【读书2】【2014】基于MATLAB的雷达信号处理基础(第二版)——雷达散射截面的统计描述(2)
图2.6为D = 10λ 和 R = 10,000D情况下哑铃目标RCS变化的精确计算。
An exact calculationof the variation in RCS of the dumbbell target is plotted in Fig. 2.6 for thecase D = 10λ and R = 10,000D.
Figure 2.6. D = 10λ 和 R = 10,000D情况下哑铃目标的相对RCS数据 Relative radar cross section ofthe “dumbbell” target of Fig. 2.5 when D = 10λ and R = 10,000D
上图的数据已经经过归一化处理,因此最大值为0dB。
The plot has beennormalized so that the maximum value corresponds to 0 dB.
注意,当两个散射体的回波通过不同长度的路径传播时,多波瓣结构会导致它们的回波在有益和破坏干扰之间变化移动。
Notice the multilobedstructure as the varying path lengths traversed by the echoes from the twoscatterers cause their echoes to shift between constructive and destructiveinterference.
还应注意,90°和270°视线角处的最大值(两种“端射”情况)范围是最宽的,而0°和180°的两种“侧视”情况下的最大值范围是最窄的。
Also note that themaxima at aspect angles of 90° and 270° (the two “end fire” cases)are the broadest, while the maxima at the two “broadside” cases of 0°and 180° are the narrowest.
图2.7以更传统的极坐标格式绘制了与图2.6相同的数据。
Figure 2.7 plots thesame data in a more traditional polar format.
Figure 2.7. 图2.6数据的极坐标示意图Polarplot of the data of Fig. 2.6.
利用式(2.47)的推广形式,可以将具有多个散射体的目标的相对RCS计算表示为θ和λ的函数。
The relative RCS of atarget with multiple scatterers can be computed as a function of θ and λ usinga generalization of Eq. (2.47).
假设N个散射体中的第i个对应RCS为σi,距雷达的距离为Ri(θ)。
Suppose there are Nscatterers, each with its own RCS σi , located at ranges Ri(θ)from the radar.
注意距离Ri随着视线角θ的变化而变化。
Note that the rangesRi vary with aspect angle θ.
回波的复电压将处于一定的比例常数范围内。
The complex voltageof the echo will be, to within a proportionality constant.
——本文译自Mark A. Richards所著的《Fundamentals of Radar Signal Processing(Second edition)》
更多精彩文章请关注微信号: