Signal Reconstruction Approach for Multichannel SAR in Azimuth Based on Multiframe Super resolution
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摘要: 方位向多通道技术是星载合成孔径雷达(Synthetic Aperture Radar, SAR)同时实现高分辨率宽测绘带成像的有效手段,对于方位向多通道星载SAR系统,当脉冲重复频率(Pulse Repetition Frequency, PRF)不满足均匀采样条件时方位向信号被非均匀采样,成像前需进行均匀化重建。该文创新性地提出以数字图像处理(Digital Image Processing, DIP)领域多帧超分辨率的思路解决方位向多通道星载SAR非均匀采样信号重建问题,并总结给出了多帧超分辨处理的一般方法。仿真与实测数据实验验证了方法的有效性,且在复杂度性能上具有一定优势。该文第1次建立了方位向多通道星载SAR非均匀采样信号重建与多帧超分辨率问题的联系,为这一信号重建问题的解决提供一种新的思路。Abstract: To achieve high-resolution wide-swath imaging, the use of multichannel techniques in azimuth is effective for spaceborne Synthetic Aperture Radar (SAR). For azimuth multichannel systems, the signal in azimuth is nonuniformly sampled if the uniform sampling condition related to Pulse Repetition Frequency (PRF) is not satisfied, which makes it important to reconstruct the azimuth signal prior to image formation. In this study, to solve the azimuth signal reconstruction problem in multichannel SAR, we propose the innovative use of a multiframe super-resolution method in Digital Image Processing (DIP) and summarize the general multiframe super-resolution process. Our simulation results and real data experiments verify the effectiveness of the proposed method, which demonstrates some advantages in complexity performance. By establishing linkages between the problem of signal reconstruction of nonuniformly sampled signals and the multiframe super-resolution concept, we provide a new approach to this traditional signal reconstruction problem.
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表 1 方位向多通道星载SAR系统参数
Table 1. The parameters for a spaceborne azimuth multichannel system
系统参数 数值 载波波长(m) 0.0311 方位向通道数 4 理想脉冲重复频率(Hz) 1247 载荷飞行速度(m/s) 7483 方位向子孔径间距(m) 3 多普勒带宽(Hz) 4000 -
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