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

Duke University, Durham NC

Investigators

Abstract

Qing Huo Liu Duke University This research aims to develop a novel framework for rapid and accurate processing of geophysical 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 target depth information. Due to the excessive computational demand, previous inverse scattering algorithms for these sensors have been developed, but only for objects in a homogeneous background medium. This new computational framework is expected to dramatically improve the 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 visualization platforms, form a novel framework for current and future environmental site characterization where 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 methods based on accelerated extended Born/Rytov approximations in layered media; (2) High-fidelity imaging algorithms based on preconditioned contrast source inversion methods in a multi- layer background; (3) A 3-D imaging and adaptive optimization framework using these fast inverse scattering algorithms for multi-sensors. These approaches are expected to yield a high resolution because they account for the important multiple scattering effects that cause the resolution degradation in previous linear inversion methods. The development of the al- gorithms for objects embedded in multilayer media represents significant advances in inverse scattering and its applications in environmental site characterization and oil exploration.