A Channel Phase Error Compensation Method for Space Borne Array SAR Based on Antenna Pattern and Doppler Correlation Coefficient
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摘要: 随着对地观测技术的发展,要求SAR系统能够同时实现高分辨率和宽测绘带,天基阵列多通道SAR结合数字波束形成(DBF)技术为解决该问题提供了很好的思路,但各个通道之间相位误差会很大程度上降低DBF的性能,常规通道误差补偿方法估计精度不足,应用场景受限。针对上述问题,该文提出一种基于方向图和多普勒相关系数的天基阵列SAR通道相位误差补偿方法,不仅利用天线方向图先验信息,还充分利用场景不同多普勒相关性信息,通过最小化天线方向图和多普勒的组合差异,实现对通道之间相位误差的估计。结合RADAR-SAT数据的仿真试验结果验证了该算法的有效性。Abstract: With the development of earth remote sensing technology, SAR system is required to obtain high resolution and wide swath simultaneously, the space borne array SAR combined with Digital Beam Forming (DBF) technology provides a good solution to solve the problem. However, the phase error between channels will degrade the quality of DBF, and the traditional compensation methods suffer from large error or limite application. In this paper, a compensation method based on antenna pattern and Doppler correlation coefficient is proposed, using the antenna pattern and meanwhile utilizing the Doppler correlation coefficient. By minimizing the combined cost function, the phase error between channels are estimated. Simulation results using RADAR-SAT data validate the effectiveness of the proposed method.
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Key words:
- SAR /
- Multi-channel /
- Channel phase error /
- Antenna pattern /
- Doppler correlation coefficient
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表 1 雷达系统参数
参数 数值 雷达工作频率(GHz) 5.3 雷达有效速度(m/s) 150 中心斜距(km) 20 PRF(Hz) 40 带宽(MHz) 50 信噪比(dB) 20 方位向通道数 3 表 2 实际系统的主要参数
参数 数值 工作频率(GHz) 5.3 带宽(MHz) 30 采样率(MHz) 32.3 PRF(Hz) 1256.98 速度(m/s) 7062 通道数 3 相邻通道间的距离(m) 1.9 -
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