General

Used for regions along a great circle other than the equator or a meridian, with their general extent oblique to the equator. This can show the shortest distance between any two pre-selected points on the great circle as a straight line. Rhumb lines are curved.

Conformal but not perspective, equal area, or equidistant.

Graticule spacing increases away from the great circle but conformality is retained.

Both poles can be shown.

The equator and other parallels are complex curves concave toward the nearest pole.

Two meridians 180° apart are straight lines but all others are complex curves concave toward the great circle.

Directions

Reasonably accurate within 15° of the great circle.

Distortion increases with distance and is excessive toward the edges of a world map, except near the path of the great circle

Distances

True only along the great circle (line of tangency) or along two lines parallel to it.

Reasonably accurate only within 15° of the great circle.

Distortion increases with distance and is excessive toward the edges of a world map, except near the path of the great circle.

Areas

Reasonably accurate only within 15° of the great circle.

Distortion increases with distance and is excessive toward the edges of a world map, except near the path of the great circle

Shapes

Reasonably accurate only within 15° of the great circle.

Distortion increases with distance and is excessive toward the edges of a world map, except near the path of the great circle.

Type

Cylindrical.

Mathematically projected onto a cylinder tangent or secant along any great circle except the equator or a meridian.

History

Developed between 1900 and 1950 by Rosenmund, Laborde, Hotine et al.

Note

Directly supported.

(United States Geological Survey, n.d.)