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1.
《制图学和地理信息科学》2013,40(5):328-331
The Census Bureau is committed to using the Spatial Data Transfer Standard (SDTS) and is developing an extract from the Census TIGER? called the TIGER/SDTS?. A single file of the prototype TIGER/SDTS is now available with which interested data users may experiment. This paper will graphically describe some of the SDTS concepts and census geographic concepts used in the TIGER/SDTS. The Census TIGER? and the TIGER/SDTS? are trademarks of the Bureau of the Census. 相似文献
2.
《制图学和地理信息科学》2013,40(3):320-325
As this article is published, the U.S. Census Bureau is completing work for the twenty third decennial census of the United States. Once again, the MAF/TIGER system served as the geospatial infrastructure supporting numerous census operations and data collection, tabulation, and dissemination activities. From data collection to data dissemination we trace the recent activities of the 2010 Decennial Census of the United States to illustrate the role maps and geospatial data play in an increasing variety of public and private sector activities across the nation. To ensure a successful 2010 Census, millions of maps had to be created. This article will give an overview of the automated mapping system designed to create these maps. This includes a discussion about associated software needed and the variety of map types that were developed. Finally, future map production and geospatial activities at the Census Bureau will be discussed. 相似文献
3.
《制图学和地理信息科学》2013,40(1):89-97
The TIGER System is many things to many people. At this juncture, the TIGER System has fulfilled the precensus geographic support functions for which the Geography Division designed it. During the next 18 months, the TIGER System will support a number of functions needed to complete the tabulation of the collected data and make those data useful to the numerous constituencies that carry out the myriad tasks that define our lives. Simultaneously with the use of the TIGER System to support the data tabulation and dissemination missions of the Census Bureau, work will be under way to define a framework for the future of this bold new product – and this future looks bright. If the TIGER System is to be judged truly useful outside the Census Bureau, similar planning will need to be going on in offices and institutions across America. This is true especially in the context of geographic information system (GIS) applications involving the digital products of the TIGER System and the demographic data products of the 1990 census. 相似文献
4.
《制图学和地理信息科学》2013,40(2):217-223
The TIGER system was developed by the Geography Division of the U.S. Census Bureau to support agency censuses and surveys. The system has been crucial to meeting the demands placed on the U.S. Census Bureau. It has been widely used by the public for a large and diverse number of uses. As public uses evolved, demands evolved. In parallel, technology and spatial data collection evolved. TIGER should now support a larger purpose. This article discusses some developments of the TIGER system and presents some of the key components of TIGER modernization: improvement of positional accuracy, connection to the National Spatial Data Infrastructure (NSDI), and improved geographic analysis. 相似文献
5.
A Snake-based Approach for TIGER Road Data Conflation 总被引：1，自引：0，他引：1
《制图学和地理信息科学》2013,40(4):287-298
The TIGER (Topologically Integrated Geographic Encoding and Referencing) system has served the U.S. Census Bureau and other agencies' geographic needs successfully for two decades. Poor positional accuracy has however made it extremely difficult to integrate TIGER with advanced technologies and data sources such as GPS, high resolution imagery, and state/local GIS data. In this paper, a potential solution for conflation of TIGER road centerline data with other geospatial data is presented. The first two steps of the approach (feature matching and map alignment) remain the same as in traditional conflation. Following these steps, a third is added in which active contour models (snakes) are used to automatically move the vertices of TIGER roads to high-accuracy roads, rather than transferring attributes between the two datasets. This approach has benefits over traditional conflation methodology. It overcomes the problem of splitting vector road line segments, and it can be extended for vector imagery conflation as well. Thus, a variety of data sources (GIS, GPS, and Remote Sensing) could be used to improve TIGER data. Preliminary test results indicate that the three-step approach proposed in this paper performs very well. The positional accuracy of TIGER road centerline can be improved from an original 100 plus meters' RMS error to only 3 meters. Such an improvement can make TIGER data more useful for much broader application. 相似文献
6.
《制图学和地理信息科学》2013,40(5):278-293
The Spatial Data Transfer Standard (SDTS), after nine years of development, was approved on July 29, 1992, as FIPS Publication 173. The SDTS consists of three distinct parts. Part 1 is concerned with logical specifications required for spatial data transfer and has three major components: a conceptual model of spatial data, data quality report specifications, and detailed logical transfer format specifications for SDTS data sets. Part 2 provides a model for the definition of real-world spatial features, attributes, and attribute values and includes a standard but working and expandable list with definitions. Part 3 specifies the byte-level format implementation of the logical specifications in SDTS Part 1 using ISO/ANSI 8211 (FIPS 123), a general data exchange standard. 相似文献
7.
