平方慢度解析射线追踪层析成像

地震层析成像能提供较高的分辨而成为当今地震勘探领域的一个新热点.以动力学特征为基础的射线追踪代表了地震层析成像的一个方向.解析射线追踪是将介质离散为一系列的单元,并设各单元的速度分布是一定的.本文将介质网格离散化,每单元的平方慢度为线性分布,基于射线扰动理论,由汉密尔顿函数法进行解析射线追踪和傍轴射线追踪.利用平方慢度梯度为常数的分布函数进行解析射线追踪其表达式结构简单而又精确,在程序实现上是很方便的.通过几种二维介质模型进行正演计算,说明其运算速度是很快的.并与最小走时射线追踪法比较,其精确度也是很高的.通过程序的改进这种平方慢度的解析射线追踪将有效地应用于实际.

SEISMIC TOMOGRAPHY OF GRADIENT OF SQUARE SLOWNESS ANAYTICAL RAY TRACING

The seismic tomography has a become a new technique in the seismic exploration because of providing a high resolution. The ray-tracing basd on dynamic character is on behalf of a direction of the seismic tomography. In the analytical ray-tracing the media are divided into a series of the cells in which the velocity distributions are accurately given. We propose a technique for analytical situation of ray-tracing . The complex heterogeneous are divided into the cells in which the square of the slowness has a simper liner distribution. The analytical ray-tracing and paraxial ray-tracing are programmed analytically by a Hamiltonian formalism on the basis of diffracted theory. Programming analytical ray-tracing by making use of square slowness gradient distribution formalism, its expression constitution is simple and accurate, so it is also easy to complete program. It shows that the computing velocity is quick by forward calculation of several two dimensional medium. Its accuracy is higher than the shortest travertine ray-tracing. It indicates that the analytical ray-tracing method is efficient in application through program improved.