地震勘探反演方法 正演延拓 假设炮点在地层最底层，向上延拓-Forward seismic inversion method assuming continuation shot in the bottom of the formation, upward continuation

用于进行周期延拓相关方面的计算，可以作为参考程序-Continuation related aspects of the calculation used for cycle, can be used as a reference program.

位场向下延拓的泰勒级数方法，利用拉普拉斯方程的特点，计算空间域水平二阶差分来替代垂直方向上的二阶差分-Potential field downward continuation of Taylor series method, the advantage of the characteristics of Laplace equation, a second order differential spatial domain levels instead of second order diff