This article investigates the presence of a new interferometric signal in multilooked synthetic aperture radar (SAR) interferograms that cannot be attributed to the atmospheric or Earth-surface topography changes. The observed signal is short-lived and decays with the temporal baseline; however, it is distinct from the stochastic noise attributed to temporal decorrelation. The presence of such a fading signal introduces a systematic phase component, particularly in short temporal baseline interferograms. If unattended, it biases the estimation of Earth surface deformation from SAR time series. Here, the contribution of the mentioned phase component is quantitatively assessed. The biasing impact on the deformation-signal retrieval is further evaluated. A quality measure is introduced to allow the prediction of the associated error with the fading signals. Moreover, a practical solution for the mitigation of this physical signal is discussed; special attention is paid to the efficient processing of Big Data from modern SAR missions such as Sentinel-1 and NISAR. Adopting the proposed solution, the deformation bias is shown to decrease significantly. Based on these analyses, we put forward our recommendations for efficient and accurate deformation-signal retrieval from large stacks of multilooked interferograms.

中文翻译：

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SAR干涉测量表面变形的系统偏差研究

本文研究了多视合成孔径雷达 (SAR) 干涉图中新干涉信号的存在，该信号不能归因于大气或地表地形变化。观察到的信号是短暂的，随时间基线衰减；然而，它不同于归因于时间去相关的随机噪声。这种衰落信号的存在引入了系统相位分量，特别是在短时间基线干涉图中。如果无人看管，它会根据 SAR 时间序列对地表变形的估计产生偏差。在这里，对提到的相分量的贡献进行了定量评估。进一步评估了对变形信号检索的偏置影响。引入了质量度量以允许预测与衰落信号相关的错误。此外，还讨论了减轻这种物理信号的实用解决方案；特别注意有效处理来自现代 SAR 任务（如 Sentinel-1 和 NISAR）的大数据。采用所提出的解决方案，变形偏差显示出显着降低。基于这些分析，我们提出了从大量多视干涉图进行有效和准确的变形信号检索的建议。变形偏差显着降低。基于这些分析，我们提出了从大量多视干涉图进行有效和准确的变形信号检索的建议。变形偏差显着降低。基于这些分析，我们提出了从大量多视干涉图进行有效和准确的变形信号检索的建议。