MIMO-SAR: Opportunities and Pitfalls
MIMO-SAR: Opportunities and Pitfalls
复制标题
DOI：
10.1109/tgrs.2013.2263934
复制
发表时间：
2014-05-01
影响因子：
8.2
通讯作者：
Krieger, Gerhard
中科院分区：
文献类型：
--
作者：
Krieger, Gerhard
本文综述了利用多发射和多接收天线来提高未来合成孔径雷达(SAR)系统性能的先进雷达体系结构。这些先进的体系结构被称为多输入多输出合成孔径雷达(MIMO-SAR)，类似于MIMO通信系统。然而，在选择用于通过多个信道同时传输的适当波形方面出现了相当大的混乱。结果表明，在大多数合成孔径雷达应用中，仅使用正交波形是不能达到预期的性能改善的。作为对这一基本MIMO-SAR挑战的解决方案，引入了一类新的短期移位正交波形。短时移位正交性避免了来自近距离散射体的雷达回波的相互干扰，而来自较远散射体的干扰则通过在仰角接收时的数字波束形成来抑制。通过考虑三维信息立方体中侧视成像雷达的数据采集，可以获得进一步的见解。很明显，建议的波形填充可由多通道接收器单独访问的不同的子空间。为了完备性，还将这种新的短时移位正交波形与最近提出的一对正交频分复用波形进行了比较。结果表明，这两组波形需要通过多通道接收机实现距离-时间-仰角转换的基本原理，才能适用于无干扰的MIMO-SAR成像。
This paper reviews advanced radar architectures that employ multiple transmit and multiple receive antennas to improve the performance of future synthetic aperture radar (SAR) systems. These advanced architectures have been dubbed multiple-input multiple-output SAR (MIMO-SAR) in analogy to MIMO communication systems. Considerable confusion arose, however, with regard to the selection of suitable waveforms for the simultaneous transmission via multiple channels. It is shown that the mere use of orthogonal waveforms is insufficient for the desired performance improvement in view of most SAR applications. As a solution to this fundamental MIMO-SAR challenge, a new class of short-term shift-orthogonal waveforms is introduced. The short-term shift orthogonality avoids mutual interferences from the radar echoes of closely spaced scatterers, while interferences from more distant scatterers are suppressed by digital beamforming on receive in elevation. Further insights can be gained by considering the data acquisition of a side-looking imaging radar in a 3-D information cube. It becomes evident that the suggested waveforms fill different subspaces that can be individually accessed by a multichannel receiver. For completeness, the new class of short-term shift-orthogonal waveforms is also compared to a recently proposed pair of orthogonal frequency-division multiplexing waveforms. It is shown that both sets of waveforms require essentially the same principle of range time to elevation angle conversion via a multichannel receiver in order to be applicable for MIMO-SAR imaging without interference.