转换波处理比纯波型处理更严格地依赖于所涉及的岩石速度的物理假设,因为不仅是时差而且还有成像点本身的偏移都依赖于介质的物理参数。因此,均匀和各向同性的不切实际的假设比对纯波型传播更加危险,后者成像点的偏移是由几何学确定而非物理学确定。在层状各向异性介质中,一个有效速度比γ_(eff)≡γ_2 ~2/γ_0(式中,γ_0≡V_P/V_S是平均垂直速度比,γ_2是相应的短排列时差速度比)控制了大部分转换点偏移的特征。如果能在P波和转换波相应反射同相轴之间建立一个恰当的关系,那么,这些比值就能从P波和转换波数据中得到。简单地根据γ_0而不是γ_(eff)的采集设计能得到次优化的数据采集结果。针对均匀各向同性介质的应用算法的计算机程序可以勉强处理层状各向异性介质,把γ_(eff)简单地看作为输入一个速度比函数,有时可得到较好的精度。但是,简单的闭型解不用这些严格的假设就能消除双向型和后双曲型时差并计算转换点偏移。在这些公式中,最好是使用(相对深度而言)垂直旅行时作为独立变量,因为深度的确定在存在极各向异性时是不精确的,可能要推迟到处理流程的后面去做。如果地下有横向变化和(或)方位各向异性,那么,转换波在炮点和检波点位置交换的情况下,其数据不是不变的因此,一个中间放炮排列的道集会有非对称的时差尤其是在3-D勘探的情况下要是忽略了转换波速度场的这种单向特征就会导致成像错误 Converted wave processing relies more strictly on the physical assumptions of the rock velocity involved than pure wave processing because not only the time difference but also the shift of the imaging point itself depends on the physical parameters of the medium. Therefore, the unrealistic assumptions of uniform and isotropy are more dangerous than the propagation of pure wave type, the shift of the latter imaging point is determined by geometry rather than physics. In laminar anisotropic media, an effective velocity ratio γ_effγ ≡γ_2 ~ 2 / γ_0 (where γ_0≡V_P / V_S is the average vertical velocity ratio and γ_2 is the corresponding shortest alignment velocity ratio) is controlled Most of the conversion point offset characteristics. These ratios can be derived from P-wave and converted-wave data if an appropriate relationship is established between the P-wave and the corresponding reflection events of the converted wave. Suboptimal data acquisition results are obtained simply from the acquisition design for γ_0 instead of γ_eff. Computer programs that apply algorithms for homogeneous isotropic media can barely handle laminar anisotropy media and simply view γ eff as input to a velocity ratio function, sometimes with better accuracy. However, a simple closed-form solution eliminates bi-directional and post-hyperbolic time differences and computes shift point offsets without these strict assumptions. In these formulas, it is best to use (relative depth) as an independent variable for vertical travel because the determination of depth is imprecise in the presence of polar anisotropy and may be delayed until after the processing flow. If there is lateral variation and / or azimuthal anisotropy in the subsurface, then the converted data will not change without any change in the position of the shot and checkpoint exchange. Therefore, an asymmetrical time difference will occur in a set of shots arranged in the middle Especially in the case of 3-D exploration, omission of this one-way feature of the converted wave velocity field leads to imaging errors