由于球体的对称性，因此RCS与视线角度无关。

It is independent ofaspect angle because of the spherical symmetry.

频率和方向依赖性的一个简单例子是图2.5中的两个“哑铃”型散射目标。

A simple example offrequency and aspect dependence is the two-scatterer "dumbbell"target of Fig. 2.5.

Figure 2.5. 确定“哑铃”目标相对RCS的几何结构示意图Geometryfor determining relative RCS of a "dumbbell" target.

如果标称距离R远大于两个“哑铃”之间的距离D，则两个散射体与雷达之间的距离约为

If the nominalrange R is much greater than the separation D, the range to the two scatterersis approximately

式（2.48）表明，雷达散射截面是雷达频率和视线角的周期函数。

Equation (2.48) showsthat the RCS is a periodic function of both radar frequency and aspect angle.

两个散射体之间的距离与波长之比越大，散射截面随角度或频率的变化越快。

The larger thescatterer separation in terms of wavelengths, the more rapidly the RCS varieswith angle or frequency.

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

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