A Comparison Study of the Contributions of Additional Observations in the Sensitive Regions Identified by CNOP and FSV to Reducing Forecast Error Variance for the Typhoon Morakot          下载免费PDF全文

QIN Xiao-Hao 《大气和海洋科学快报》2010,3(5):258-262

The sensitive regions of conditional nonlinear optimal perturbations (CNOPs) and the first singular vector (FSV) for a northwest Pacific typhoon case are reported in this paper. A large number of probes have been designed in the above regions and the ensemble transform Kalman filter (ETKF) techniques are utilized to examine which approach can locate more appropriate regions for typhoon adaptive observations. The results show that, in general, the majority of the probes in the sensitive regions of CNOPs can reduce more forecast error variance than the probes in the sensitive regions of FSV. This implies that adaptive observations in the sensitive regions of CNOPs are more effective than in the sensitive regions of FSV. Furthermore, the reduction of the forecast error variance obtained by the best probe identified by CNOPs is twice the reduction of the forecast error variance obtained by FSV. This implies that dropping sondes, which is the best probe identified by CNOPs, can improve the forecast more than the best probe identified by FSV. These results indicate that the sensitive regions identified by CNOPs are more appropriate for adaptive observations than those identified by FSV.  相似文献   

一种确定联合反演中相对权比的两步法   总被引：2，自引：1，他引：1  

王乐洋  许才军  张朝玉 《测绘学报》2012,41(1):19-0

提出确定联合反演中相对权比的两步法。第1步是不考虑相对权比,建立两类或多类数据的联合反演模型,通过赫尔墨特方差分量估计使得两类或多类观测数据的单位权方差相等（或单位权方差的比值接近1）,从而理论上确定观测数据合理的权阵,同时对不同种类数据进行归一化;第2步是在获得合理的观测数据权阵之后,建立顾及相对权比的联合反演模型,...  相似文献   

GPS在轨卫星原子钟的稳定性分析     

李长会  闫国锋 《测绘与空间地理信息》2012,(7):106-108

导航卫星星载原子钟的相位或频率数据,作为导航系统应用研究的基础,将直接影响导航系统时间尺度建立以及定位的精度和准确性。本文针对由IGS官网提供的四种GPS卫星钟的钟差数据,采用修正阿伦方差进行了稳定性分析,得到了一些有益的结论。  相似文献   

GPS／GLoNASS组合定位的抗差Helmert方差分量估计模型     

高晓  戴吾蛟 《全球定位系统》2012,37(6):17-20,25

GPS和GLONASS存在系统差异,组合定位时,采用Helmert方差分量估计可得到更加准确的结果。但GNSS观测值常受到衍射信号和多路径效应的影响,使观测值存有粗差,从而导致Helmert方差分量估计的失真。为此,将抗差Helmert方差分量估计应用于GPS／GLONASS组合单点定位,实验结果表明：抗差Helmert方差分量估计可以有效地抑制组合系统粗差观测值的影响。  相似文献   

The variogram sill and the sample variance   总被引：1，自引：0，他引：1  

Randal J. Barnes 《Mathematical Geology》1991,23(4):673-678

The relationship between the sill of the variogram and the sample variance is explored. The common practice of using the sample variance as an estimate of the variogram sill is questioned, and a conceptual framework for determining the appropriateness of this heuristic is constructed.  相似文献   

区域化探异常研究方法探讨   总被引：1，自引：0，他引：1  

李武俊  唐开金 《陕西地质》1991,(1)

本文对区域化探异常图示、异常评序、可能成矿元素、综合解释及成矿预测等方面进行了探索性研究,这对异常深入的剖析研究,确定异常检查范围及成矿预测都十分有益。数据处理系统是在无 X—Y 绘图仪的 PC 微机上实现数据处理、成图及各类处理分析的程序软件。  相似文献   

A heuristic search method for optimal zonation of well logs   总被引：1，自引：0，他引：1  

Hui-Chuan Chen  J. H. Fang 《Mathematical Geology》1986,18(5):489-500

Optimal zonation of well-log data, that is, determining an optimal number of major segments such as waveforms in a log, may be achieved by employing a criterion of minimum variance (within a segment) and a heuristic search of potential boundary (link) points of digitized log data. This new method is based on an algorithm originally devised by D. M. Hawkins and D. F. Merriam in 1973. Their method can be improved by introducing a heuristic search procedure, thereby decreasing computer time by 7- to 50-fold, depending on the number of data points and configuration of the logs. Time saving is proportional to the size of the data set. Three examples—one hypothetical and two real—are used to illustrate the modification of the Hawkins and Merriam algorithm.Presented at the Geological Society of America Annual Meeting, Orlando, Florida, 1985.  相似文献   

方差分量估计的MINQE理论及其在摄影测量中的应用     

樊启斌 《武汉大学学报(信息科学版)》1990,(2)

本文深入研究了异方差分量模型的MINQE(U,I)准则的算法实现的可能性,所导出的约化算法具有压缩内存,提高运算速度等明显优点,因而具有实用意义。文中介绍了实现约化算法的计算机程序框图,并提供了数据例子。作者将方差分量估计的MINQE理论引入解析摄影测量平差实践,分别采用模拟数据和新滩滑坡监测数据研究了自检校光束法平差中随机模型的确定,结果表明,MINQE理论用于自检校的验后权估计是可行的。最后,作者就平差随机模型的扩展,以及MINQE理论的应用提出了进一步研究的几点设想。  相似文献   

精密重力网的定权及系统效应     

杨重谊 《武汉大学学报(信息科学版)》1990,(4)

对于精密重力网,如何确定各类观测值的权,如何剔除相对重力仪过多的参数,是目前尚未解决好的两个问题。本文讨论了利用方差分量估计确定各类观测值的权,利用几种假设检验选择附加参数的方法以及相关的几个问题。经过计算和比较分析,得到了较好的结果。  相似文献   

2000国家GPS大地控制网数据处理方法与结果   总被引：9，自引：2，他引：7  

唐颖哲  杨元喜  宋小勇 《大地测量与地球动力学》2003,23(3):77-82

介绍了我国GPS大地控制网的基本情况,阐述了结合地壳运动观测网络工程建立全国统一的“2000国家GPS大地控制网”的意义,并介绍了整网平差中采用的技术方法和最后平差结果及精度。  相似文献