Winkel I

Parameters: Standard parallel

Classifications

pseudocylindric

Graticule

Meridians: Central meridian is a straight line 0.61 (or other value) as long as the equator. Other meridians are equally spaced sinusoidal curves, concave toward the central meridian.
Parallels: Equally spaced straight parallel lines. Perpendicular to the central meridian.
Poles: Lines 0.61 (or other value) as long as the equator.
Symmetry: About the central meridian or the equator.

Limiting forms

Eckert V, if the equator is the standard parallel.

Scale

True along latitudes 50°28′N and S. (or other chosen value).
Constant along any given latitude; same for the latitude of opposite sign.

Distortion

Not free of distortion at any point.

Origin

Developed by Oswald Winkel (1873-1953) of Germany in 1914 as the average of the sinusoidal and equirectangular projection in both x and y coordinates. When the standard parallels of the equirectangular projection are varied, the standard parallels and appearance of Winkel I vary. Use of latitudes 50°28′N and S. Results in a map at the correct total-area scale, but the local-area scale varies.

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.