The WebTIGER application allows those with a Web browser to view and download Topologically Integrated Geographic Encoding and Referencing (TIGER) data encoded in a vendor neutral format -- Geography Markup Language (GML) -- an OGC specification for encoding geographic features in XML. This new TIGER/GMLÂ¿ata format is being tested for public acceptance as a standards-based alternative to the TIGER/Line format currently used to distribute TIGER data. WebTIGER users can also view JPEG, PNG, and TIFF images and SVG maps of the TIGER/GML data.
In addition to managing the nation's collection of demographic and economic statistical data, the US Census Bureau is responsible for a critical collection of geographic data that gives the location of the people and businesses the summary statistics describe without disclosing personal identity. The Geography Division manages this geographic data in TIGER. TIGER is a nationwide database of streets and address ranges as well as other linear features and legal and statistical areas. It includes governmental unit boundary information for all legal areas in the United States.
Public extracts from the TIGER database supports academic research, individual and corporate decision making, and government operations from national to local levels. The major goals of TIGER/GML are to allow users to include TIGER data in their applications without the need to build area features from line segments or to translate the data from a proprietary format. The major goals of the WebTIGER application are to assess the use of TIGER/GML as an alternative to TIGER/Line, and to make TIGER map images and TIGER/GML encoded data available through the Geospatial One-Stop (GOS) as part of the National Spatial Data Infrastructure (NSDI) established by the Federal Geographic Data Committee (FGDC).
The WebBAS application provides local government users with a Web browser with an interactive standards-based capability to report changes to the boundaries of their governmental units online. Instead of responding to the Boundary and Annexation Survey (BAS) on paper survey forms and maps, the process will be done online. WebBAS combines a survey with GIS digitizing on the Web so that local government users can perform the entire update and review process in real-time over the Internet.
Managing and updating TIGER is a big job that involves not only Census Bureau staff, but also thousands of respondents in municipalities across the country. The BAS review and update procedures, until now, were paper-based surveys that consisted of multiple map sheets, forms, letters, postcards, and inserts. The major goals of the WebBAS application are to reduce the time spent by Census employees and local government offices to conduct the Boundary and Annexation Survey, to decrease errors, to increase the response rate, and to cut the cost of printing and mailing paper forms and maps. The WebBAS prototype solution not only provides users the ability to review and update textual data about their boundary information, such as the legal authorization for a boundary change; it also provides a Web-based transaction capability to immediately make updates to the boundary map delineations, such as adding in new land areas that now belong to a town.
The WebTIGER and WebBAS application demonstrations are the first steps in ground-breaking change for the Census Bureau and OGC. Because the functionality of these applications has been developed leveraging standards and standards based technologies, the Census Bureau can call upon any number of vendors to provide technology and need not restrict WebTIGER users or WebBAS participants to any specific technology. Equally important, the applications plug directly into other systems and portals that support OGC specifications, including GOS.
From an OGC perspective, this initiative allowed consortium members to validate the ability of applications developed according to adopted and developing OGC specifications for Web services to meet the interactive needs of the geospatial user community. Lessons learned from these prototype applications are being fed back into OGC's specification development processes.
Bob LaMacchia and Paul Daisey of the Census Bureau said: "TIGER/GML is intended to make TIGER data more accessible for public use because GML is XML, the leading data exchange encoding standard. The WebTIGER application lets users view or download just the TIGER data they need, and to combine it with map images and data from other GOS data providers, to answer questions and solve problems with a geographic component more rapidly and easily than before. The WebBAS application is focused on providing a time and cost efficient Electronic Government (eGov) alternative to paper maps and forms for local government participation in the BAS."
Anne Satterlee of the City of Fort Pierce, Florida was the first local tester of the on-line WebBAS application. She described the computer application as "a significant improvement over the conventional large paper survey." WebBAS," she continued will "save staff time, enhance accuracy and make the whole process easier." Satterlee was pleased to find no "bugs" in the prototype and suggested several software enhancements. She also felt that training should be provided to be sure all new users can take full advantage of the automated system. "Overall," she concluded, "this represents a major improvement in service for local government."
Jennifer Barmann Marcus of Northrop Grumman Information Technology, TASC said: "The Census Bureau is commended for taking bold steps to advance their mission and the NSDI by recognizing the benefit of the OGC Interoperability Program process to stimulate the geospatial community for standards based solutions to Census Bureau technical challenges. Each of the participating companies demonstrated their industry leadership throughout the project with a level of expertise and insight that was critical to moving forward on interoperability issues unique to the Census Bureau. During the initiative, the technical team applied multiple adopted and in process OpenGIS specifications to implement an unprecedented standards-based architecture to meet modernization goals of Census. Remaining true to the OGC IP Process, feedback on the application of GML in this initiative will help future updates of that specification. The architecture produced as part of this effort can be used to assure the interoperability of future Census Bureau procurements."
Source: OGC, Oct. 3, 2003