基于三维层状介质模型地震层析成像正演网格研究

地震层析成像技术是研究地层速度结构的一个重要手段，该技术是利用震源到接收点的地震波走时或波形的观测数据，结合建立的数学物理模型来重建地层速度结构。而层析成像正演模拟的精度将直接影响反演出的速度与地层真实速度的拟合度，因此找出一种精度较高的层析成像正演模拟算法是非常重要的。本文针对三维层状介质，通过网格化模型，采用最小走时射线追踪方法展开层析成像正演研究，分别采用三角形网格、矩形网格和六边形网格进行模型参数化，并对比分析各自正演结果的精度，总结出针对三维层状介质模型的最佳网格划分方式。 

The Study of Seismic Tomography Forward Grid Based on 3D Layered Media Model

The seismic tomography technique is an important means to study the velocity structure of the strata, it is the method that combines the seismic wave travel or waveform data of the receiving point with the physical and mathematical model established to reconstruct the velocity structure of the strata. The accuracy of the forward modeling of tomography will directly affect goodness-of-fit of the reverse velocity relative to the true velocity of the stratum. Therefore, it is very important to find a higher precision forward modeling algorithm for tomography. Based on the three-dimensional layered medium, this paper will use the minimum traveltime ray tracing method by gridding model to conduct forward modeling research. In this paper, three grids of triangle, rectangle and hexagon will be used to parameterize the model, and then their forward results accuracy will be compared to summarize the optimal mesh division method for three-dimensional layered medium.