一种各向同性稳定杂波包络分布的近似模型

在雷达系统中，CFAR处理的对象通常为杂波的包络。杂波包络的统计分布对于设计CFAR处理器至关重要，包络的统计分布通常由杂波的幅度概率密度函数（APDF）表征。解析形式的APDF是实现系统性能分析的关键。雷达杂波具有典型的非高斯性，适合采用α稳定分布模型来描述，然而该分布的概率密度函数不存在解析的表达，相应的APDF也无解析的表达。针对α（1,2]各向同性稳定杂波，采用线性混合模型，给出了一种各向同性稳定杂波APDF近似的解析模型，该模型具有形式简洁、计算简便的优点。基于对数矩性质，对各向同性杂波包络序列，提出了一种简便的稳定杂波参数的估计方法。 

An Approximation to Envelop Distribution of Isotropic Stable Clutter

In radar systems, it is feasible that amplitude probability density function (APDF) is analytically known and tractable for CFAR processing and detection. Unfortunately, there is no closed-form expression for the probability density function of envelop of stable clutter. To overcome such challenge, we develop a closed-form model to approximate actual APDF of isotropic stable clutter for α（1,2]. Proposed model fits actual APDF well while keeps concise, and hence, tractable form. Simulation results illustrate that proposed model is a valid approximation to actual APDF of stable clutter. Via Logarithm moment, a new approach to estimate parameters of clutter from series of isotropic stable clutter envelop is further proposed.