角度域共成像点道集的提取与叠加成像

基于共成像点道集的速度分析是速度分析方法中常用的一种方法。共成像点道集有偏移距域共成像点道集、炮域共成像点道集和角度域共成像点道集等。在复杂地区，偏移距域共成像点道集和炮域共成像点道集存在运动学和动力学假象，而角度域共成像点道集则有效地克服了这个问题。首先分析了角度域共成像点道集的特性，讨论了如何较准确地提取角度域共成像点道集；然后分别利用单平方根算子和双平方根算子波动方程偏移方法提取了偏移距域共成像点道集；接下来应用插值法将偏移距域共成像点道集投影到角度域，生成角度域共成像点道集；最后进行了角度域叠加成像。模型试算结果表明：与常规波动方程偏移方法相比，角度域叠加成像能够改善局部成像质量。

Extraction and stack imaging of common imaging point gathers in angle domain

Velocity analysis based on common imaging point gathers becomes more and more important now.The common imaging point gathers includes offset, shot, and angle domains etc. In a complex area, common imaging point gathers in offset and shot domains have kinematic and kinetic artifacts. But the common imaging point gathers in angle domain can effectively overcome this problem. Firstly, the characteristics of common imaging point gathers in angle domain were analyzed and the problem of how to extract common imaging point gathers exactly in an angle domain discussed. Then, common imaging point gathers in offset domain were respectively extracted based on a single square root operator and double square root operator wave equation migration. After that, interpolation was used to transform common imaging point gathers from offset domain to angle domain, and to generate common imaging point gathers in angle domain. Finally, stack imaging was carried out in angle domain. The test of model proves that compared with conventional wave equation migration methods, stack imaging in angle domain can improve local imaging quality.