Gall's Stereographic Projection

A Cylindrical Projection which projects the equator onto a tangent cylinder which intersects the globe at ± 45°. The transformation equations are

$$x = \lambda$$

$$y = \tan({\textstyle{1\over 2}}\phi),$$

where $\lambda$ is the Longitude and $\phi$ the Latitude.

See also Stereographic Projection

References

Dana, P. H. ``Map Projections.'' http://www.utexas.edu/depts/grg/gcraft/notes/mapproj/mapproj.html.