Development of Digital Aerial Photography Archives for the Greater Everglades of South Florida
Peter R. Briere
DynCorp Systems and Solutions LLC, Gainesville, FL
Thomas J. Smith III
U.S. Geological Survey, St. Petersburg, FL
Ann M. Foster
U.S. Geological Survey, Gainesville, FL
Alisa W. Coffin
University of Florida, Gainesville, FL
Ken Rutchey
South Florida Water Management District, West Palm Beach, FL
John W. Jones and Carson Van Arsdall
U.S. Geological Survey, Reston, VA
William B. Perry
National Park Service, Homestead, FL
Currently a restoration effort, guided by the Comprehensive Everglades Restoration Plan (CERP), is underway in central and southern Florida. A basis for the restoration must be a clear understanding of pre-management wetland characteristics in order to establish a gauge for future performance and impacts of CERP. An increase in studies related to pre-management wetland characteristics has resulted in an increased demand for historical data from the Greater Everglades region. Aerial photographs provide one form of historical data documenting past effects of flood protection and water supply management measures on south Florida ecosystems.
More than 25,000 historical aerial photographs of the Everglades and South Florida, some flown as early as the mid 1920’s, are known to currently exist in print or negative form at various locations. This estimate only includes photographs whose physical location is known and accessible, many of which are temporarily situated at the USGS Gainesville facility. The USGS Florida Integrated Science Center (FISC), in collaboration with USGS Eastern Region Geography, processed some of these photographs in 2001 and 2002 (see fig.1). The primary goals of this project were to 1) catalog available photographs in a database 2) convert these print and negatives to digital form 3) make the digital files readily accessible via publication and 4) orthorectify the files for future spatial data analyses.
Figure 1. Example of 1940 Rectified Imagery, South Florida and Florida Bay
To date this effort has produced one USGS Open-File Report on CD-ROM with rectified 1927 topographic sheets (t-sheets). Other Open-File Reports containing digital files of 1940 and 1987 aerial photography are currently in review. Another report with 1964 aerial photography is being prepared. Over 8,000 entries have been added to the database, documenting quality and quantity of available photographs. More than 2,000 photographs have been scanned at 800 dots per inch (dpi) or close to 31.75 microns. Thousands more photos have been scanned at 300 dpi to generate mosaics that establish flight information. The mosaics and flight lines will also facilitate future orthorectification and are used for publication purposes.
Another related product resulted from the conversion of 820 digital ortho quarter quads (DOQQs) to 54 south Florida basemaps extending from Lake Okeechobee to Florida Bay. These basemaps are 2-meter resolution mosaics in contrast to the 1-meter DOQQs. Using 2m basemaps makes storage and retrieval more efficient compared to the DOQQs, and thus reduces the time necessary for orthorectification. Each basemap is a mosaic of 8-16 DOQQs derived from aerial photography flown in 1994.
The aerial photographs converted to digital files and published so far represent a segment of the existing prints and negatives available. Many aerial flights covered portions of the south Florida area and these photographs remain in analog form. A small technical staff of 1-3 may require 4-12 years of full-time effort to convert the remaining photographs to orthorectified and published form given current available hardware and software capabilities. This assumes future storage needs
will be accounted for. An associated project will make all the digital images and linked attribute databases available via the internet.
Contact: Peter Briere, DynCorp Systems and Solutions LLC, 412 NE 16th Ave., Room 250, Gainesville, FL 32601, Phone: 352-372-2571x26, Fax: 352-374-8080, Email: , Poster, Information Systems