GPS“射线打靶”模式高效数值方法的研究及其并行实现  

THE TIME-SAVING NUMERICAL METHOD FOR GPS/MET OBSERVATION OPERATOR AND ITS PARALLEL COMPUTING

作　　者：李树勇[1] 王斌[1] 

机构地区：[1]LASG中国科学院大气物理研究所,北京100029

出　　处：《计算物理》2001年第6期491-496,共6页Chinese Journal of Computational Physics

基　　金：国家重点基础研究发展规划项目 (19990 3 2 80 1);国家杰出青年科学基金 (4982 5 10 9)资助项目

摘　　要：全球定位系统 (GPS)“射线打靶法”是GPS MET(气象 )资料变分同化中一种自成一体的观测算子 ,由于其计算量非常巨大而一直没能在资料同化中得到使用 .为了减少该观测算子的计算量 ,针对GPS射线轨迹方程为一可分Hamilton系统的特点 ,采用二阶经济辛格式求解 ,与经典的四阶Runge Kuntta法相比 ,不仅计算准确度没有降低甚至有所改善 ,而且节省近 4倍的计算时间 .同时进一步研究了改进后的GPS“射线打靶”The Global Positioning System(GPS) ray shooting method is a self sufficient observation operator in GPS/MET(Meteorology)data variational assimilation.The huge computation of the GPS ray shooting method,however,makes it impossible so far to be applied in data assimilation and operational prediction.In order to reduce the huge computation,a 2nd order timesaving symplectic scheme is used to solve the equations of the GPS ray trajectory due to its separable Hamiltonian nature.Not only does it save 75% of the CPU time the old GPS ray shooting model using 4th order Runge Kutta method takes,but also does the simulation accuracy be improved slightly to some extent.Then the parallel computing of the new GPS ray shooting model is studied.The speed up and the parallel efficiency are both very high.

关 键 词：GPS射线打靶 辛格式 并行计算 全球定位系统 数值分析 GPS掩星 大气遥感 

分 类 号：P407[天文地球—大气科学及气象学] O246[理学—计算数学]