Volumetric wavefield recording and wave equation inversion for near‐surface material properties
Volumetric wavefield recording and wave equation inversion for near‐surface material properties
复制标题
近地表材料特性的体积波场记录和波动方程反演
DOI：
10.1190/1.1512751
复制
发表时间：
2002
期刊：
影响因子：
3.3
通讯作者：
J. Robertsson
中科院分区：
文献类型：
--
作者：
A. Curtis;J. Robertsson
地震波场的“体积记录”意味着本地接收器组或阵列近似地包围地球的体积。我们展示了如何体积记录可以用来测量几个空间导数的波场。通过利用全弹性波方程、弹性波场的自由表面条件和类似于合成有限差分建模中使用的Lax-Wendroff校正的导数中心技术，可以反演接收器组正下方近地表的P和S速度的导数估计。所估计的量是波场在任何时间点经历的P分量和S分量的有效速度。因此，速度估计可以随波类型和波长两者而变化。该估计可用于辅助静校正估计，并且准确地是将波场分离成P分量和S分量以及上行分量和下行分量所需的有效速度。
“Volumetric recording” of the seismic wavefield implies that the local receiver group or array approximately encloses a volume of the earth. We show how volumetric recording can be used to measure several spatial derivatives of the wavefield. By making use of the full elastic wave equation, the free surface condition on elastic wavefields, and derivative centering techniques analagous to Lax-Wendroff corrections used in synthetic finite-difference modeling, these derivative estimates can be inverted for P- and S-velocities in the near surface directly beneath the receiver group. The quantities estimated are the effective velocities of the P- and S-components experienced by the wavefield at any point in time. Hence, the velocity estimates may vary with both wave type and wavelength. The estimates may be useful to aid statics estimation and are exactly the effective velocities required for separation of the wavefield into P- and S-, and up- and down-going components.