[OSRS-PROJ] Quadrilatieralized Spherical Cube projection

[Dan Stahlke]

I need to efficiently (with low distortion) divide the globe into  
square tiles in order to store global images.  I am currently using a  
modified gnomonic projection onto a cube.  The projection I am  
currently using is an arctangent of the gnomonic projection (which  
could also be visualized as two cylindrical projections, one for each  
axis).  I am using a modified version of GCTP for this, but Proj.4  
looks a lot better.  There doesn't seem to be any existing projection  
similar to what I am using, but in the course of my research I found  
out about the Quadrilatieralized Spherical Cube projection, which  
sounds a lot better.

This projection is used by the COBE project to store images of the sky.   
It is a projection of the sphere onto a cube and is supposed to have  
distortion of less than 1%.

It looks like the Quadrilatieralized Spherical Cube projection doesn't  
currently exist in Proj.4, but if needed I am willing to add it.  My  
question is: does this projection already exist under a different name,  
or is there something else that can be used?  If I add this projection,  
could it be included with the main distribution?

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