Parallel versions of prestack KirchhofT 3D integral migration algorithm, which is suitable forseismic data processing, are described in this paper. Firstly, the inherent parallel characteristics of seismicdata process...Parallel versions of prestack KirchhofT 3D integral migration algorithm, which is suitable forseismic data processing, are described in this paper. Firstly, the inherent parallel characteristics of seismicdata processing are analyzed. Then some principles in algorithm partition are discussed. Based on these analyses and the system architecture, communication mechanism, this algorithm is divided into four subtasksallocated to four nodes of 990 STAR-l. Then we describe in detail a module-partitioning method-theI / O processing and communication are separated from the computation process, the processes includingI / O processing and communication are allocated to transputer T805 and the other is allocated to processori860. These two processes are synchronized by shared memory and memory-lock mechanism, but the communication betWeen different nodes is implemented through links of transputer. Load balance among fourprocessor modules is performed dynamically. Finally, we discussed the speed--up of the parallel versions ofprestack KirchhofT 3D integral migration algorithm running on four nodes. Some further researches are also melltioned in this paper.展开更多
叠前反演是获取地下介质弹性参数的一种重要手段,马尔可夫蒙特卡洛(Markov Chain Monte Carlo,MCMC)算法是叠前反演求解的经典方法。相比于传统的数值优化算法和线性反演方法,MCMC反演算法具备更高的精度,但仍然存在依赖初始模型、计算...叠前反演是获取地下介质弹性参数的一种重要手段,马尔可夫蒙特卡洛(Markov Chain Monte Carlo,MCMC)算法是叠前反演求解的经典方法。相比于传统的数值优化算法和线性反演方法,MCMC反演算法具备更高的精度,但仍然存在依赖初始模型、计算耗时长和不确定性大等问题。为此,对常规MCMC反演算法进行改进,提出基于构造倾角约束的BLI-MCMC叠前随机反演方法。首先,将地质构造倾角加入先验约束信息中,提高反演的采样效率,降低反演结果的不确定性;然后,利用贝叶斯线性反演(Bayesian Linear Inversion,BLI)算法为MCMC反演提供良好的初始模型,并作为迭代起点,缩短马尔科夫链的燃烧时间,从初始模型角度提高反演的效率。模拟数据和实际资料应用结果均表明,改进后的方法能够显著提高反演精度和效率,保持了地下介质较高的横向连续性。该方法可为地下起伏介质的反演提供技术支撑。展开更多
山地地区地下地质结构复杂,地表高差大,变化剧烈.目前该类地区地震勘探中主要的成像手段依然是Kirchhoff叠前时间偏移.但地表高程的剧烈变化使叠前时间偏移的基准面很难选择.本文在传统方法的基础上,提出了一种在浮动基准面上修正常规...山地地区地下地质结构复杂,地表高差大,变化剧烈.目前该类地区地震勘探中主要的成像手段依然是Kirchhoff叠前时间偏移.但地表高程的剧烈变化使叠前时间偏移的基准面很难选择.本文在传统方法的基础上,提出了一种在浮动基准面上修正常规叠前时间偏移走时计算的叠前时间偏移方法,该方法能够很大程度上提高山地地区、特别是地表高差变化大地区的成像效果.本文还介绍了GPU在叠前时间偏移上的应用,通过GPU对叠前时间偏移的优化和实现,得出如下结论:应用单颗NVIDIA Tesla C1060 GPU进行叠前时间偏移,相比应用主频2.5 GHz的单核CPU计算效率可提高70倍以上.展开更多
文摘Parallel versions of prestack KirchhofT 3D integral migration algorithm, which is suitable forseismic data processing, are described in this paper. Firstly, the inherent parallel characteristics of seismicdata processing are analyzed. Then some principles in algorithm partition are discussed. Based on these analyses and the system architecture, communication mechanism, this algorithm is divided into four subtasksallocated to four nodes of 990 STAR-l. Then we describe in detail a module-partitioning method-theI / O processing and communication are separated from the computation process, the processes includingI / O processing and communication are allocated to transputer T805 and the other is allocated to processori860. These two processes are synchronized by shared memory and memory-lock mechanism, but the communication betWeen different nodes is implemented through links of transputer. Load balance among fourprocessor modules is performed dynamically. Finally, we discussed the speed--up of the parallel versions ofprestack KirchhofT 3D integral migration algorithm running on four nodes. Some further researches are also melltioned in this paper.
文摘叠前反演是获取地下介质弹性参数的一种重要手段,马尔可夫蒙特卡洛(Markov Chain Monte Carlo,MCMC)算法是叠前反演求解的经典方法。相比于传统的数值优化算法和线性反演方法,MCMC反演算法具备更高的精度,但仍然存在依赖初始模型、计算耗时长和不确定性大等问题。为此,对常规MCMC反演算法进行改进,提出基于构造倾角约束的BLI-MCMC叠前随机反演方法。首先,将地质构造倾角加入先验约束信息中,提高反演的采样效率,降低反演结果的不确定性;然后,利用贝叶斯线性反演(Bayesian Linear Inversion,BLI)算法为MCMC反演提供良好的初始模型,并作为迭代起点,缩短马尔科夫链的燃烧时间,从初始模型角度提高反演的效率。模拟数据和实际资料应用结果均表明,改进后的方法能够显著提高反演精度和效率,保持了地下介质较高的横向连续性。该方法可为地下起伏介质的反演提供技术支撑。
文摘山地地区地下地质结构复杂,地表高差大,变化剧烈.目前该类地区地震勘探中主要的成像手段依然是Kirchhoff叠前时间偏移.但地表高程的剧烈变化使叠前时间偏移的基准面很难选择.本文在传统方法的基础上,提出了一种在浮动基准面上修正常规叠前时间偏移走时计算的叠前时间偏移方法,该方法能够很大程度上提高山地地区、特别是地表高差变化大地区的成像效果.本文还介绍了GPU在叠前时间偏移上的应用,通过GPU对叠前时间偏移的优化和实现,得出如下结论:应用单颗NVIDIA Tesla C1060 GPU进行叠前时间偏移,相比应用主频2.5 GHz的单核CPU计算效率可提高70倍以上.
