基于文氏谱的起伏海面虚反射特征研究  

Study on the Characteristics of Ghosts on Undulating Sea Surface Based on W′spectrum

作　　者：高俊杰 张进[1,2,3] 彭阳阳 董博艺 Gao Junjie;Zhang Jin;Peng Yangyang;Dong Boyi(College of Marine Geoscience,Ocean University of China,Qingdao 266100,China;Laboratory for Marine Mineral Resources,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China;Key Laboratory Sea Floor Resource and Exploration Technique,Ministry of Education,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学海洋地球科学学院,山东青岛266100 [2]青岛海洋科学与技术试点国家实验室海洋矿产资源评价与探测技术功能实验室,山东青岛266237 [3]中国海洋大学海底科学与探测技术教育部重点实验室,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2023年第11期162-170,共9页Periodical of Ocean University of China

基　　金：国家自然科学基金项目(91958206)资助。

摘　　要：海洋地震记录中的虚反射会和反射波发生混叠和干涉,严重影响了海洋地震资料的质量。常规海面水平的条件假设将在海面反射系数计算过程中引入误差。本文引入文圣常提出并改进的文氏海浪谱,采用有效波高、海浪成长系数等各项参数模拟出更符合实际情况的海浪形态,并通过时频分析等方法研究起伏海面虚反射对地震记录的改造作用和起伏海面条件下的虚反射时频谱特征。结果表明:当海面起伏程度较大时,起伏海面的虚反射不仅强烈扭曲了海底一次波反射同相轴,且与一次波发生了强烈的干涉作用,导致成像结果出现很多假同相轴,严重影响了地震资料的质量。随着起伏海面有效波高的增加,地震记录受陷波效应逐渐增强,虚反射能量逐渐增加,主频幅值逐渐减小。当海面起伏变化时,随着偏移距的增加,陷波点幅值变化丰富,主频幅值逐渐减小,且向高频方向移动。随着震源或检波器沉放深度逐渐增加,有效波虚反射的能量强度逐渐增加,频带变窄,陷波改造作用强烈,主频幅值逐渐减小。The ghosts in marine seismic records often interfere with the reflected waves,which seriously lowers the quality of seismic data.In traditional seismic data processing,the sea surface is often assumed to be flat,which will lead to errors in the estimation of sea surface reflection coefficients and ghost delay.This paper therefore introduces the Wen’s wave spectrum to simulate the actual wave pattern with effective wave height,wave growth coefficient,and other parameters.In addition,this paper also investigates the effect of ghost reflection on seismic records and explores the characteristics of ghost reflection in time-frequency spectrum.When the sea surface fluctuates greatly,the ghosts not only distort the reflection events of the seafloor,but also strongly interfere with the reflections,resulting in many false events in the seismic profile.With the increase of the effective wave height of the undulating sea surface,the notch effects of seismic records intensify gradually,the ghost energy increases and the amplitude of the main frequency component decreases gradually.With the increase of the offset,the amplitude of the trap point varies dramatically,and the amplitude at the main frequency decreases gradually.With the increase of the sinking depth of the source or geophones,the ghost energy increases gradually,the frequency band narrows,the frequency spectrum is strongly reformed by the notch,and the amplitude of it decreases gradually.

关 键 词：虚反射 起伏海面 文氏谱 时频分析 

分 类 号：P631.4[天文地球—地质矿产勘探]