Persistent scatter radar interferometry for crustal deformation studies and modeling of volcanic deformation
Persistent scatter radar interferometry for crustal deformation studies and modeling of volcanic deformation
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2006
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通讯作者：
A. Hooper
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作者：
A. Hooper
虽然传统的干涉合成孔径雷达（干涉合成孔径雷达）是测量地壳变形的一种非常有效的技术，但几乎所有干涉图都包括信号去相关且无法测量的大面积区域。因此，迄今为止的大多数干涉合成孔径雷达研究都集中在干旱和植被稀疏的地区。永久散射体干涉合成孔径雷达是一种相对较新的分析技术，它通过识别一系列干涉图中其回波由单个散射体主导的分辨率元素来克服去相关问题。这种技术已被用于分析城市地区，其中角结构产生有效的反射器，占主导地位的背景散射。然而，地球表面的大部分地区都没有人造结构。此外，这种技术需要，先验，变形的近似时间模型，而表征变形的时间模式通常是任何研究的目标之一。我们已经开发了一种新的分析方法，StaMPS，使用干涉相位的空间相关性，找到一个稳定的像素在所有地形，有或没有建筑物的网络。不需要变形速率的时间变化的先验知识。我们将这些像素称为持久散射体（PS）。我们的方法的一个关键组成部分是两个算法的发展展开的三维系列的干涉图。我们观察到随时间变化的变形，使用初始版本的StaMPS，在加州的长谷破火山口获得的数据，在一段时间内，变形率变化显着。PS的推断位移与地面实况比较良好。使用StaMPS的增强版本，我们检测到1997年至2001年期间加拉帕戈斯群岛的Volcán Alcedo破火山口内的稳定通缩期，我们用收缩的椭圆形岩浆建模
While conventional interferometric synthetic aperture radar (InSAR) is a very effective technique for measuring crustal deformation, almost any interferogram includes large areas where the signals decorrelate and no measurement is possible. Consequently, most InSAR studies to date have focused on areas that are dry and sparsely vegetated. A relatively new analysis technique, permanent scatterer InSAR, overcomes the decorrelation problem by identifying resolution elements whose echo is dominated by a single scatterer in a series of interferograms. This technique has been useful for analysis of urban areas, where angular structures produce efficient reflectors that dominate background scattering. However, man-made structures are absent from most of the Earth’s surface. Furthermore, this technique requires, a priori, an approximate temporal model for the deformation, whereas characterizing the temporal pattern of deformation is commonly one of the aims of any study. We have developed a new method of analysis, StaMPS, using spatial correlation of interferogram phase to find a network of stable pixels in all terrains, with or without buildings. Prior knowledge of temporal variations in the deformation rate is not required. We refer to these pixels as persistent scatterers (PS). A key component of our method is the development of two algorithms to unwrap a three-dimensional series of interferograms. We observe temporally-variable deformation, using an initial version of StaMPS, in data acquired over Long Valley caldera in California, for a period when deformation rates varied significantly. The inferred displacements of the PS compare well with ground truth. Using an enhanced version of StaMPS, we detect a period of steady deflation within the Volcán Alcedo caldera in the Galápagos Islands between 1997 and 2001, which we model with a contracting ellipsoidal magma