Abstract Conventional synthetic aperture radar (SAR) interferometry (InSAR) has been successfully used to precisely measure surface deformation in the line-of-sight (LOS) direction, while multiple-aperture SAR interferometry (MAI) has provided precise surface deformation in the along-track (AT) direction. Integration of the InSAR and MAI methods enables precise measurement of the two-dimensional (2D) deformation from an interferometric pair; recently, the integration of ascending and descending pairs has allowed the observation of precise three-dimensional (3D) deformation. Precise 3D deformation measurement has been applied to better understand geological events such as earthquakes and volcanic eruptions. The surface deformation related to the 2016 Kumamoto earthquake was large and complex near the fault line; hence, precise 3D deformation retrieval had not yet been attempted. The objectives of this study were to (1) perform a feasibility test of precise 3D deformation retrieval in large and complex deformation areas though the integration of offset-based unwrapped and improved multiple-aperture SAR interferograms and (2) observe the 3D deformation field related to the 2016 Kumamoto earthquake, even near the fault lines. Two ascending pairs and one descending the Advanced Land Observing Satellite-2 (ALOS2) the Phased Array-type L-band Synthetic Aperture Radar-2 (PALSAR2) pair were used for the 3D deformation retrieval. Eleven in situ Global Positioning System (GPS) measurements were used to validate the 3D deformation measurement accuracy. The achieved accuracy was approximately 2.96, 3.75, and 2.86 cm in the east, north, and up directions, respectively. The results show the feasibility of precise 3D deformation measured through the integration of the improved methods, even in a case of large and complex deformation.

中文翻译：

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通过基于偏移量的展开和改进的多孔径 SAR 干涉测量的集成，在大而复杂的变形区域中进行精确的三维变形检索：在 2016 年熊本地震中的应用

摘要 传统合成孔径雷达 (SAR) 干涉测量 (InSAR) 已成功用于精确测量视线 (LOS) 方向的表面变形，而多孔径 SAR 干涉测量 (MAI) 已成功提供沿视线 (LOS) 方向的精确表面变形。 -track (AT) 方向。InSAR 和 MAI 方法的集成能够从干涉测量对中精确测量二维 (2D) 变形；最近，上升和下降对的整合允许观察精确的三维 (3D) 变形。精确的 3D 变形测量已应用于更好地了解地震和火山爆发等地质事件。与2016年熊本地震相关的地表变形在断层线附近大而复杂；因此，尚未尝试精确的 3D 变形检索。本研究的目的是 (1) 通过集成基于偏移的展开和改进的多孔径 SAR 干涉图，在大型复杂变形区域中执行精确 3D 变形检索的可行性测试，以及 (2) 观察相关的 3D 变形场到 2016 年熊本地震，甚至在断层线附近。两个上升对和一个下降高级陆地观测卫星 2 (ALOS2) 相控阵型 L 波段合成孔径雷达 2 (PALSAR2) 对用于 3D 变形反演。11 次原位全球定位系统 (GPS) 测量用于验证 3D 变形测量精度。东、北、上方向的精度分别约为 2.96、3.75 和 2.86 厘米。