基于模型参数化的地震波走时与射线路径计算

Computation of Seismic Traveltimes and Raypath Based on Model Parameterization

模型的建立与描述是地震资料分析与处理的基础,合理的模型参数化方式对于地震正反演的各个方面都有很好的效果,其中射线追踪在正演模拟、层析成像及偏移等研究领域中都占有很重要的地位。本文针对地震波走时与射线路径计算,设计了一种将离散模型连续化的最小二乘模型参数化方法,分别对速度模型和走时模型进行模型参数化,然后进行梯度速度模型验算及误差分析。计算结果表明,该模型参数化方法使走时计算精度从10-2提高到10-3,使射线路径的计算精度提高了14.33%。最后通过经典Marmousi模型和Sigsbee 2A模型实例验证,充分证明了该模型参数化方法的有效性及普遍适用性。

The establishment and description of the model is the basis of seismic data analysis and processing,and the reasonable model parameterization method has achieved good results for all aspects of seismic forward and inversion.Ray tracing plays an important role in the fields of forward modeling,tomography,and migration.The authors studied the ray tracing method,designed a model of least squares parametric method,parameterized the model of velocity and travel time respectively,and then tested it by using the velocity gradient model and error analysis.The results show that the model parameterization improves the precision of travel time calculation and the tracking ray path.The validity and applicability of the model parameterization method are proved by the example of the classical Marmousi model and the Sigsbee2A model.