Aitoff

Aitoff refers to a type of pseudocylindrical, equal-area map projection. It was developed by Russian–American astronomer and geophysicist Argelander Aitoff in 1889. The Aitoff projection is a modification of the Hammer projection. It preserves area but distorts shape and distance. The central meridian is a straight line, while the equator and other parallels are arcs of ellipses. The shape of these ellipses is determined by a parameter that controls the projection's aspect ratio.

The Aitoff projection is primarily used for displaying global data, especially when preserving the relative sizes of landmasses is important. It is often used in cartography and astronomy for depicting the celestial sphere or planetary surfaces. Due to its equal-area nature, it avoids the significant area distortions found in many other projections, making it suitable for thematic maps showing distributions. However, like most equal-area projections, it introduces considerable shape distortion, particularly towards the edges of the map. This makes it less ideal for navigational charts or maps where accurate shapes and distances are paramount. The projection's visual appearance is characterized by its stretched poles and curved meridians and parallels, giving it a somewhat oval shape. It is a well-established projection within cartographic literature.