基于MPI+OpenMP的时间域航空电磁快速正演算法  

Research on time domain airborne electromagnetic fast forward algorithm based on MPI+OpenMP

作　　者：任运通 李貅[1] 齐彦福 曹华科 REN Yun-Tong;LI Xiu;QI Yan-Fu;CAO Hua-Ke(College of Geological Engineering and Geomatics,Chang'an University,Xi'an 710054,China)

机构地区：[1]长安大学地质工程与测绘学院,陕西西安710054

出　　处：《物探与化探》2020年第2期290-299,共10页Geophysical and Geochemical Exploration

基　　金：国家重点研发计划项目(2017YFC1502605);国家自然科学基金重点项目(41830101)。

摘　　要：时间域有限元算法已被广泛应用于航空电磁三维正演模拟当中,然而由于航空电磁测区面积大,且采样密集,造成正演计算量巨大,传统的串行算法已经无法满足计算效率要求,为此,开展了并行加速算法研究以解决计算效率不足的问题。基于航空电磁系统的影响范围有限,采用局部网格技术将计算任务划分成多个子网格,即每个发射源一套网格,各网格的正演计算相互独立,不存在数据依赖性,具有很好的可并行性;利用MPI技术对多个子网格正演任务进行分配,在各个进程上进行并行计算;针对每个正演子网格,在进行时间域有限元算法正演模拟过程中,采用OpenMP技术对单元矩阵进行并行计算。典型地电模型的数值模拟结果表明本文开发的MPI+OpenMP并行正演算法可以有效提高正演速度,最高加速比可达10倍。The time domain finite element algorithm has been widely used in airborne electromagnetic three-dimensional forward modeling. However, due to the large airborne electromagnetic measurement area and dense sampling, the forward calculation is huge, and the traditional serial algorithm cannot meet the calculation efficiency requirements. In view of such a situation, the authors carried out parallel acceleration algorithm research to solve the problem of insufficient computational efficiency. Based on the limited range of influence of aviation electromagnetic system, the local grid technology is used to divide the computing task into multiple sub-grids, that is, a set of grids for each source, and the forward calculations of each grid are independent of each other, and hence no data dependency is existent and there is good parallelism. In this paper, MPI technology is used to allocate multiple sub-grid forward tasks, and parallel computing is performed on each process. For each forward subgrid, in the forward modeling of the time domain finite element algorithm, the parallel matrix is calculated by OpenMP technology. The numerical simulation results of the typical electrical model show that the MPI+OpenMP parallel forward algorithm developed in this paper can effectively improve the forward speed, and the maximum acceleration ratio can reach 10 times.

关 键 词：时间域航空电磁 MPI OPENMP 有限元 

分 类 号：P631[天文地球—地质矿产勘探]