TI介质角度域高斯束逆时偏移方法

Angle-domain reverse time migration with Gaussian beams for TI media

高斯束逆时偏移兼具高斯束偏移灵活、高效和逆时偏移高精度的优势,具有面向目标成像的能力。本文将基于相速度的各向异性射线追踪算法引入高斯束逆时偏移中,并结合高斯束计算时的传播角度信息,实现了一种更为高效的TI介质角度域高斯束逆时偏移方法。模型试算表明:同传统基于弹性参数的各向异性算法相比,在保证成像精度的前提下,本文方法具有更高的计算效率,同时提取的角度域共成像点道集(Angle Domain Common Imaging Gather,ADCIG)不仅能够为后续偏移速度分析提供支撑,而且可以用于分角度叠加成像,压制成像噪声、提高成像质量。

The reverse time migration with Gaussian beams combines the high efficiency and flexibility of Gaussian beam migration and the high precision of reverse time migration,which can be used for target-oriented imaging.In this paper,an anisotropic ray tracing algorithm based on phase velocity is introduced into the reverse time migration with Gaussian beams,and combined with the propagation angle information of Gaussian beam calculation,a more efficient angle-domain Gaussian beams reverse time migration method for TI media is realized.According to our model trial,compared with the conventional anisotropic algorithm based on elastic parameters,the proposed method has higher computational efficiency and extracted angle-domain common imaging gathers(ADCIGs)can not only provide support for subsequent migration velocity analysis,but also be used for stack imaging to suppress imaging noise and improve image quality.