论文部分内容阅读
用慢度分块均匀正方形模型将介质参数化，仅在正方形单元的边界上设置计算结点，这些结点构成界面网．根据Ｈｕｖｓｅｎｓ和Ｆｅｒｍａｔ原理，由不断扩张、收缩的波前点扫描代替波前面搜索，在波前点附近点的局部最小走时计算中对波前点之间的走时使用双曲线近似，通过比较确定最小走时和相应的次级源位置，记录在以界面网点位置为指针的３个一维数组中．借助这些数组通过向源搜索可计算任意点（包括界面网以外的点）上的全局最小走时和射线路径．这一方法不受介质慢度差异大小限制，占内存少，计算速度较快，适于走时反演和以Ｍａｓｌｏｖ射线理论为基础的波场计算．
The media is parameterized with a slow-rate, uniform square model, with computational nodes set only on the boundaries of the square elements, which form the interface mesh. According to the principle of Huvsens and Fermat, the wavefront scan of the expanding and contracting is replaced by the wavefront search, hyperbolic approximation is used to calculate the travel time between wavefront points in the local minimum traveltime calculation near the wavefront, and the minimum Travel times and corresponding secondary source locations are recorded in three one-dimensional arrays with the interface dot location as a pointer. With these arrays, you can calculate the global minimum traveltimes and ray paths at any point (including points outside the interface mesh) by searching the source. This method is not limited by the difference of medium slowness, accounting for less memory and faster calculation, suitable for time-of-flight inversion and wavefield calculation based on Maslov ray theory.