ITR: A Novel Framework with Fast Inverse Scattering Algorithms for Future Environmental Sensing

这项研究旨在为多层介质中地球物理地下测量的快速和准确处理开发一种新的框架。目前，只有2-D映射(即地面上的低分辨率图像)可用，这大大限制了目标深度信息。由于计算需求过大，以前针对这些传感器的逆散射算法已被开发出来，但仅适用于均匀背景介质中的目标。这一新的计算框架有望极大地改善环境场地表征的执行方式。研究人员将开发快速而准确的计算算法，用于处理环境场地表征和石油勘探中一些最重要的测量，即电磁感应(EMI)、探地雷达(GPR)、地面地震和三维非均匀多层介质中的井下声波成像测量。这些算法与大规模的计算和可视化平台相结合，形成了一个新的框架，用于当前和未来的环境场地特征，其中可以直接研究三维地下结构，并可以自适应地优化传感器阵列。本文的主要贡献包括：(1)层状介质中基于加速扩展Born/Rytov近似的快速反演方法；(2)多层背景下基于预条件对比度源反演方法的高保真成像算法；(3)基于这些快速逆散射算法的多传感器三维成像与自适应优化框架。这些方法有望获得较高的分辨率，因为它们考虑了导致以前线性反演方法分辨率下降的重要多次散射效应。多层介质中埋入物体的算法的发展代表了反散射法及其在环境场地描述和石油勘探中的应用的重大进展。

Qing Huo LiuDuke UniversityThis research aims to develop a novel framework for rapid and accurate processing ofgeophysical subsurface measurements in multilayer media. At present, only 2-D mappings(i.e., the low-resolution images on the ground surface) are available, greatly limiting the targetdepth information. Due to the excessive computational demand, previous inverse scatteringalgorithms for these sensors have been developed, but only for objects in a homogeneousbackground medium. This new computational framework is expected to dramatically improvethe way environmental site characterization is being performed.The investigator will develop rapid and accurate computational algorithms for the process-ing of some of the arguably most important measurements in environmental site characteriza-tion and oil exploration, namely electromagnetic induction (EMI), ground penetrating radar(GPR), surface seismic, and borehole sonic imaging measurements in 3-D heterogeneous,multilayer media. These algorithms, coupled with large-scale computing and visualizationplatforms, form a novel framework for current and future environmental site characterizationwhere 3-D subsurface structures can be directly investigated, and sensor arrays can be adap-tively optimized. The main contributions of this research are: (1) Rapid inversion methodsbased on accelerated extended Born/Rytov approximations in layered media; (2) High-fidelityimaging algorithms based on preconditioned contrast source inversion methods in a multi-layer background; (3) A 3-D imaging and adaptive optimization framework using these fastinverse scattering algorithms for multi-sensors. These approaches are expected to yield ahigh resolution because they account for the important multiple scattering effects that causethe resolution degradation in previous linear inversion methods. The development of the al-gorithms for objects embedded in multilayer media represents significant advances in inversescattering and its applications in environmental site characterization and oil exploration.