飞机上和宇宙飞行器上使用的合成孔径雷达(SAR)成象系统,通常是按直线飞行路经来进行设计的。为了把这样的线性合成孔径聚焦到有最佳的分辨率,对于由运动引起的与上述线性飞行路经的偏差,采用机械和电子的方法进行精确的控制。本文叙述了以旋转天线为基础的合成孔径雷达的原理。就安装在直升飞机上的短程雷达成象系统而言,我们可以从中发现一些有趣的新的应用。因为成象仅用到由旋转体引起的多卜勘频谱,所以该系统无需前向速度。最初的设计研究表明,一个毫米波频率(35千兆赫/94千兆赫)的系统看来有可能与专用直升飞机的要求和约束相一致。由于这些合成孔径不再是直线式的,而是圆环段,所以图象形成过程需要一个极座标格式的处理结构。如果进行实时处理的话,将提供全视域观测的能力(360°)。本文给出了一个最初设计实例的性能参数。 Synthetic aperture radar (SAR) imaging systems used on aircraft and in space vehicles are usually designed in a straight-line flight path. In order to focus such a linear synthetic aperture to the best possible resolution, precise control of mechanical and electrical methods is used for deviations from the linear flight path caused by the movement. This article describes the principle of a synthetic aperture radar based on a rotating antenna. For short-range radar imaging systems installed on helicopters, we can find some interesting new applications. The system does not require forward velocity because the imaging uses only the multi-bin spectrum caused by the rotator. Initial design studies showed that a system of millimeter-wave frequencies (35 gigahertz / 94 gigahertz) appears likely to be consistent with the requirements and constraints of a dedicated helicopter. Since these synthetic apertures are no longer linear but rather ring segments, the image formation process requires a polar coordinate format processing structure. Full-field observation capability (360 °) will be provided if real-time processing is performed. This article gives the performance parameters of an initial design example.