This page contains some details of the igloo pixelization, proposed for use in the Planck project. We focus on these pixelizations because they are maximally azimuthal, and can be made with pixels that are hierarchical and equal area. They also have the advantage that the pixels can be exactly integrated over very quickly.

We investigate two basic schemes: one with only twelve base pixels and one with 12,000. The twelve pixel base scheme (3:6:3) is simpler, but has pixels which are more distorted than if there are more base pixels. The 12,000 base pixel scheme has very uniform pixels which are all very nearly square, which is an advantage when trying to invert the maps.

The software has just been released and at present has only been completed for the 3:6:3 equal latitude pixelization. However, much of it can be used for any given igloo pixelization. Let us know if you have difficulty using it or suggestions for improving it.


Direct questions to Robert Crittenden or Neil Turok.