ARGO剖面浮标数据质量控制过程剖析   总被引：12，自引：4，他引：12  

童明荣  刘增宏  孙朝辉  朱伯康  许建平 《海洋技术学报》2003,22(4):79-84

ARGO计划的观测目标是能取得精度分别为0．5℃和0．01PSU的海水温度和盐度资料。然而，由于目前海水盐度是采用海水电导率间接导出的，而测量海水电导率的传感器很容易产生偏差。因此，必须对获得的ARGO数据进行质量控制。文章详细介绍了ARGO剖面浮标资料实时质量控制模式和延时质量控制模式及其采用的质量控制方法等。  相似文献   

利用零偏移VSP资料估计介质品质因子方法研究   总被引：18，自引：3，他引：15       下载免费PDF全文

高静怀  杨森林 《地球物理学报》2007,50(4):1198-1209

利用峰值频率移动法估算零偏VSP资料的品质因子Q．该方法用Ricker子波和匹配地震子波分别逼近零相位和混合相位的震源子波,得到了峰值频率移动法估计Q值的公式．进而针对常规方法估计的地震子波峰值频率精度不高的问题,提出了估计地震子波峰值频率的特征结构法．通过合成零偏VSP资料的仿真试验,验证了峰值频率移动法估计Q值的正确性．仿真结果表明,与快速Fourier变换和Burg最大熵方法相比较,特征结构法得到的峰值频率和Q值精度高一些．仿真结果也表明,用峰值频率移动法估计Q值时需要选取恰当的子波参数,否则影响Q值估计的精度．  相似文献   

MULTIVARIATE SELECTION OF VARIABLES IN INDUSTRIAL QUALITY CONTROL:OPTIMIZING AVIATION FUEL FINAL CONTROL     

J.M.ANDRADE  D.PRADA  S.MUNIATEGUI Department of Analytical Chemistry  Universidade da Corun  La Zapateir  E- Corun  Spain  B.GOMEZ  M.PAN Analytical Laboratory  Complejo Industrial Repsol Petróleo S.A.de La Corun  Poligono Bens  Corun  Spain Author to whom correspondence should be addressed. 《地理学报(英文版)》1993,(5)

This paper deals with a typical question encountered in all industrial analytical laboratories:are all thetests performed in the laboratory to characterize the final product really necessary?In this work the cross-validation technique,Procrustes rotation techniques and statistical variable selection have been used toreduce the 26 initial British Petroleum and ASTM kerosene specification tests to ten'essential'ones.Statistical as well as chemical considerations were used to select the optimum subset of original variablesto be retained from all the possible ones.  相似文献   

Application of the hydrologic visibility concept to estimate rainfall measurement quality of two planned weather radars     

D. Faure  G. Delrieu  P. Tabary  J. Parent Du Chatelet  M. Guimera 《Atmospheric Research》2005,77(1-4):232

This paper presents a practical application of the “hydrologic visibility” concept to select the future site of two planned weather radars of the French national network ARAMIS. This selection was realised by simulating the errors in radar rainfall measurement due to interactions of the radar beam with relief, and to the vertical variation of the radar reflectivity with altitude. Results show the interest of these simulations to optimise the radar location according to the objectives of radar coverage. Beyond these results, this paper highlights aspects interesting for hydrology: this type of simulation can be used to assess the radar measurement quality before initiating a quantitative exploitation of radar data, and before making a comparison or a combination with rain gauge data.  相似文献   

Quality control algorithms for rainfall measurements     

Claudia Golz  Thomas Einfalt  Marco Gabella  Urs Germann   《Atmospheric Research》2005,77(1-4):247

One of the basic requirements for a scientific use of rain data from raingauges, ground and space radars is data quality control. Rain data could be used more intensively in many fields of activity (meteorology, hydrology, etc.), if the achievable data quality could be improved. This depends on the available data quality delivered by the measuring devices and the data quality enhancement procedures. To get an overview of the existing algorithms a literature review and literature pool have been produced. The diverse algorithms have been evaluated to meet VOLTAIRE objectives and sorted in different groups. To test the chosen algorithms an algorithm pool has been established, where the software is collected. A large part of this work presented here is implemented in the scope of the EU-project VOLTAIRE (Validation of multisensors precipitation fields and numerical modeling in Mediterranean test sites).  相似文献   

