EDP Sciences
Free access
Volume 417, Number 3, April III 2004
Page(s) 1189 - 1194
Section Instruments, observational techniques, and data processing
DOI http://dx.doi.org/10.1051/0004-6361:20034066

A&A 417, 1189-1194 (2004)
DOI: 10.1051/0004-6361:20034066

Noise power spectrum estimation and fast map making for CMB experiments

A. Amblard1, 2 and J.-Ch. Hamilton1, 3, 4

1  Physique Corpusculaire et Cosmologie, Collège de France, 11 pl. Marcelin Berthelot, 75231 Paris Cedex 05, France
2  University of California, Department of Astronomy, 601 Campbell Hall, Berkeley, CA 94720-3411, USA
    e-mail: amblard@in2p3.fr
3  Laboratoire de Physique Nucléaire et de Hautes Energies, 4, Place Jussieu, Tour 33, 75252 Paris Cedex 05, France
4  Laboratoire de Physique Subatomique et de Cosmologie, 53 Avenue des Martyrs, 38026 Grenoble Cedex, France

(Received 10 July 2003 / Accepted 27 December 2003 )

We present a method designed to estimate the noise power spectrum in the time domain for CMB experiments. The noise power spectrum is extracted from the time ordered data avoiding the contamination coming from sky signal and accounting the pixellisation of the signal and the projection of the noise when making intermediate sky projections. This method is simple to implement and relies on Monte-Carlo simulations, it runs on a simple desk computer. We also propose a trick for filtering data before making coadded maps in order to avoid ringing due to the presence of signal in the timelines. These algorithms were succesfully tested on Archeops data.

Key words: cosmic microwave background -- cosmology: observations -- large-scale structure of the Universe -- methods: numerical

Offprint request: J.-Ch. Hamilton, hamilton@in2p3.fr

© ESO 2004