Stereographic projection
Topic: Map Projections · NCERT: Class 11, Ch 4 "Map Projections"
Meaning
A stereographic projection is a perspective projection with the light source on the globe's surface. The light sits at the point directly opposite the point where the paper touches the globe. It shows the shapes of small areas correctly, which means it is conformal. Areas grow bigger away from the centre. It is commonly used for maps of the polar regions.
Example
A map of Antarctica made with the paper touching the South Pole and the light at the North Pole is a stereographic projection. The coastline near India's research stations, Maitri and Bharati, keeps its true local shape, though areas far from the pole appear somewhat enlarged.
Don't confuse with
- Gnomonic projection: here the light is at the centre of the globe, and great circles become straight lines.
- Orthographic projection: here the light is at infinity and the rays are parallel.