| 摘要: |
| 方位多通道SAR（Synthetic Aperture Radar）系统采用数字波束形成技术(Digital Beam-Forming, DBF)，能够克服最小天线面积的限制，有效地解决了高分辨率与大测绘带之间的矛盾，实现了高分辨率宽测绘带对地观测，多发多收模式是方位多通道SAR未来的发展方向。对于方位多通道SAR系统，通道间的幅相误差对系统成像性能有很大影响，必须对其进行标定。利用子空间投影算法，提出了一种基于地面发射机和接收机的定标方法。其利用地面布设的发射机和接收机，分别估计出接收通道间的幅相误差和发射通道间的幅相误差，实现收发通道相位误差分离，从而估计出多发多收模式下各回波包含的幅相误差值。基于发射机和接收机估计方法的精度均得到了仿真验证。最后通过点目标仿真实验，对提出方法的有效性进行了仿真验证。实验表明，该方法通过布设地面发射机和接收机即可对多发多收模式下通道间的幅相误差进行标定，实现成像的校正。 |
| 关键词: 方位多通道SAR 多发多收 幅相误差 定标方法 |
| DOI：10.3969/j.issn.1672-2337.2018.02.007 |
| 分类号:TN958 |
| 基金项目:国家高分对地观测重大专项（No.GFZX0403220401） |
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| Amplitude-Phase Error Calibration Method for Multiple Transmit Multiple Receive SAR System |
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LI Yukun， HONG Jun， MING Feng
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1. Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China;2. National Key Laboratory of Science and Technology on Microwave Imaging, Beijing 100190, China;3. University of Chinese Academy of Sciences, Beijing 100049, China
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| Abstract: |
| Incorporated with digital beam-forming (DBF) techniques, the azimuth multi-channel spaceborne SAR system is able to overcome the limitation of minimum antenna constraint and resolve the contradiction between high resolution and wide swath, so that it can yield high resolution and wide swath (HRWS) images. For this reason, the multiple transmit multiple receive mode become a development direction of azimuth multi-channel SAR. For an azimuth multi-channel spaceborne SAR system, the amplitude-phase errors between channels have a negative effect on the quality of imaging, so we must calibrate those errors. Utilizing signal subspace comparison algorithm, this paper puts forward a method of amplitude-phase error estimation based on transmitter and receiver on the ground. This method can estimate amplitude-phase errors among transmit channels and receive channels respectively, so that it can estimate all kinds of amplitude-phase errors of echoes. Finally, the effectiveness and precision of the proposed algorithm are validated by simulation. The experiment shows that, this method can calibrate the amplitude-phase errors respectively among transmit channels and receive channels in multiple transmit multiple receive mode through laying transmitter and receiver on the ground. |
| Key words: azimuth multi-channel spaceborne SAR system multiple transmit multiple receive amplitude-phase error calibration method |
