rHEALPix

rHEALPix is a projection based on the HEALPix projection. The implementation of rHEALPix uses the HEALPix projection. The rHEALPix combines the peaks of the HEALPix into a square. The square's position can be translated and rotated across the x-axis which is a noval approach for the rHEALPix projection. The initial intention of using rHEALPix in the Spatial Computation Engine Science Collaboration Environment (SCENZGrid).

To run a inverse rHEALPix projection on a WGS84 ellipsoidal model, use the following command:

proj +proj=rhealpix -f '%.2f' -I +lon_0=0 +a=1 +ellps=WGS84 +npole=0 +spole=0 -E <<EOF
0 0.7853981633974483 
EOF
bash

Where `spole` and `npole` are integers from the range of 0 to 3 inclusive and represent the positions of the north polar and south polar squares.

Output of above command:

0 0.7853981633974483 0.00 41.94

See Also:  http://healpix.jpl.nasa.gov/