MOC - HEALPix Multi-Order Coverage map Version 1.0

Understand

This document describes the Multi-Order Coverage map method (MOC) to specify arbitrary sky regions.

• The goal is to be able to provide a very fast comparison mechanism between coverage maps.
• The mechanism is based on the HEALPix sky tessellation algorithm.
• It is essentially a simple way to map regions of the sky into hierarchically grouped predefined cells.