| 摘要: |
| 相位解缠是干涉合成孔径雷达信号处理的关键步骤之一，而噪声和数据欠采样等因素的存在使得这一过程非常困难。网络流算法有效抑制了噪声对高相干区域的影响并且能够克服“孤岛现象”，能够把误差传递限制在一个很小的范围内，但是由于噪声的影响，解缠结果还是会有明显的“尖峰毛刺”现象。针对网络流的特点，结合残差点的思想和曲面拟合法提出了一种新的相位解缠算法。新的算法根据相关度从初步解缠结果中找出噪声点，然后运用最小曲面拟合法重构值代替噪声点的数值，最后沿着已保存的积分路径更正所有包含此误差点的路径的结果。重复迭代直至将所有的噪声点全部消除，最终的解缠结果是由多个最小曲面多次构成。仿真实验和实测数据实验都证明新算法可以有效改善解缠结果中的“尖峰毛刺”现象的同时，可以进一步抑制解缠误差的传递，提高解缠精度。 |
| 关键词: 干涉测量 相位解缠 网络流法 最小曲面拟合 |
| DOI：10.3969/j.issn.1672-2337.2018.05.012 |
| 分类号:TN958 |
| 基金项目:国家自然科学基金（No.61561010）； 广西自然科学基金（No.2017GXNSFAA198089）； 广西科学研究与技术开发计划项目； 广西教育厅科研立项项目（No.KY2015LX096） |
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| Hybrid Phase Unwrapping Algorithm Combining Surface-Fitting and Network Flow |
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JIANG Liubing， LIU Yongji， CHE Li
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1.Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing, Guilin 541004， China;2.School of Computer and Information Security，Guilin University of Electronic Technology， Guilin 541004, China;3.School of Information and Communication，Guilin University of Electronic Technology, Guilin 541004, China
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| Abstract: |
| Phase unwrapping is a key step of signal processing in interferometric synthetic aperture radar.The unwrapped results can be strongly influenced by noise and under-sampling.The network flow algorithm can effectively suppress noise in high coherence region，overcome the side effect of 'island' phenomenon，and confine the error transfer to a very small range.However，spikes and glitches still exist in the results.Combining with the concept of residues，the surface fitting method and the network flow algorithm，this paper proposes a new phase unwrapping algorithm.The new algorithm locates the noise points based on the correlation degree of neighborhood pixels，reconstructs the noise value using minimum surface fitting，and finally corrects the integral results along the integration path.Repeat the iteration until all the noise points are eliminated and many minimum surfaces are fitted repeatedly to form the final unwrapping result.Results obtained from the simulated data and the measured data show that the proposed method not only achieves better solution with an acceptable time consumption，but also weakens the spikes and glitches as well as restrains the error transfer of the unwrapping process， increasing the precision of phase unwrapping. |
| Key words: interferometry phase unwrapping network flow minimum surface fitting |
