随机介质模型波场的有效统计特征  

The random medium model and valid statistical characteristics of elastic wave field

作　　者：奚先[1] 姚姚[2] 

机构地区：[1]中国地质大学(武汉)数学与物理学院 [2]中国地质大学(武汉)地球物理与空间信息学院,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2005年第9期109-112,共4页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(4017403440274038).

摘　　要：通过弹性波方程的交错网格有限差分正演,模拟了平面地震波在单层矩形介质模型中的传播及其自激自收时间记录.将理论记录剖面(垂直和水平分量)分割成5个不同的时间区段.在5个不同的时间区段上,分别计算剖面的统计特征:横向中心波数、纵向中心频率和波场能量相对值.这样,对应每一个弹性随机介质模型,均可计算得到15个不同的波场特征量.进一步引入了相对标准差的概念,并由此得到了若干有效波场特征量.通过正演模拟,依次研究了当介质的自相关长度变化、介质的自相关长度和粗糙度因子变化及介质的自相关长度和扰动标准差变化时的波场特征.讨论了介质模型发生变化时,对应的波场特征量的变化特点.Made use of the staggered mesh finite difference simulations of the elastic wave equation, simulated the propagation of the plane seismic wave and relevant zero offset time record in the rectangular single layer medium models. Divided up the theoretic recording sections （vertical and horizontal component） into five different time sectors, and separately calculated the statistical characterizations （Horizontal center frequency, vertical center frequency and relative magnitude of the wave field energy） of the five different time sections. Corresponding every single elastic random medium model, calculated and gained 15 different wave field characteristic quantities. Further more introduced the concept of relative standard deviation, hence gained several valid wave field characteristic quantities. Studied such changing of the wave field features as changing the medium＇s autocorrelation length, the medium＇s autocorrelation length, roughness, the medium＇s autocorrelation length and standard deviations of disturbance. We studied the features of the wave fields when the media＇s features were being changed.

关 键 词：随机介质模型 弹性波模拟 有效波场特征 

分 类 号：P315.63[天文地球—地震学]