改进的RCA偏移速度分析相干谱计算方法

相干谱在剩余曲率偏移速度分析中,是判别速度是否正确以及求取速度更新量的重要工具。然而利用SU相干公式计算的相干谱,对小幅度相干成分和大幅度相干成分缺乏足够的分辨能力,降低了在相干谱上拾取的准确度。基于"使相干值的大小反映信号的能量(幅度)"的思想,采用"幅度归一化"的措施进行了改进,使相干谱中能量团更集中,更能反映主要反射层位,提高了在相干谱中信息拾取的准确度。

Modified Method of Semblance Calculation in RCA Migration Velocity Analysis

Semblance spectrum is the important tool to judge whether the migration velocity is correct or not and obtain the velocity update amount in residual curvature migration velocity analysis.However,if the semblance formula of SU is used to generate semblance spectrum,then the semblance spectrum has no enough resolution ability in respect of strong signals and weak signals,thus the correct degree of picking on the semblance spectrum is decreased.In this paper,modification is made using the method of amplitude normulization,based on the thought that the amount of semblance must be proportional to the energy(amplitude)of signal,the semblace spectrum obtained using modified formula has more concentrated energy and clearer image of major interfaces,thus the correct degree of picking on the semblance spectrum is enhanced.