孙建国,,
孟祥羽,
徐杨杨,
刘明忱,
商耀达
吉林大学地球探测科学与技术学院, 长春 130026
基金项目: 国家自然科学基金项目（41974135）资助
详细信息
作者简介: 魏脯力, 男, 1993年生, 吉林大学地球探测与信息技术专业在读博士, 主要从事地震波正演及偏移成像研究.E-mail:wei_pl@126.com
通讯作者: 孙建国, 男, 1956年生, 教授, 博士生导师, 目前主要从事地下波动理论与成像技术、计算地球物理、科学计算方法与技术、海洋反射地震资料处理、地下天线理论以及岩石物理等方面的教学和研究工作.E-mail:sun_jg@jlu.edu.cn
中图分类号: P631收稿日期:2019-11-27
修回日期:2020-08-24
上线日期:2020-10-05
Influence of smoothing velocity on reflected seismic signal
WEI PuLi,SUN JianGuo,,
MENG XiangYu,
XU YangYang,
LIU MingChen,
SHANG YaoDa
College of GeoExploration Science and Technology, Jilin University, Changchun 130026, China
More Information
Corresponding author: SUN JianGuo,E-mail:sun_jg@jlu.edu.cn
MSC: P631--> Received Date: 27 November 2019
Revised Date: 24 August 2020
Available Online: 05 October 2020
摘要
摘要:光滑处理使得单界面成为非均匀薄层，界面反射转变为层反射.为了探讨光滑处理的影响，以平面波作为入射波场，首先利用过渡层反射系数推导了反射信号的理论公式，然后就非均匀薄层下反射系数的计算问题，给出了具体的实现算法，并通过与经典Epstein过渡层反射系数解析结果的对比说明了算法的精度.最后在单界面及其被光滑后界面的对比分析中，得出了几点重要结论：随着光滑次数的增加，反射信号的到时基本保持不变，而反射信号的主频与能量呈减少趋势，其中信号能量在低光滑次数的衰减速率明显大于高光滑次数.
关键词: 平面波/
反射系数/
光滑/
软界面/
信号能量
Abstract:The usual velocity interface can be converted into an inhomogeneous thin layer by smoothing, making the layer reflection different from original interface reflection obviously. In order to analyze the influence such smoothing on reflected wave signal quantitatively, we take an incident plane wave into account and derive the formula of the reflected signal that is expressed by the reflection coefficient of the corresponding inhomogeneous thin layer. An iterative solution to reflection coefficient equation is used to obtain its reflection coefficient, and we make sure the accuracy of this iteration algorithm in comparison with analytical results in the classical Epstein transition layer. Comparison of final received signals reflected by the usual interface and that by its smoothed inhomogeneous thin layer shows that the arrival time of reflected wave signal remains unchanged while its dominant frequency and energy decrease as the number of smoothing increases. In particular, the signal energy with low smoothing number decreases more faster than that with high smoothing number.
Key words:Plane wave/
Reflection coefficient/
Smoothing/
Soft interface/
Signal energy
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