Hammer retroazimuthal projection
The front hemisphere of the Hammer retroazimuthal projection. 15° graticule; center point at 45°N, 90°W.
The back hemisphere of the Hammer retroazimuthal projection. 15° graticule; center point at 45°N, 90°W.
The Hammer retroazimuthal projection is a modified azimuthal proposed by Ernst Hermann Heinrich Hammer in 1910. As a retroazimuthal projection, azimuths (directions) are correct from any point to the designated center point.[1] Additionally, all distances from the center of the map are proportional to what they are on the globe. In whole-world presentation, the back and front hemispheres overlap, making the projection a non-injective function. Given a radius R for the projecting globe, the projection is defined as:
where
and
The latitude and longitude of the point to be plotted are φ and λ respectively, and the center point to which all azimuths are to be correct is given as φ1 and λ0.
See also
References
- ↑ Snyder, John P. (1993). Flattening the Earth: Two Thousand Years of Map Projections. Chicago: University of Chicago Press. pp. 228–229. ISBN 0-226-76747-7. Retrieved 2011-11-14.
External links
- Description of Hammer Retroazimuthal front hemisphere.
- Description of Hammer Retroazimuthal back hemisphere.
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