Theresa-Marie Rhyne
Lockheed Martin
U.S. EPA Scientific
Visualization Center
86 Alexander Drive
Research Triangle Park,
North Carolina 27711
Phone: (919) 541 - 0207
FAX: (919) 541 - 0056
Email: trhyne@vislab.epa.gov
Introduction:
Within five years, desktop visualization, geographic information systems, computational modeling and videoconferencing will converge to support local community decision making. Using the World Wide Web, digital library technologies, software agent mechanisms, and high speed networking, the general public will be able to access, retrieve, merge and analyze complex sets of spatial information and data. Affordable global positioning systems and mobile computing technologies will assist the rapid online collection of field data and real time analyses of specific community concerns. (1) Achievement of this dynamically linked cartographic data and visualization system by the year 2001 will require the acceptance of open spatial database standards. The spatial data infrastructure will also need to be merged with other evolving open systems environments.
The National Spatial Data Infrastructure:
There are a number of efforts underway to develop spatial data standards and infrastructure. Within the United States federal government, the Federal Geographic Data Committee (FGDC) is the major organization promoting the development of spatial dataset standards. The FGDC has advanced the development of the National Spatial Data Infrastructure (NSDI) for accessing and sharing spatial data. In April 1994, Executive Order 12906 was signed, directing all affected federal organizations to participate in establishing the NSDI. (2)
The Open Geographic Information System Consortium (OGS) is fostering the development of the Open Geodata Interoperability Specification (OGIS). More than thirty organizations, including geographic information systems, scientific visualization, and computer vendors, are participating in OGS. (3) Federal agencies and universities are supporting the project with considerable research activity. Implementation of the OGIS is referenced and intergrated into the 1994 plan for the National Spatial Data Infrastructure (NSDI).
There are also international efforts underway for a world wide spatial data infrastructure. The International Organization of Standardization (ISO) began addressing these issues in 1994 with a new ISO Technical Committee on Geographic Information /Geomatics.(4)
Merging 3D Graphics, WWW & Spatial Data Guidelines:
The computer graphics, World Wide Web, and mobile computing communities, respectively, are establishing guidelines for open systems. The OpenGL specification for computer graphics and the emerging Virtual Reality Modeling Language (VRML) for the WWW focus on three dimensional geometry parameters typically used in computer aided design. (5, 6) Commercial developers of the WWW are proposing the notion of browsers displacing existing operating systems as the access point to computing environments. This includes the establishment of open Internet scripting languages (e.g. Javascript and Telescript). (7,8) These languages will assist with the building of software agents that provide indirect management of information on the WWW. Issues associated with geographic registration, common data models, and the enormous size of spatial databases are not immediately addressed in these proposals. The National Spatial Data Infrastructure and the Open GIS Consortium are developing their guidelines in parallel to the rapidly evolving WWW community. To add even more complexity, the moblie computing community is examining routing and open protocol issues for data transmission via wireless networks. (9) We propose convergence of these various standards activities by the year 2001. Otherwise, the potential for spatial data roadblocks, software agent confusion, and graphical display congestion exists on the future global information highway.
Accessing Open Spatial Data at the US EPA:
At the United States Environmental Protection Agency (US EPA), efforts are underway to integrate the agency's geographic information systems, scientific visualization and WWW suite of tools for integrated environmental decision support by 2001. The EPA's National GIS Program Office is the focal point of EPA's efforts to implement a consistent Agency-wide spatial data management infrastructure. One result of these efforts is the EPA Spatial Data Library System (ESDLS) which accessible via the WWW. (10) ESDLS utilizes the Environmental Systems Research Institute's (ESRI) Arc/Info data management software (entitled Librarian) and complys with Spatial Data Transfer Standards. The ESDLS will be EPA's node on the FGDC's National Geospatial Data Clearinghouse.
During 1996, techniques for providing real time visualizations of spatial data sets from the ESDLS were explored. The EPA's Scientific Visualization Center, in collaboration with the agency's GIS support team, conducted initial evaluations of software that integrates visualization toolkits (e.g. Advanced Visual Systems (AVS)) and geographic information systems (e.g.ESRI's ArcInfo). (11) WWW user interfaces to GIS and Visualization file servers have also been successful implemented. Our future efforts will focus on providing effective two and three dimensional visual displays of ESDLS data sets that can support environmental decision making at the federal, state, and local community levels. Software agents will provide the necessary mechanisms for the transparent movement and conversion of spatial datasets into prescribed GIS, Scientific Visualization and WWW formats.
Concluding Remarks:
It is our hope that open spatial data standards will be supported and integrated into the future plans for computer graphics, WWW and mobile computing specifications. This will facilitate future cyberspace decision making activities that require geographic information and referencing.
Acknowledgements:
The EPA's Enterprise Technology Services Division and National GIS Program Office fostered the development of the ideas presented here. Thomas Fowler, Don Block and Tom Scheitlin of Lockheed Martin provided invaluable GIS technical viewpoints and support. Scott Sandall and others at AVS Inc. provided integrated software tools for the visualization of spatial datasets. Special thanks to Dudley Bromley (Lockheed Martin Manager for Visualization) and Lynne Petterson (EPA's Work Assignment Manager for Visualization).
References:
(1) Toomey, Christopher and William Mark, "Satellite Image Dissemination via Software Agents", IEEE Expert - Intelligent Systems & Their Applications, Vol 10, No. 5, Oct. 1995, pp. 44 - 51.
(2) Federal Geographic Data Committee (FGDC) (http://fgdc.er.usgs.gov/fgdc.html)
(3) The Open GIS Consortium (http://www.ogis.org/)
(4) Tom, Henry, "The Geographic Information Systems (GIS) Standards Infrastructure", StandardView, Association for Computing Machinery, Vol. 2, No. 3, September 1994, pp. 133 - 142.
(5) Segal, Mark and Kurt Akeley, "The OpenGL Graphics System: A Specification (Version 1.0), (http://www.sgi.com/Technology/openGL/glspec/glspec.html).
(6)The VRML 2.0 Specification (http://webspace.sgi.com/moving-worlds/)
(7) Java (tm): Programming for the Internet (http://java.sun.com/)
(8) Welcome to General Magic's Telescript Home Page (http://www.genmagic.com/Telescript/index.html)
(9) Kobb, Bennett Z., "Telecommunications" ( Technology 1995 - Analysis and Forecast Issue), IEEE Spectrum, Vol. 32, No. 1, Jan. 1995, pp. 30 - 34.
(10) The EPA Spatial Data Library System (ESDLS) (http://www.epa.gov/ngispr/esdls.html)
(11) The GIS - VIS Integration home page on the US EPA's public WWW server (http://www.epa.gov/gisvis)