1.6.4. 雷达应用

1.6.4. Radar Applications

前面的章节引用了一些介绍一般雷达应用的书籍，如成像或脉冲多普勒雷达。

The preceding sections have cited a numberof books addressing general radar applications, such as imaging or pulseDoppler.

在文献中有许多书籍致力于更具体的应用领域。

There are a number of books in theliterature devoted to more specific application areas.

Melvin和Scheer(2014)即将出版的新书将提供对于雷达广泛应用的极好调查和介绍，从而最终完成了整个现代雷达原理系列丛书。

The forthcoming text by Melvin and Scheer(2014) will provide an excellent survey of and introduction to a wide range ofapplications in a single text, and will complete the Principles of Modern Radarseries.

1.6.5. 雷达研究现状

1.6.5. Current Radar Research

当前的雷达研究成果发表在许多科技期刊上。

Current radar research appears in a numberof scientific and technical journals.

在美国发行的最重要刊物包括：IEEETransactions on Aerospace and Electronic Systems, Transactions on Geoscienceand Remote Sensing, Transactions on Signal Processing, Transactions on ImageProcessing。

The most important in theUnited Statesare the Institute of Electricaland Electronics Engineers (IEEE) Transactions on Aerospace and ElectronicSystems, Transactions on Geoscience and Remote Sensing, Transactions on SignalProcessing, and Transactions on Image Processing.

后者中的雷达文献一般限于与SAR处理相关，尤其是三维干涉SAR。

Radar-related material in the latter isgenerally limited to papers related to SAR processing, especiallyinterferometric three-dimensional SAR.

在英国，雷达技术论文通常发表在工程与技术学会IET [前身为电气工程师学会（IEE）] 杂志《IET雷达、声纳与导航》上。

In theUnited Kingdom, radar technologypapers are often published in the Institution of Engineering and Technology(IET) [formerly the Institution of Electrical Engineers (IEE)] journal IETRadar, Sonar, and Navigation.

2. 信号模型

2. Signal Models

2.1. 雷达信号的组成

2.1. Componentsof a Radar Signal

当雷达发射受控的、定义明确的信号时，在接收机输出处测量的信号是几个主要分量的叠加，这些分量都不是设计者可以完全控制的。

While a radar transmits a controlled,well-defined signal, the signal measured at the receiver output in response isthe superposition of several major components, none of them entirely under thecontrol of the designer.

接收机回波信号的主要成分是目标、杂波、噪声，在某些情况下还有干扰。

The major components are the target,clutter, noise, and, in some cases, jamming.

有时这些信号被进一步细分。

These signals are sometimes subdividedfurther.

例如，杂波可以分为地杂波和天气杂波（如雨），而干扰可以分为有源干扰（噪声发射机）和无源干扰（如箔条云）。

For instance, clutter can be separated intoground clutter and weather clutter (such as rain), while jamming can beseparated into active jamming (noise transmitters) and passive jamming (such aschaff clouds).

将接收机输出的合成信号进行处理，目的是提取关于目标的存在及其特征的有用信息，或者形成雷达图像。

Signal processing is applied to thiscomposite signal; the goal is to extract useful information regarding thepresence of targets and their characteristics, or to form a radar image.

噪声和干扰都是无用的信号，它们降低了检测目标并测量其位置和速度的能力。

Noise and jamming are interference signals;they degrade the ability to detect targets and measure their position andvelocity.

在某些情况下，杂波可能是干扰，例如当检测飞机时；或者可能是期望信号，如地面成像雷达。（成像雷达是利用地面杂波成像的）

Clutter may be interference in some cases,such as when detecting aircraft, or may be the desired signal itself, as with aground imaging radar.

信号处理的有效性通过它在各种指标中提供的改进来测量，例如检测概率、信干比(SIR)或角度精度等。

The effectiveness of the signal processingis measured by the improvement it provides in the various figures of merit,such as detection probability, signal-to-interference ratio (SIR), or angleaccuracy.

第一章说明了传统脉冲雷达发射窄带带通信号。

It was shown in Chap. 1 that conventionalpulsed radars transmit narrowband, bandpass signals.

通过将幅度调制限制为开关脉冲，使得传输能量最大化；当需要提高分辨率时，使用相位调制来扩展瞬时带宽。

Transmitted energy is maximized byrestricting amplitude modulation to on-off pulsing; phase modulation is used toexpand the instantaneous bandwidth when needed to improve resolution.

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

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