Hammer retroazimuthal back hemisphere
Parameters: Latitude of origin
Geocart menu class: Azimuthal
Geocart family: Retroazimuthal
Neither conformal nor equal area
Meridians: Central meridian is straight. Other meridians are curved.
Poles: Curved lines
Symmetry: About the central meridian
Extreme distortion of area and shape
The direction from any point to the center of the map is the angle that a straight line connecting the two points makes with a vertical line. This feature is the basis of the term "retroazimuthal." Scimitar-shaped boundary. Considerable overlapping when the entire sphere is shown.
To determine the direction of a central point from a given location
Presented by H.H. Ernst von Hammer (1858–1925) of Germany in 1910. Independently presented by Edward A. Reeves (1862–1945) and Arthur R. Hinks (1874–1945) of England in 1929.
Craig Retroazimuthal has straight, equally spaced meridians.
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.