experiments on Monte Carlo simulations and real SAR images demonstrate that the proposed estimator can efficiently estimate the parameters of the heavy-tailed Rayleigh prior model from the multi-look averaged amplitude SAR image.