The HEALPix Primer
HEALPix is a Hierarchical, Equal Area, and iso-Latitude Pixelation
of the sphere designed to support efficiently
(1) local operations on the pixel set,
(2) a hierarchical tree structure for multi-resolution applications, and
(3) the global Fast Spherical Harmonic transform.
HEALPix based mathematical software meets the challenges
which future high resolution and large volume CMB data sets,
including the WMAP and Planck mission products, will present.
Krzysztof M. Górski, Benjamin D. Wandelt, Eric Hivon, Frode K. Hansen,
and Anthony J. Banday
Revision: Version 3.11; April 24, 2013
http://healpix.sf.net
Version 3.11, 2013-04-24