Recent developments in data visualization, developer Application Program Interfaces (APIs), and web services reinforce a long American tradition of statistical mapping and innovation at the US Census Bureau. Consistent with other international statistical agencies, the Census Bureau has used contemporary innovations in statistical mapping and data visualization to disseminate national census results for over 14 decades. The US Census Bureau’s data products and analyses have enabled decision makers and the public to access census results quickly and easily. The new information technology environment requires the Census Bureau to more rapidly expedite these results and deliver mapping products to new customers as well as to its traditional data consumers. The Census API has empowered developers and commercial companies to test the limits of a new emerging world of big data solutions. This article presents some of the most recent data visualization products from the Census Bureau, including an expanding Data Visualization Gallery to merge geospatial information and statistics on the map. 相似文献
8.
目前我国地名数据库的建设主要靠传统测绘手段完成,存在周期长、成本高、效率低的缺点。随着地理数据服务的发展,出现了一些在格式、尺度、范围、内容、现势性等方面具有差异性的免费地名数据库。本文提出了一种整合多开源网络地名数据库形成统一格式、多尺度、内容完备、现势性强的矢量地名库的方法。首先通过OGR和数据访问API构建不同文件格式的网络地名库的矢量格式转换模型,然后对多网络地名库进行矢量转换,最后对其进行数据预处理、数据处理、数据分类映射等处理过程建立矢量地名数据库。本文以香港地区的Geonames,GNS,OSM地名数据库整合为例,验证了方法的可行性。 相似文献
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10.
Positional Accuracy of TIGER 2000 and 2009 Road Networks 总被引：1，自引：0，他引：1
The Topologically Integrated Geographic Encoding and Referencing (TIGER) data are an essential part of the US Census and represent a critical element in the nation's spatial data infrastructure. TIGER data for the year 2000, however, are of limited positional accuracy and were deemed of insufficient quality to support the 2010 Census. In response the US Census Bureau embarked on the MAF/TIGER Accuracy Improvement Project (MTAIP) in an effort to improve the positional accuracy of the database, modernize the data processing environment and improve cooperation with partner agencies. Improved TIGER data were released for the entire US just before the 2010 Census. The current study characterizes the positional accuracy of the TIGER 2009 data compared with the TIGER 2000 data based on selected road intersections. Three US counties were identified as study areas and in each county 100 urban and 100 rural sample locations were selected. Features in the TIGER 2000 and 2009 data were compared with reference locations derived from high resolution natural color orthoimagery. Results indicate that TIGER 2009 data are much improved in terms of positional accuracy compared with the TIGER 2000 data, by at least one order of magnitude across urban and rural areas in all three counties for most accuracy metrics. TIGER 2009 is consistently more accurate in urban areas compared with rural areas, by a factor of at least two for most accuracy metrics. Despite the substantial improvement in positional accuracy, large positional errors of greater than 10 m are relatively common in the TIGER 2009 data, in most cases representing remnant segments of minor roads from older versions of the TIGER data. As a result, based on the US Census Bureau's suggested accuracy metric, the TIGER 2009 data meet the accuracy expectation of 7.6 m for two of the three urban areas but for none of the three rural areas. The suggested metric is based on the National Standard for Spatial Data Accuracy (NSSDA) protocol and was found to be very sensitive to the presence of a small number of very large errors. This presents challenges during attempts to characterize the accuracy of TIGER data or other spatial data using this protocol. 相似文献
11.
Walters WH 《The Cartographic journal》1997,34(1):29-30
"Public-Use Microdata Areas (PUMAs) are the smallest geographic units for which many U.S. Census variables are reported. In particular, 1990 microdata records for households and individuals can be aggregated only by PUMA, metropolitan area, state, and region. The Census Bureau distributes maps of these PUMAs only on paper, however, and only for individual states. This note describes the construction of a national, digital base map of the PUMAs used in the 1990 U.S. Census microdata files (5% sample)." 相似文献
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Certain types of two-dimensional (2-D) numerical remote sensing data can be losslessly and compactly compressed for archiving and distribution using standardized image formats. One common method for archiving and distributing data involves compressing data files using file compression utilities such as gzip and bzip2, which are widely available on UNIX and Linux operating systems. GZIP-compressed files and bzip2-compressed files must first be uncompressed before they can be read by a scientific application (e.g., MATLAB, IDL). Data stored using an image format, on the other hand, can be read directly by a scientific application supporting that format and, therefore, can be stored in compressed form, saving disk space. Moreover, wide use of image formats by data providers and wide support by scientific applications can reduce the need for providers of geophysical data to develop and maintain software customized for each type of dataset and reduce the need for users to develop and maintain or download and install such software. This letter demonstrates the utility of standardized image formats for losslessly compressing, archiving, and distributing 2-D geophysical data by comparing them with the traditional file compression utilities gzip and bzip2 on several types of remote sensing data. The formats studied include TIFF, PNG, lossless JPEG, JPEG-LS, and JPEG2000. PNG and TIFF are widely supported. JPEG2000 and JPEG-LS could become widely supported in the future. It is demonstrated that when the appropriate image format is selected, the compression ratios can be comparable to or better than those resulting from the use of file compression utilities. In particular, PNG, JPEG-LS, and JPEG2000 show promise for the types of data studied. 相似文献
14.
