TN242 2003010249ICF瞄准定位系统的设计=Design on a collimation and locationsystem in ICF[刊,中]/李良钰(中科院上海光机所联合室.上海(201800)),王仕璠…//光子学报.-2002,311)-107-109将"神光Ⅱ"装置的原瞄准定位系统...TN242 2003010249ICF瞄准定位系统的设计=Design on a collimation and locationsystem in ICF[刊,中]/李良钰(中科院上海光机所联合室.上海(201800)),王仕璠…//光子学报.-2002,311)-107-109将"神光Ⅱ"装置的原瞄准定位系统改为全反射式,可以用各波长的三倍频激光打靶。介绍一个双球面的反射系统的光学设计和测试结果。图4表1参3(方舟)展开更多
The Proper Orthogonal Decomposition(POD)-based ensemble four-dimensional variational(4DVar) assimilation method(POD4DEnVar) was proposed to combine the strengths of EnKF(i.e.,the ensemble Kalman filter) and 4DVar assi...The Proper Orthogonal Decomposition(POD)-based ensemble four-dimensional variational(4DVar) assimilation method(POD4DEnVar) was proposed to combine the strengths of EnKF(i.e.,the ensemble Kalman filter) and 4DVar assimilation methods.Recently,a POD4DEnVar-based radar data assimilation scheme(PRAS) was built and its effectiveness was demonstrated.POD4 DEnVar is based on the assumption of a linear relationship between the model perturbations(MPs)and the observation perturbations(OPs);however,this assumption is likely to be destroyed by the highly non-linear forecast model or observation operator.To address this issue,using the Gauss-Newton iterative method,the nonlinear least squares enhanced POD4 DEnVar algorithm(referred to as NLS-4DVar) was proposed.Naturally,the PRAS was upgraded to form the NLS-4DVar-based radar data assimilation scheme(NRAS).To evaluate the performance of NRAS against PRAS,observing system simulation experiments(OSSEs) were conducted to assimilate reflectivity and radial velocity individually,with one,two,and three iterations.The results demonstrated that the NRAS outperformed PRAS in improving the initial condition and the forecasting of model variables and rainfall.The NRAS,with a smaller number of iterations,can yield a convergent result.In contrast to the situation when assimilating radial velocity,the advantages of NRAS over PRAS were more obvious when assimilating reflectivity.展开更多
文摘TN242 2003010249ICF瞄准定位系统的设计=Design on a collimation and locationsystem in ICF[刊,中]/李良钰(中科院上海光机所联合室.上海(201800)),王仕璠…//光子学报.-2002,311)-107-109将"神光Ⅱ"装置的原瞄准定位系统改为全反射式,可以用各波长的三倍频激光打靶。介绍一个双球面的反射系统的光学设计和测试结果。图4表1参3(方舟)
基金partially supported by theNational Key Research and Development Program of China(Grant No.2016YFA0600203)the High-resolution Earth Observation System Major Special Project(CHEOS)(Grant No.32-Y20A17-9001-15/17)+1 种基金the National Natural Science Foundation of China(Grant No.41575100)the Special Fund for Meteorological Scientific Research in Public Interest(Grant No.GYHY201306045)
文摘The Proper Orthogonal Decomposition(POD)-based ensemble four-dimensional variational(4DVar) assimilation method(POD4DEnVar) was proposed to combine the strengths of EnKF(i.e.,the ensemble Kalman filter) and 4DVar assimilation methods.Recently,a POD4DEnVar-based radar data assimilation scheme(PRAS) was built and its effectiveness was demonstrated.POD4 DEnVar is based on the assumption of a linear relationship between the model perturbations(MPs)and the observation perturbations(OPs);however,this assumption is likely to be destroyed by the highly non-linear forecast model or observation operator.To address this issue,using the Gauss-Newton iterative method,the nonlinear least squares enhanced POD4 DEnVar algorithm(referred to as NLS-4DVar) was proposed.Naturally,the PRAS was upgraded to form the NLS-4DVar-based radar data assimilation scheme(NRAS).To evaluate the performance of NRAS against PRAS,observing system simulation experiments(OSSEs) were conducted to assimilate reflectivity and radial velocity individually,with one,two,and three iterations.The results demonstrated that the NRAS outperformed PRAS in improving the initial condition and the forecasting of model variables and rainfall.The NRAS,with a smaller number of iterations,can yield a convergent result.In contrast to the situation when assimilating radial velocity,the advantages of NRAS over PRAS were more obvious when assimilating reflectivity.
