Central cylindrical projection

The central cylindrical projection with a 15° graticule, approximately to latitude ±72°. The distortion is noticeably worse than the Mercator projection.

The Central cylindrical projection is a cylindrical map projection. This is achieved by projecting, from the center of the Earth (hence perpendicularly to the surface), the Earth's surface onto a cylinder tangent to the equator. The cylinder is then cut along one of the projected meridians and unrolled into a flat map.[1]

The distortion in the regions beyond the equator is so pronounced (much worse than in the Mercator projection, which is sometimes erroneously presented as the central cylindrical)[2] that the central cylindrical is not frequently used as a practical projection.[1][2]

It is not known who first developed the projection, but it appeared with other new cylindrical projections in the 1800s, and regularly finds its way into textbooks (chiefly to illustrate that this is not the way Mercator is constructed).[1]

As with any cylindrical projection, the construction can be generalized by positioning the cylinder to be tangent to a great circle of the globe that is not the equator.[1]

Formula

\begin{align} x &= R( \lambda - \lambda_0), \qquad y &= R( \tan {\phi}) \end{align}

See also

References

  1. ↑ 1.0 1.1 1.2 1.3 Flattening the Earth: Two Thousand Years of Map Projections, John P. Snyder, Chicago University Press, 1993, pp. 106-107, ISBN 0-226-76747-7.
  2. ↑ 2.0 2.1 World Maps and Globes, Irving Fisher and O. M. Miller, Essential Books, 1944, p. 46.