The coastal crustal deformation caused by ocean tidal loading (OTL) varies spatially and temporally, and this spatiotemporal variation in satellite-based interferometric synthetic aperture radar (InSAR) measurements needs to be determined. In this article, we propose a spatiotemporal modeling method to estimate the OTL displacements in InSAR measurements using the kinematic precise point positioning (PPP) solutions of a regional GPS network. We tested the method through an experiment using 25 Sentinel-1B images and long-term observations of 172 GPS reference sites from Southern California. The experimental results suggest that there are significant OTL and solid Earth tide effects in the differential InSAR interferogram, which is greater than 40 mm. We find that the spatial characteristics of OTL variations can be expressed as a high-order polynomial in the two variables of latitude and longitude, and the spatiotemporally modeled PPP tidal estimates of the high-density GPS sites can provide high precision OTL correction for all the pixels in the interferogram. In the last part of the study, we show that the spatial large-scale signals in the differential interferograms of Sentinel-1B data are mainly atmospheric delay, solid Earth tidal, and OTL effect, and demonstrate the importance of the tidal correction in the InSAR measurements.

中文翻译：

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由区域 GPS 网络的运动学 PPP 解决方案确定的 InSAR 测量中的时空海洋潮汐载荷

由海洋潮汐载荷 (OTL) 引起的沿海地壳变形在空间和时间上发生变化，需要确定星基干涉合成孔径雷达 (InSAR) 测量中的这种时空变化。在本文中，我们提出了一种时空建模方法，以使用区域 GPS 网络的运动学精确点定位 (PPP) 解决方案来估计 InSAR 测量中的 OTL 位移。我们通过使用 25 个 Sentinel-1B 图像和来自南加州的 172 个 GPS 参考站点的长期观测结果的实验​​测试了该方法。实验结果表明，大于40 mm的差分InSAR干涉图存在明显的OTL和固体地球潮汐效应。我们发现OTL变化的空间特征可以表示为纬度和经度两个变量的高阶多项式，并且高密度GPS站点的时空建模PPP潮汐估计可以为所有的OTL提供高精度的OTL校正。干涉图中的像素。在研究的最后部分，我们展示了 Sentinel-1B 数据差分干涉图中的空间大尺度信号主要是大气延迟、固体地球潮汐和 OTL 效应，并证明了潮汐校正在 InSAR 中的重要性测量。