Extending Persistent Scatterer InSAR to Heavily Vegetated Regions Using Information Theoretic Analysis

地壳变形测量通过让我们看到我们不能直接观察到的过程，对我们对构造、地震、火山活动和滑坡的理解做出了巨大贡献。它们通常用于约束活动断层的地下几何形状，推断同震滑动的空间分布，以及研究火山爆发前弹性地壳对岩浆侵入的响应。这些数据是记录余震、粘弹性和孔弹性调整以及无震地震等地震过程的主要手段。对膨胀穹隆和地壳拉伸的精确测量有助于预测火山活动。类似的数据在量化活动滑坡的运动学方面起着重要的作用。利用现代信息理论，研究人员已经推广了InSAR的持续散射技术，这是一种视觉大地测量技术，允许在大范围内绘制详细的运动地图，并暴露复杂的变形模式。他们的技术有助于在自然地形中找到稳定的点，这些点可以用作质量较差的干涉图中的基点网络。这将有助于将InSAR分析扩展到植被茂密的地区。调查人员正在将他们的新技术应用于圣安德烈亚斯断层和海沃德断层的旧金山湾段。他们的观测将有助于跟踪更多地区的地震周期，并可能补充火山的大地测量，以及提高InSAR在许多其他应用中的能力。该项目的更广泛影响包括增加更多信息来评估各种地形的自然灾害，如地震、火山和山体滑坡，培训研究生使用这些方法，并向感兴趣的研究人员免费提供软件和算法。

Crustal deformation measurements contribute enormously to our understanding of tectonics, earthquakes, volcanism, and landslides by permitting us to see processes we cannot observe directly. They are used routinely to constrain the subsurface geometry of active faults, to infer the spatial distribution of coseismic slip, and to study the response of the elastic crust to magma intrusion preceding volcanic eruptions. These data are the primary means for recording aseismic processes such as afterslip, viscoelastic and poroelastic adjustments and silent earthquakes. Accurate measurements of inflationary doming and stretching of the crust help in the forecasting of volcanic activity. Similar data play an important role in quantifying the kinematics of active landslides.Using modern information theory, the investigators have generalized persistent scatterer techniques for InSAR, a visual geodetic technique that permits detailed mapping of motion over wide areas and exposes complex deformation patterns. Their technique helps to find stable points in natural terrain which can be used as a network of fiducial points in otherwise poor-quality interferograms. This will help extend InSAR analysis to heavily vegitated areas. The investigators are applying their new techniques to the San Francisco Bay segment of the San Andreas Fault and Hayward Fault. Their obervations will help follow the earthquake cycle in more areas and may compliment geodetic measurement of volcanoes, as well as improve InSAR capabilities in many other applications. The Broader Impacts of the project include adding more information to assess natural hazards, like earthquakes, volcanoes and landslides, in a variety of terrains, training of graduate students in these methods and making software and algorithms freely available to interested researchers.