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虚拟国际规范文档——连接德国国家图书馆和美国国会图书馆的规范文档 被引量:15
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作者 rick bennett Christina Hengel-Dittrich +2 位作者 Edward T.O’Neill Barbara B.Tillett 顾犇 《国家图书馆学刊》 2006年第4期87-91,共5页
德国国家图书馆、美国国会图书馆和OCLC联机计算机图书馆中心联合开发了一个个人名称的虚拟国际规范文档(VIAF),它连接世界各国国家书目机构的规范记录,并免费提供网上检索,以证明自动连接不同国家规范文档的规范记录的可行性和优点。... 德国国家图书馆、美国国会图书馆和OCLC联机计算机图书馆中心联合开发了一个个人名称的虚拟国际规范文档(VIAF),它连接世界各国国家书目机构的规范记录,并免费提供网上检索,以证明自动连接不同国家规范文档的规范记录的可行性和优点。美国国会图书馆和德国国家图书馆的规范文档和书目文档被用来创建初始的VIAF,其中包括600多万个名称和50多万个连接。该项目的一个关键点是利用规范记录和其对应书目记录的信息开发自动名称匹配算法。该项目显示了用算法建立不同国家规范文档的个人名称之间连接的实用性。VIAF项目的长远目标是将许多国家图书馆和其他重要来源的规范名称结合起来,形成一个共享的全球规范服务。参考文献3。 展开更多
关键词 VIAF 虚拟国际规范文档 规范文档 规范记录 匹配
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Assessment of Pseudorange Multipath at Continuous GPS Stations in Mexico 被引量:3
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作者 G. Esteban Vázquez rick bennett Joshua Spinler 《Positioning》 2013年第3期253-265,共13页
We conducted a study to quantify the amount of pseudorange multipath at continuous Global Positioning System (CGPS) stations in the Mexican territory. These CGPS stations serve as reference stations enabling rapid hig... We conducted a study to quantify the amount of pseudorange multipath at continuous Global Positioning System (CGPS) stations in the Mexican territory. These CGPS stations serve as reference stations enabling rapid high-precision three-dimensional positioning capabilities, supporting a number of commercial and public safety applications. We studied CGPS data from a large number of publicly available networks spanning Mexico. These include the RGNA (National Active Geodetic Network) administered by INEGI (National Institute of Statistics and Geography), the PBO network (Plate Boundary Observatory) funded by the National Science Foundation (NSF) and operated by UNAVCO (University NAVstar Consortium), the Southern California Integrated GPS Network (SCIGN), which is a collaboration effort of the United States Geological Survey (USGS), Scripps Institution of Oceanography and the Jet Propulsion Laboratory (JPL), the UNAM network, operated by the National Seismological System (SSN) and the Institute of Geophysics of the National Autonomous University of Mexico (UNAM), the Suominet Geodetic Network (SNG) and the CORS (Continuously Operating Reference Station) network, operated by the Federal Aviation Administration (FAA). We evaluated a total of 53 CGPS stations, where dual-frequency geodetic-grade receivers collected GPS data continuously during the period from 1994 to 2012. Despite carefully selected locations, all GPS stations are, to some extent, affected by the presence of signal multipath. For GPS network users that rely on pseudorange observables, the existence of pseudorange multipath could be a critical source of error depending on the time scale of the application. Thus, to identify the most and the least affected GPS stations, we analyzed the averaged daily root mean square pseudorange multipath variations (MP1-RMS and MP2-RMS) for all feasible satellites tracked by the CGPS networks. We investigated the sources of multipath, including changes associated with hardware replacement (i.e., receiver and antenna type) and receiver firmware upgrades. 展开更多
关键词 Pseudorange MULTIPATH GPS NETWORK
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