This tool is a Windows 95/98/NT solution to the problem of adding GeoTIFF information that was omitted from TVA DRGs. Links for downloading the tool appear below.
Digital raster graphics (DRG) covering the United States are produced primarily by the United States Geological Survey (USGS). DRGs are raster images of ordinary USGS topographic maps, stored as TIFF raster files. The USGS produces DRGs of its 7.5-minute topos, its 1:100 000 scale topos, and its 1:250 000 scale topos.
DRGs for some areas of the United States are not produced by the USGS, however; they are produced by other agencies. DRGs for a large region of the southeastern U.S. are produced by the Tennessee Valley Authority (TVA).
If you use TVA-produced DRGs in GIS and mapping applications, you may already be aware that the TVA couldn't be bothered to add GeoTIFF information to its raster files like the USGS does with its DRGs. The TVA was kind enough, however, to provide world files (*.tfw) and metadata files (*.met). Many GIS applications can use the world files and/or metadata files, but some applications cannot properly georeference the DRG without GeoTIFF information included in the DRG.
From the links below, you can obtain a copy of the TVA DRG Repair Tool. The TVA DRG Repair Tool is a Windows-compatible program that combines a TVA-produced DRG with its companion world file and metadata file to create a new DRG that contains the GeoTIFF information required by many mapping and GIS applications.
The program is simple and straightforward and comes with a brief help file to guide you through the process.
Get the TVA DRG Repair Tool here.
The following errors have been noted in the program.
Your comments are welcome, as are questions about the TVA DRG Repair Tool. Feel free to use my contact form.
The previous edition of this document contains information on a process that can be performed on UNIX and other systems.
Last update: 01 Jan 2000 --