Central Meridian: Straight line at least half as long as the Equator.
Other Meridians: Equally spaced sinusoidal curves concave toward the central meridian.
Parallels: Equally spaced straight parallel lines, perpendicular to the central meridian.
Poles: Lines at least half as long as the Equator.
Symmetry: About the central meridian or the Equator.
This projection is an arimethical average of the x and y coordinates of the Sinusoidal and Equidistant Cylindrical projections. Scale is true along the standard parallels and is constant along any parallel and between any pair of parallels equidistant from the Equator. There is no point free of distortion. This projection is not equal-area, conformal, or equidistant.
For this projection, only one standard parallel is specified. The other standard parallel is the same latitude with the opposite sign. Any latitude may be chosen; the default is set to 50º28'.
This projection was developed by Oswald Winkel in 1914. Its limiting form is the Eckert V when a standard parallel of 0º is chosen.