转换波三参数速度分析及动校正方法

转换波时距方程的精度直接影响到转换波的速度分析和动校正的精度。现今应用较多的转换波时距方程中有双曲线方程（本文称为单参数方程）、双平方根方程（或称双参数方程）及高阶非双曲方程。本文从纵波大炮检距方程出发，针对转换波传播特点，推导出了能反映介质垂向非均质性的转换波三参数时距方程，其中三参数分别指纵波速度、横波速度和垂向非均质性。在此基础上，形成了转换波三参数速度分析及动校正方法。为了比较单参数方程、双参数方程和三参数方程的精度，利用这三种方程分别对合成模型数据和实际资料进行了处理，结果表明本文提出的转换波三参数方程的精度高于其他两种方程。

Three-parameter velocity analysis of converted wave and NMO method.

The precision of converted wave time-distance equation directly affects the velocity analysis of converted wave and its NMO precision. Common-used converted wave time-distance equations include hyperbolic equation (single-parameter equation called in the paper) ,double-square-root equation (or called double-parameter equation) and high-order non-hyperbolic equation. Coming from the P-wave larger-offset equation and faced with the feature of converted wave propagation,the paper deduced converted wave three-parameter time-distance equation that can reflect the vertical inho-mogeneity of media,among which the three parameters mean P-wave velocity, S-wave velocity and vertical inhomogeneity separately. On that basis, the methods for three-parameter velocity analysis and NMO of converted wave have been formed. In order to comparison among the single-parameter e-quation, double-parameter equation and three-parameter equation, we use these three equations to make syntheses data and process the real data,the results showed the converted wave three-parameter equation is superior to the other two equations in precision.