转换点坐标的模拟计算研究

转换波上下行波传播路径具有非对称性,转换点相对于共中心点的距离随着纵横波速度比、界面深度以及炮检距等因素的变化而变化,因此转换波速度分析和叠加的关键问题之一就是如何抽取共转换点道集。采用简洁有效的方法来计算转换点坐标是做好共转换点选排的前提,本文在单个均匀层情况下,对已有的转换点坐标计算公式进行了模拟计算,对结果做了分析比较表明,在炮检距和深度之比较大时,迭代法相对近似公式来说,具有明显更高的精度。

On the Calculation of the Coordinates of the Conversion Points

The up-and down-going travel path of the converted wave is asymmetrical, so the distance between conversion point and middle point has been changed with the P-wave-to-S-wave velocity ratio, the depth of reflector, offset and other factors. The key point for the converted wave velocity analysis and stacking is how to get a true common conversion point gathering. Then to make a good choice for the common conversion points is firstly to adopt the simple and effect method to calculate the coordinate of the conversion points. In this paper, in a single homogeneous layer, A comparison of the result has been made and the result shows that the iterative is more accurate when the ratio of offset and depth of reflector is large.