Normal projection
Also called: Equatorial projection · Topic: Map Projections · NCERT: Class 11, Ch 4 "Map Projections"
Meaning
A normal projection is one in which the developable surface touches the globe at the equator. It is also called an equatorial projection. The name comes from where the tangent, the line or point of contact, lies. For a cylinder, this is the usual position: parallels and meridians come out as straight lines at right angles. Scale is truest near the equator and gets worse towards the poles.
Example
Mercator's projection is a normal cylindrical projection, with the cylinder touching the globe along the equator. Places near the equator, such as Indonesia, look close to their true size. Greenland, far to the north, looks hugely enlarged.
Don't confuse with
- Polar projection: here the surface touches the globe at a pole, not at the equator.
- Oblique projection: here the surface touches the globe somewhere between the pole and the equator.
Related concepts
- Developable surface
- Non-developable surface
- Cylindrical projection
- Conical projection
- Zenithal projection
- Oblique projection
- Polar projection