Quadrangle (cartography)
Quadrangle or shortly quad referred to in the mapping one type of card the United States Geological Survey (USGS). Quadrangle maps areprojected ontothe respective reference coordinate system (i.e. mapping of three-dimensional objects onto two-dimensional surfaces) so that the edges of the maps do not have to run at right angles or parallel to one another.
In the United States , 7.5 minute maps are common, covering areas from 130 to 180 km² (49 to 70 square miles). The individual cards are often named after a local physiographic feature. For example, the Ranger Creek Map is the map of an area in Texas where Ranger Creek flows.
The USGS square maps are also used to map planets and moons of the solar system. The planet Mars , for example, is mapped on 30 Mars charts , which are also named after the characteristics of the respective areas, see list of the degree fields on Mars . The maps of the two polar regions are not square, but circular.
Individual evidence
- ^ Ranger Creek Map (TX) yellowmaps.com