反射地震的自动空间校正方法

Automatic spatial correction methods in reflection seismology

中国地质大学物探系, 武汉430074

Department of applied Geophysics, China University of Geosciences, Wuhan 430074

本文根据不同类型的地震t_o数据, 采用以下两种计算机自动空间校正的方法：(1)对离散的数据点, 首先在平面上进行t_o数据网格化, 再求出格点处的真深度值, 然后勾画等值线；(2)对沿已知t_o等值线上拾取的点, 首先求出每个点的t_o时间梯度值, 再沿负梯度方向寻找特征点G, G点处界面的真深度等于空校点到界面的法线深度, 最后用直线或样条曲线把同一t_o值所对应的特征点连接起来, 就可获取一条等深线。在具体处理过程中, 有时需引入辅助点, 再线性内插求出梯度值。本方法避免了繁琐的手工劳动, 处理灵活, 速度快, 空校精度高。

In this paper, two automatic spatial corrcction methods are introduccd in accordance with different types of scismic to data. (1) For discrcte data, first, form a planar grid of to value, next,calculate the true depth at eaeh grid point, after that, plot thc contours. (2) Given that to contours are known, for each point of particular to contour, first, calculate its time gradient, then find the point G in thc reverse direction of time gradient, whose true depth of the reflector equals the normal depth between the corrected point and thc reflector, and finally connect the G's, which are corresponding to the same to contour, with line scgments or spine curvcs. The Curves such generated are isobathes. In practice, auxiliary points are somctimes needed to determine gradient by means of lincar interpolation. The methods presented here bypass the tedious manaul calculations and have the advantages of flexibility, speedy computation, and high accuracy.