The DOQQGrid layer is a variation of the NC24Quads layer (USGS 1:24,000 scale quadrangles). The grids resulted from the splitting of the NC24Quads into equal quadrants.
REQUIRED: A summary of the intentions with which the data set was developed.
REQUIRED: The basis on which the time period of content information is determined.
REQUIRED: Restrictions and legal prerequisites for using the data set after access is granted.
Internal feature number.