Direct nonlinear inversion of 1D acoustic media using inverse scatteringsubseries

摘要

A task-specific, multiparameter more than one mechanicalproperty changes across a reflector, direct nonlinear inversionsubseries of the inverse-scattering series is derivedand tested for an acoustic medium in which velocity and densityvary vertically. Task-specific means that terms in the distinctsubseries corresponding to tasks for imaging only andinversion only are identified and separated. Direct meansthere are formulas that solve explicitly for and output thephysical properties, without, e.g., search algorithms, modelmatching and optimization schemes, and proxies that typicallycharacterize indirect methods. Numerical test results withanalytic data indicate that one term beyond linear providesadded value beyond standard linear techniques, and the improvedestimates are valid over a larger range of angles. Thedirect acoustic inversion is nonlinear. It serves as an importantstep for new concepts and methods to guide the muchmore complicated and minimally realistic elastic inverse forexploration seismology target identification purposes.