VTI介质各向异性参数角道集层析反演

目前的各向异性层析方法主要利用不同范围的炮检距信息或角道集信息反演各向异性参数，但缺少对反演中角道集划分的定义。为此，首先根据旅行时对Thmosen参数的一阶偏导数和对Thmosen参数及相角的二阶偏导数进行敏感性分析，明确定义小、中、大角道集的范围；然后利用各向同性单程波偏移及速度层析建立基础速度场；再利用Poynting矢量提取VTI介质逆时偏移角道集；最后利用小角度道集剩余曲率反演Thmosen速度参数、中角度道集反演Thmosen参数δ、大角度道集反演Thmosen参数ε。简单洼陷模型试算结果说明方法的正确性，复杂构造模型试算结果验证了方法的适用性。

VTI medium anisotropic parameter tomography inversion based on angle domain common imaging gathers

Current anisotropic tomography methods mainly use the information of different offset ranges or information of angle domain common imaging gathers (ADCIGs) to perform the anisotropic parameter inversion,but lack the definition of partition in ADCIGs.Firstly,according to the travel time first-order partial derivative to Thomsen parameter and the travel time second-order partial derivative to Thomsen parameter and phase angle,the range of small,medium and large ADCIGs is clearly defined.Then the basic velocity field is established by an isotropic one-way wave migration and velocity tomography.The ADCIGs of VTI media inverse-time migration is extracted by Poynting vector method.Finally,we can develop a method to invert the V_P0 with the small angle range gathers information,δ with the middle range,and ε with the large range.Trial results of a simple concave model illustrate the correctness of the proposed method,and trial results of a complex structural model verify the applicability of the proposed method.