The azimuthal equidistant projection, This projection is used by the USGS in the National Atlas for the United states Of America and for
large-scale mapping. In the case of radio, this projection allows for directional antenna aiming, especially in the case of HF communications. An operator can point the antenna, simply by
locating the target in the map and rotating the antenna to the angle indicated by the map. The map should be centred as nearly as possible to the actual antenna location.
While it may have been used by ancient Egyptians for star maps in some holy books, the earliest text describing the azimuthal equidistant projection is an 11th-century work by al-Biruni.