虽然雷达散射截面的指数模型仅在大量散射体的极限下严格精确，但在实际应用中，对于只有10或20个有效散射体的目标来说，它也是一个很好的适用模型。

While the exponentialmodel for RCS is only strictly accurate in the limit of a very large number ofscatterers, in practice it can be a good model for a target having as few as 10or 20 significant scatterers.

Figure 2.10. 图2.9的RCS数据直方图与具有相同均值的指数PDF曲线进行比较Histogram of RCS data of Fig.2.9 and exponential PDF with the same mean.

即使该例子只使用了50个散射体，总的RCS直方图与瑞利/指数分布的拟合也相当好。

Even though only 50scatterers are used, the fit of the total RCS histogram to theRayleigh/exponential distribution is quite good.

当随机分布的散射体也具有从相同的高斯分布中抽取的随机独立RCS时，可以观察到同样的效果，这比固定RCS的情况更为普遍和可信。

This same effect isobserved when the randomly distributed scatterers also have random individualcross sections drawn from the same Gaussian distribution, a somewhat moregeneral and plausible situation than the fixed-RCS case.

一些雷达目标不是由等强度散射体组成的整体，而是由一个或几个占主导地位的散射体组成，这些主导散射体对目标RCS影响较大，其它较小散射体的影响则较小。

Instead of anensemble of equal-strength scatterers, some radar targets are better modeled asconsisting of one or a few dominant scatterers contributing most of the RCS,modified by the contributions of a number of smaller scatterers.

许多类型的PDF被提倡用于对这些目标进行建模。

Many PDFs have beenadvocated and used to model these targets.

——本文译自Mark A. Richards所著的《Fundamentals of Radar Signal Processing（Second edition）》

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