Azimuthal equidistant projection
Topic: Map Projections · NCERT: Beyond NCERT
Meaning
An azimuthal equidistant projection is a zenithal projection. That means a flat plane touches the globe at one point, and that point becomes the centre of the map. From this centre, both distance and direction to every other point are true. Distances and directions between two points that are not the centre are not true. This makes it useful for planning air routes and radio links from one city.
Example
A map of this kind centred on Delhi lets you read the straight-line distance and direction from Delhi to any world capital. A version centred on the North Pole forms the emblem of the United Nations.
Don't confuse with
- Equidistant projection: this is the general class. It keeps true scale only along certain chosen lines. The azimuthal equidistant keeps true distance along every line that starts from the centre point.
- Gnomonic projection: this is also a zenithal projection, but it shows every great circle as a straight line. It does not keep distances true.