Tobler hyperelliptical projection

The Tobler hyperelliptical projection is a family of pseudocylindrical projections used for mapping the earth.

It is named for Waldo R. Tobler, its inventor.

It is an equal-area projection. In the normal aspect, the parallels of latitude are parallel straight lines whose spacing is calculated to provide the equal-area property; the meridians of longitude (except for the central meridian, which is a straight line perpendicular to the lines representing parallels) are curves of the form "a|x|"^γ + "b|y|"^γ = 1 (with "a" dependent on longitude and "b" constant for a given map). When γ=2 the projection becomes the Mollweide projection; when γ=1 it becomes the Collignon projection; the limiting case as γ→infinity is the Cylindrical equal-area projection (Lambert cylindrical equal-area, Gall-Peters, or Behrmann projection). Values of γ that are favored by Tobler and others are generally greater than 2.

The projection was first described by Tobler in 1973.

External reference

cite journal
last=Tobler
first=Waldo
title=The hyperelliptical and other new pseudocylindrical equal area map projections
journal=Journal of Geophysical Research
volume=78
issue=11
pages=pp. 1753–1759
year=1973
doi=10.1029/JB078i011p01753