本文首先对各种不同类型的共成像点道集进行了概述,然后从定义、主要用途、提取方法、剩余曲率关系以及共成像点道集与速度误差间的联系等方面进行具体的比较分析,给出了定量和定性结果,从而对各种共成像点道集的特征有了更深入的认识,可作为进行有效偏移速度分析时的参考依据.最后又基于模型分别提取了偏移距域共成像点道集(ODCIGs)、射线参数域共成像点道集(PhCIGs)和角度域共成像点道集(ADCIGs).通过模型试算,比较了几种道集的优缺点,对比指出ADCIGs是最适合做偏移速度分析及振幅分析的共成像点道集.通过分析比较有利于更全面具体的理解各种共成像点道集的性质,并为后续的工作打下一定基础.
In this paper, we summarize various common-image gathers (CIGs) of the different domains. Then we compare and analyze the gathers specifically from these aspects: definition, main purposes, extraction method, residual curvature relations and the relationship between gathers and velocity errors. Then, we obtain the quantitative and qualitative results. A better and deeper understanding to features of different CIGs can be used as an effective reference and foundation for migration velocity analysis. And finally we extract offset-domain common-image gathers (ODCIGs), ray-parameter domain common-image gathers (PhCIGs) and angle-domain common-image gathers (ADCIGs) in the numerical tests. Through the model tests, we compare with the advantages and disadvantages of several CIGs. Moreover the comparison show that ADCIGs is the most suitable CIGs for migration velocity and amplitude analyses. According to the analysis and comparison, it is helpful to understand the characteristics of various imaging gathers more comprehensively, that is a useful basis for subsequent work.