A fast map-making preconditioner for regular scanning patterns

Abstract

High-resolution Maximum Likelihood map-making of the Cosmic Microwave Background is usually performed using Conjugate Gradients with a preconditioner that ignores noise correlations. We here present a new preconditioner that approximates the map noise covariance as circulant, and show that this results in a speedup of up to 400% for a realistic scanning pattern from the Atacama Cosmology Telescope. The improvement is especially large for polarized maps.

6 pages, 9 figures, accepted for publication in JCAP

References in corpus (4)

• Second Season QUIET Observations: Measurements of the CMB Polarization Power Spectrum at 95 GHz
• The Atacama Cosmology Telescope: Data Characterization and Map Making
• The First Public Release of South Pole Telescope Data: Maps of a 95-square-degree Field from 2008 Observations
• Making sky maps from Planck data

Cited by in corpus (3)

• The Atacama Cosmology Telescope: CMB Polarization at $200<\ell <9000$
• Cosmic Microwave Background Mapmaking with a Messenger Field
• Solving linear equations with messenger-field and conjugate gradients techniques - an application to CMB data analysis