影响高斯束偏移成像质量和效率的主要因素分析  

Analysis of main factors affecting imaging quality and efficiency of Gaussian beam migration

作　　者：张志鹏 孙章庆[1] 韩复兴[1] 王雪秋[1] 刘明忱 高正辉[1] ZHANG Zhipeng;SUN Zhangqing;HAN Fuxing;WANG Xueqiu;LIU Mingchen;GAO Zhenghui(College of Geo-exploration Science and Technology,Jilin University,Changchun 130026,China)

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026

出　　处：《世界地质》2022年第2期349-364,共16页World Geology

基　　金：国家自然科学基金(42074150、41404085)。

摘　　要：高斯束偏移在复杂区域成像潜力巨大,其成像质量和效率受偏移参数和速度模型光滑的影响。基于此,利用理论推导、模型试算进行分析,推导了高斯束偏移的基本原理与模型光滑原理,利用Marmousi模型进行了试算研究。研究结果表明:高斯束偏移成像过程中,浅层成像精度会随最大出射角度增大而提高;射线覆盖完全时,减少傍轴射线数量成像效率提高;高斯窗半宽增加会提高偏移成像精度,但过大则图像失真;随着高斯束半宽减小,成像精度增加,但过小则浅层精度减小;高斯束中心间隔减小则成像精度提高,但成像效率变低;随着速度模型整体光滑次数的增加,成像精度逐渐增加,光滑50次时,偏移成像效果最佳。Gaussian beam migration has great imaging potential in complex areas,and its imaging quality and efficiency are affected by migration parameters and smooth velocity model.Based on this,the authors use theoretical derivation and model trial calculation for analysis.Basic principle and model smoothing principle of Gaussian beam migration are deduced,and trial calculation is carried out by using Marmousi model.Results show that shallow imaging accuracy will improve with increasing maximum exit angle in Gaussian beam migration imaging process.When X-ray coverage is complete,the number of paraxial rays is reduced and imaging efficiency is improved.Increasing the half width of Gaussian window will improve migration imaging accuracy,but if it is too large,image will be distorted.As half width Gaussian beam decreases,imaging accuracy increases,but if it is too small,shallow accuracy decreases.When Gaussian beam center interval is reduced,imaging accuracy is improved,but imaging efficiency becomes lower.With the increase of velocity model overall smoothing times,imaging accuracy gradually increases.When velocity model is smoothed 50 times,migration imaging effect is best.

关 键 词：高斯束偏移 核心参数 模型光滑 成像质量 计算效率 

分 类 号：P631[天文地球—地质矿产勘探]