Geocart menu class: Lenticular
Neither conformal nor equal area
Meridians: Central meridian is straight. Other meridians are curved, equally spaced along the Equator and concave toward the central meridian.
Parallels: Equator and the poles are straight. Other parallels are curved, equally spaced along the central meridian and concave toward the nearest pole.
Poles: Straight lines about 0.4 as long as the Equator, depending on the latitude of the standard parallels of the base Equidistant Cylindrical projection
Symmetry: About the central meridian or the Equator
True along the central meridian. Constant along the Equator.
Moderate except near outer meridians in polar regions
Equally spaced central meridian and Equator
Presented by Oswald Winkel (1873-1953) of Germany in 1921. Obtained by averaging coordinates of Equidistant Cylindrical and Aitoff (not Hammer-Aitoff) projections. Winkel applied the name “Tripel”, normally meaning triple.
Description adapted from J.P. Snyder and P.M. Voxland, An Album of Map Projections, U.S. Geological Survey Professional Paper 1453. United States Government Printing Office: 1989.