A new time series interferometric synthetic aperture radar method is presented based on a strain model. Traditionally, the interferometric phases are optimized based only on a constant set of statistically homogeneous points throughout the observing period, and thus the decorrelated phase cannot be well recovered and possible incoherent (or coherent) phases are (are not) used to optimize the target phase. In the proposed method, a strain model, representing the geophysical relationship of spatially adjacent points' deformations, is employed to optimize the interferometric phases interferogram-by-interferogram. The unwrapped phase time series can be estimated from the wrapped interferograms based on the linear iterative weighted least squares method, which is simple and can effectively suppress the decorrelation noise. Both simulations and analysis of data over The Geysers geothermal field (TG), California are conducted, validating that the proposed method can reduce the decorrelations and simultaneously preserve the deformation signals. The displacement results of TG from 2007–2011 L-band ascending ALOS-1 data and 2015–2020 C-band ascending/descending Sentinel-1 data reveal that (a) the displacement rate of TG is decreasing from 2007–2011 to 2015–2020, and (b) temporally variable displacement signals in addition to steady displacement can be observed from 2015 to 2020 for both the east-west and the vertical components.

中文翻译：

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基于应变模型的 InSAR 时间序列方法及其在加利福尼亚间歇泉地热场中的应用

提出了一种基于应变模型的时间序列干涉合成孔径雷达新方法。传统上，干涉相位仅基于整个观测期间的一组恒定的统计均匀点进行优化，因此解相关相位无法很好地恢复，并且可能的非相干（或相干）相位被（不）用于优化目标相位. 在所提出的方法中，应变模型代表空间相邻点变形的地球物理关系，用于逐个干涉图优化干涉相位。基于线性迭代加权最小二乘法可以从包裹干涉图中估计解包裹相位时间序列，该方法简单且可以有效抑制去相关噪声。对加利福尼亚州间歇泉地热场 (TG) 上的数据进行了模拟和分析，验证了所提出的方法可以减少去相关并同时保留变形信号。TG 2007-2011 L波段上行ALOS-1数据和2015-2020 C波段上行/下行Sentinel-1数据位移结果表明(a) TG位移速率在2007-2011-2015- 2020 年，以及 (b) 除了稳定位移之外，还可以观察到 2015 年至 2020 年的东西向和垂直分量的时间可变位移信号。