Liu Jian, Zhang Huili, Wang Lihua, Wang Zhiyong
Nanjing Center, China Geological Survey, Nanjing, Jiangsu Province, China.
Spatial Information Technology Application Department, Changiiang River Scientific Research Institute, Wuhan, Hubei Province, China.
PLoS One. 2024 Aug 8;19(8):e0308636. doi: 10.1371/journal.pone.0308636. eCollection 2024.
Aiming at the characteristics that the signal noise ratio (SNR) gradually decreases from the near to far range of the swath, an adaptive phase filtering algorithm based on Goldstein filtering and combined with multiple quality-guided graphs was proposed. Firstly, the components used to determine the filtering parameters were obtained through residue density, pseudo-coherence coefficient and pseudo-SNR, the three quality-guided graphs. Then, the filter parameters were calculated by weighting the three components. Finally, the size of filtering window was determined according to the account of residues, and the interferometric phase noise was removed in frequency domain. Simulated data, TSX/TDX data and airborne interferometric imaging radar altimeter data were used to verify the performance of the new algorithm. Compared with the results of Goldstein filtering and its improved algorithms, the results showed that the proposed algorithm can effectively filter out phase noise while maintaining the edge characteristics of interferometric fringe. The section of filtering result can well match with the section of simulated pure interfeometric phase. Moreover, the algorithm proposed in this paper can effectively remove the noise in the interferogram of TSX/TDX sea ice data, and the residues' filtering rate was above 86%, which can effectively remove the phase residues of the sea ice surface while maintaining the characteristics of the sea ice edge. Experimental results showed that the new algorithm provides an effective phase noise filtering method for imaging radar altimeter data processing.
针对测绘带内信号噪声比（SNR）从近到远范围逐渐降低的特点，提出了一种基于Goldstein滤波并结合多个质量引导图的自适应相位滤波算法。首先，通过残差密度、伪相干系数和伪SNR这三个质量引导图获取用于确定滤波参数的分量。然后，对这三个分量进行加权计算滤波参数。最后，根据残差数量确定滤波窗口大小，并在频域中去除干涉相位噪声。利用模拟数据、TSX/TDX数据和机载干涉成像雷达高度计数据对新算法的性能进行验证。与Goldstein滤波及其改进算法的结果相比，结果表明所提算法能够在保持干涉条纹边缘特征的同时有效滤除相位噪声。滤波结果剖面与模拟纯干涉相位剖面能够很好地匹配。此外，本文提出的算法能够有效去除TSX/TDX海冰数据干涉图中的噪声，残差滤波率在86%以上，能够在保持海冰边缘特征的同时有效去除海冰表面的相位残差。实验结果表明，新算法为成像雷达高度计数据处理提供了一种有效的相位噪声滤波方法。
