Simple conical projection with one standard parallel
Topic: Map Projections · NCERT: Class 11, Ch 4 "Map Projections"
Meaning
In this projection, a paper cone touches the globe along one parallel, called the standard parallel. The cone is then cut open and laid flat. The parallels become equally spaced arcs that share one centre. The meridians become straight lines that meet at the pole and cross the parallels at right angles. Scale is true along all meridians and along the standard parallel only. The pole is shown as an arc, not a point. The projection is neither equal area nor orthomorphic. It is useless for a world map because distortion is extreme in the other hemisphere.
Example
It suits mid-latitude areas that are narrow north-south but long east-west. Examples are the Narmada valley in central India, the Trans-Siberian Railway in Russia, the Canadian Pacific Railway and the USA-Canada boundary.
Don't confuse with
- Polyconic projection: this uses a separate cone for each parallel, not one cone. It is accurate near the central meridian of each sheet.
- Cylindrical projections: these suit the tropics and world maps, while conical ones suit mid-latitudes.