层速度的tomography反演

讨论了地震层析成像中的几个重要问题。采用Ｂ－样条的线性组合表示展速度模型，用Ｂ－样条的光滑性和紧支柱性质，在保持模型光滑的条件下，把积分几何的反问题转化为求解大型、稀疏线性方程组问题。提出了二步射线追踪算法，解决了现有方法的不收敛或遗漏射线问题。讨论了图像在投影方向上的频谱和图像频谱的关系，阐明了投影的角度和投影的疏密对图像重建的影响，文中给出仿真及实际地震资料的实验结果。

Tomographic inversion of interval velocities

The paper presents some new ideas in model construction, ray tracing algorithm, and in problems arising from image reconstruction with incomplete data. The interval velocities model is represented by linear combination of B-splines, the inversion of integral geometry is thus turned into solving a large set of sparse linear equations with the smoothness of the model still guaranteed. The paper proposes a two-step ray tracing method which is an accurate and efficient procedure for determination of the raypaths in complex geological model. A relation between the spectrum of image and the spectrum of the degenerated image in projective direction and several signal processing procedures for dealing with the ill-posed problems arising from image reconstruction with incomplete data are included. The experimental results of the interval velocities inversion with synthetic and real data are also provided.