高斯束成像方法研究进展综述

The review of imaging methods based on gaussian beam

兼顾计算效率和成像精度的高斯束偏移成像方法近年来得到广泛应用.一方面高斯束偏移使用动力学射线追踪,解决了传统射线方法的焦散问题,改善了成像效果;另一方面,高斯束方法选择对成像点有贡献的高斯束叠加来计算波场值,无需费时的两点射线追踪,保证了计算效率.本文主要从高斯束叠后偏移、叠前偏移、起伏地表偏移、高斯束逆时偏移、弹性波偏移、各向异性偏移以及高斯束偏移三类优化策略等方面系统地评述了高斯束成像方法的研究进展,并对高斯束偏移方法下一步发展方向进行了初步展望.

The Gaussian beam migration which keeps high computation efficiency and imaging accuracy simultaneously has been widely used in recent years. On one hand, Gaussian beam method adopts complex-valued dynamic ray-tracing parameters, which solves the problem of caustic region where the traditional ray method fails, improving the imaging result . On the other hand, Gaussian beam migration obtains the final wavefield by stacking the Gaussian beams contributing to imaging points without the time-consuming two-point（source-to-receiver） ray- tracing which can ensure the high calculation efficiency. In this paper, I elaborate the advances in Gaussian beam migration methods systematically , including post-stack migration , pre- stack migration, migration from topography, reverse time migration, elastic wave migration, migration in anisotropic media and three kinds of optimization strategies. What＇s more, some developmental directions about it are discussed primarily.