by Sheena K. Beaverson and Robert J. Krumm
State and federal agencies with interests in Illinois entered into a joint funding agreement with the United State Geological Survey (USGS) to purchase a full set of Digital Orthophoto quarter Quadrangles (DOQ) for the state of Illinois, at a cost of 3.4 million dollars. DOQs are based on aerial photography that is registered to map coordinates. Illinois DOQs are the most comprehensive, up-to-date, large-scale geographic base data available for the state. They are well suited for virtually any mapping project.
DOQ data has been generated by the USGS National Aerial Photography Program (NAPP) Three DOQ program; NAPP III aerial photography was flown during the years of 1998 through 2001. The DOQ data set comprises 210 gigabytes of uncompressed data, or 11 to 44 gigabytes after compression. Very few organizations would have been able to access or obtain the datain its original format. The only practical way to serve the data proved to be as compressed files online, free of charge through the Illinois Natural Resources Geospatial Data Clearinghouse (Illinois Clearinghouse). Support was provided for the file processing necessary to archive and distribute 4,173 DOQ files for the state of Illinois.
DOQ data were first made available online in June, 2000. There were initially 200 files available. By June of 2001, 2,891 DOQs had been delivered from the USGS and made available online at the Illinois Clearinghouse. Web site visitors downloaded about 44,450 DOQ files, about 98 gigabytes of data, during that time period. Statewide coverage was completed in February, 2002. During the second year of the data availability (June 1, 2001 through May 30, 2002) over 180,600 DOQ files, about 417 gigbytes of data, had been downloaded by web site visitors. The DOQ data layer continues to be popular. In recent months, an average of 480 DOQ files have been downloaded per day.
The DOQ ArcIMS interactive Map Service was made public in June, 2001. This Map Service was named a 3rd place winner ofthe 2001 Geography Network Challenge sponsored by ESRI and National Geographic. The DOQ Web Project staff earned the Illinois State Geological Survey Outstanding Team Award for 2001. Additionally, Illinois was ranked as a 2001 Digital State Survey 2nd Place Winner, in the GIS/Transportation Category. Data distribution efforts by the Illinois Clearinghouse were favorably cited in press releases from the office of the Governor in association with this award.
DOQ data are useful to county and local governments, the private sector (consultants, contractors, developers, etc.) in many disciplines, including agricultural and environmental organizations, university students and faculty, state and federal agencies, and the general public. As an excellent geographic base data layer, DOQs may be used for large-scale mapping projects in crop science, agriculture, environmental assessment, urban planning, geology, soils science, watershed management, geography, landscape architecture, civil engineering, and biology. Economically, access to DOQs enables professionals to more readily develop projects to foster sustainable use of natural resources and increases scientists' capacity to address changing world food and agricultural demands.
The Illinois Clearinghouse and the DOQ project were promoted at multiple meetings and conferences including: the 2001 University of Illinois Environmental Horizons event in Champaign, Illinois, multiple meetings of the Illinois GIS Association (ILGISA) trhoughout the state, the North Central Section Geological Society of America (NC-GSA) meeting in Bloomington, Illinois, the Digital Mapping Techniques 2001 annual meeting in Tuscaloosa, Alabama, the National States Geographic Information Council 2001 annual meeting in St. Louis, Missouri, the GSA 2001 annual meeting in Boston, Massachusetts, GIS Day on November 15, 2001 at the Illinois State Capitol building in Springfield, Illinois, and the 2002 AmericaView meetings in Cleveland, Ohio and Sioux Falls, South Dakota.
Sheena K. Beaverson
GIS Specialist and Assistant Systems Programmer
Illinois State Geological Survey
615 East Peabody Drive
Champaign, Illinois 61821