Assessing spatial and attribute errors in large national datasets for population distribution models: a case study of Philadelphia county schools     

Lauren Patterson  Marie Urban  Aaron Myers  Budhendra Bhaduri  Eddie Bright  Phillip Coleman 《GeoJournal》2007,69(1-2):93-102

Geospatial technologies and digital data have developed and disseminated rapidly in conjunction with increasing computing efficiency and Internet availability. The ability to store and transmit large datasets has encouraged the development of national infrastructure datasets in geospatial formats. National datasets are used by numerous agencies for analysis and modeling purposes because these datasets are standardized and considered to be of acceptable accuracy for national scale applications. At Oak Ridge National Laboratory a population model has been developed that incorporates national schools data as one of the model inputs. This paper evaluates spatial and attribute inaccuracies present within two national school datasets, Tele Atlas North America and National Center of Education Statistics (NCES). Schools are an important component of the population model, because they are spatially dense clusters of vulnerable populations. It is therefore essential to validate the quality of school input data. Schools were also chosen since a validated schools dataset was produced in geospatial format for Philadelphia County; thereby enabling a comparison between a local dataset and the national datasets. Analyses found the national datasets are not standardized and incomplete, containing 76 to 90 percent of existing schools. The temporal accuracy of updating annual enrollment values resulted in 89 percent inaccuracy for 2003. Spatial rectification was required for 87 percent of NCES points, of which 58 percent of the errors were attributed to the geocoding process. Lastly, it was found that by combining the two national datasets, the resultant dataset provided a more useful and accurate solution.  相似文献   

滇中红层工程地质特性研究     

刘成 《云南地质》2007,26(4):428-438

介绍滇中红层形成的地质历史背景,红层分布范围,主要地层岩性及区内地质构造。重点讨论滇中红层特别是红层软岩的岩体原生结构,及后期受构造改造的岩体结构特性,岩体风化特性,岩体水理作用特性,岩体物理力学性质等四方面的工程地质特性。  相似文献   

GIS空间数据不确定性与质量控制的研究现状   总被引：28，自引：1，他引：28  

刘大杰  刘春 《测绘工程》2001,10(1):6-10

GIS空间数据不确定性和质量控制的研究是GIS基础理论问题研究中的一个重要内容。文中具体介绍了对该问题研究的几个阶段，对目前这一理论问题的研究现状作了简要介绍，并对GIS数据质量控制的策略提出一些看法。  相似文献   

绝对重力与相对重力混合平差的基准及质量控制   总被引：5，自引：0，他引：5  

杨元喜  郭春喜  刘念  丘其宪 《测绘工程》2001,10(2):11-14,19

绝对重力与相对重力测量混合平差是综合利用各种重力测量资料确定重力网基准，提高重力网综合质量的有效途径，文中首先从重力观测的系统误差入手，讨论重力网平差的函数模型；进而根据两类重力观测信息对重力基准的贡献，分析了不同平差方法所对应的各类基准及基统计意义与可靠性；最后对重力网平差的质量控制方法进行了讨论。  相似文献   

Self‐purification in Upland and Lowland Streams     

Ines Heidenwag  Uta Langheinrich  Volker Lüderitz 《洁净——土壤、空气、水》2001,29(1):22-33

Ecological investigations at four streams in Saxony‐Anhalt have shown that there are considerable differences between the self‐purification power of upland and lowland streams. This result is reflected in chemistry and in microbiology. The structure of the bottom substrate mainly influences the degree of self‐purification in connection with rate of flow and flow velocity. The results and differences are demonstrated using the example of Katzsohlbach in the landscape unit “Mittel‐ and Unterharz” and the stream Olbe in the landscape unit “Magdeburger Börde”.  相似文献