Central Meridian: Straight line 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 half as long as the Equator.
Symmetry: About the central meridian or the Equator.
This projection is an arithmetic average of the x and y coordinates of the Sinusoidal and Plate Carrée projections. Scale is true along latitudes 37º55'N and S, and is constant along any parallel and between any pair of parallels equidistant from the Equator. There is no point free of all distortion, but the Equator is free of angular distortion. This projection is not equal-area, conformal, or equidistant.