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The largest (both in terms of scale and quantity) and best-known topographic series is the 7.5-minute, 1:24,000 scale, quadrangle, a non-metric scale virtually unique to the United States. Each of these maps covers an area bounded by two lines of latitude and two lines of longitude spaced 7.5 minutes apart.
A graphical or bar scale. A map would also usually give its scale numerically ("1:50,000", for instance, means that one cm on the map represents 50,000cm of real space, which is 500 meters) A bar scale with the nominal scale expressed as "1:600 000", meaning 1 cm on the map corresponds to 600,000 cm=6 km on the ground.
Map produced with DLG data. DLGs are normally derived from USGS maps or USGS map-related sources. DLGs are distributed at three different scales: large-scale, which normally correspond to the USGS 7.5- by 7.5-minute, 1:24,000 and 1:25,000-scale topographic quadrangle map series, 1:63,360-scale for Alaska and 1:30,000-scale for Puerto Rico; intermediate scale, which are derived from the USGS 30 ...
During the registration process, prospective volunteers submitted a list of the 7.5 minute quadrangle maps on which they wished to work. Once accepted into the project, volunteers received their assignment and 1:24,000 scale topographic map of their quad. While there was no deadline for completing maps, the project's administrators preferred ...
DOQs produced by the USGS cover an area measuring 7.5-minutes longitude by 7.5-minutes latitude (the same area covered by a USGS 1:24,000-scale topographic map, also known as a 7.5-minute quadrangle) or 3.75-minutes by 3.75-minutes.
In most European countries, the largest scale topographic map series is a 1:25.000 scale series. Notable exceptions are Austria (1:50,000) and Finland (1:20,000). Many non-European states limit the largest scale of their map series, usually to 1:50,000 scale, frequently due to the large size of the country covered (and hence for financial reasons).
The dataset primarily maps features a 1:24,000-scale, but in certain areas provides detail at 1:5,000-scale. A version of the NHD called the NHDPlus is integrated with elevation and other landscape data to create detailed drainage catchments and flow volume and velocity estimates for streams and rivers of the U.S. at 1:100,000-scale.
The USGS Topographic Map Names database (TMNDB [24] hereafter) was also 57 computer files containing the names of maps: 56 for 1:24000 scale USGS maps as with the NGNDB, the 57th being (rather than a second Alaska file) data from the 1:100000 and 1:250000 scale USGS maps. [25]