These data are identified by a three-character code indicating the type of information stored in each file. Geographic information is embedded in the TIFF data file in the form of descriptive tags. Translation and rotation are both 0. The last two lines are the UTM values of the upper left pixel of the data set. For example, when displayed using graphics arts software, the DRG is a simple picture on a computer screen.
Metadata are also important for establishing quality control.
Specific information can be extracted from metadata files and used to georeference the DRG depending on the requirements of individual raster viewing applications.