Acoustic Reverse-time Migration using Optimal Staggered-grid Finite-difference Operator Based on Least Squares

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• 作者：Hongyong Yan ; Lei Yang ; Hong Liu
• 关键词：Key wordsmigration ; difference operator ; image quality ; least squares
• 刊名：Acta Geophysica
• 出版年：2015
• 出版时间：June 2015
• 年：2015
• 卷：63
• 期：3
• 页码：715-734
• 全文大小：1729KB
• 刊物主题：Geophysics/Geodesy; Structural Geology; Geotechnical Engineering & Applied Earth Sciences;
• 出版者：Springer International Publishing
• ISSN：1895-7455
• 卷排序：63

文摘

Reverse-time migration (RTM) directly solves the two-way wave equation for wavefield propagation; therefore, how to solve the wave equation accurately and quickly is very important for RTM. The conventional staggered-grid finite-difference (SFD) operators are usually based on the Taylor-series expansion theory. If they are used to solve wave equation on a larger frequency content, a strong dispersion will occur, which directly affects the seismic image quality. In this paper, we propose an optimal SFD operator based on least squares to solve acoustic wave equation for prestack RTM, and obtain a new antidispersion RTM algorithm that can use short spatial difference operators. The synthetic and real data tests demonstrate that the least squares SFD (LSSFD) operator can mitigate the numerical dispersion, and the acoustic RTM using the LSSFD operator can effectively improve image quality comparing with that using the Taylor-series expansion SFD (TESFD) operator. Moreover, the LSSFD method can adopt a shorter spatial difference operator to reduce the computing cost.