《制图学和地理信息科学》2013,40(5):315-320
The Digital Line Graph level 3 (DLG-3) is the term for U.S. Geological Survey digital spatial data stored in vector form. Prior to the approval of the Spatial Data Transfer Standard (SDTS) as a Federal Information Processing Standard (FIPS), a system was developed to convert a DLG-3 data set to a sample SDTS transfer. The specifications of the SDTS Topological Vector Profile were used for the transfer (U.S. Geological Survey 1992). The process required expertise in cartography, geography, and computer science. Analysis revealed requirements for processes to transform spatial addresses, to translate and map DLG-3 spatial objects and attribute pairs to the SDTS, to compile data not available in computer-readable form, and to convert files to FIPS 123 (ISO 8211) standard. Mapping data to the SDTS proved to be complex and highlighted the need for appropriate training with regard to the SDTS and FIPS 123. Several issues were raised, such as the source of data quality information, platforms supported by the FIPS 123 Function Library software, and attribute translation criteria. 相似文献
15.
针对一些通用的空间数据的数据交换格式进行了研究，并就不同数据格式的数据量进行了对比实验。结果表明，在栅格数据中，．bmp格式的数据量最大，.jpg格式和．gif格式的数据量较小；矢量格式的数据量的大小与空间数据的属性有关，在几种常用的矢量格式中，．e00格式的数据量最大。 相似文献
16.
电子测量仪器自动记录数据格式转换程序设计 总被引：2，自引：0，他引：2
电子测量仪器的广泛应用加快了测量速度,提高了测量内外业的工作效率.但是目前的数据格式和数据标准存在不统一,给内业处理和测绘软件的开发带来了许多麻烦.为解决原始测量数据与内业后处理软件匹配问题,本文选取了几种常用数据格式,包括LEICA TC1800原始观测数据格式(*GSI)、LEICA DNA2原始观测数据格式(*m... 相似文献
17.
介绍GPS接收机数据的RINEX标准交换格式,讨论二进制数据格式文件向文本文件转换的方法及需要注意的问题,通过分析HemisphereJ、avad、AC12、NavCom 4种不同OEM板二进制数据格式,指出GPS接收机的二进制数据文件向RINEX文件转换的一般方法,并编程实现所有程序,验证方法的正确性。 相似文献
18.
《制图学和地理信息科学》2013,40(4):321-344
In this paper I discuss the potential of U.S. Geological Survey Digital Line Graph data for applications to microcomputer-based cartographic and geographic information systems. The DLG-3 data base produced from 1:100,000-scale maps is the principal focus because of its importance in providing the cartographic framework for the 1990 decennial census. Topological relationships inherent in DLG-3 data are reviewed as a basis for discussion of how additional digital cartographic data, including the U.S. Geological Survey Land Use and Land Cover data can be converted to the same DLG-3 data structure. The development and applications of software implemented to manipulate DLG-3 data on a microcomputer are reviewed and illustrated through examples of DLG-3 formatted data. 相似文献
19.
《制图学和地理信息科学》2013,40(3):162-171
Developers of the Geographic Resources Analysis Support System (GRASS) at the U.S. Army Corps of Engineering Research Laboratories (USACERL) have been closely involved with the SDTS project since February 1992. Software for the exchange of data between GRASS and SDTS is near completion. Access to SDTS data via this software promises many benefits for GRASS users, but SDTS will also pose challenges to the GRASS user community just as it has for the creation of GRASS-SDTS software itself. Areas of difficulty include distinctions between SDTS and GRASS in the definition of certain spatial objects, SDTS metadata requirements, and accommodation within GRASS of the complex data attribute schemas that will be typical of SDTS data sets. 相似文献
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