A wavelet analysis of CMB time-ordered data applied to Archeops

¹ Laboratoire de Physique Subatomique et Cosmologie, 53 avenue des Martyrs, 38026 Grenoble Cedex, France e-mail: macias@lpsc.in2p3.fr
² Laboratoire de l'Accélérateur Linéaire BP 34, Campus Orsay, 91898 Orsay Cedex, France e-mail: bourrach@lal.in2p3.fr

Received: 3 November 2005
Accepted: 3 April 2006

Abstract

We present an alternative analysis of CMB time-ordered data (TOD) using a wavelet-based representation of the data time-frequency plane. We demonstrate that the wavelet transform decorrelates -type Gaussian stationary noise and permits a simple and functional description of locally stationary processes. In particular, this makes it possible to generalize the classical algorithms of map making and CMB power-spectrum estimation to the case of locally stationary  type noise. As an example, we present a wavelet-based algorithm for the destriping of CMB-like maps. In addition, we describe a wavelet-based analysis of the Archeops data including time-frequency visualization, wavelet destriping, and filtering of the TOD. These filtered data were used to produce polarized maps of Galactic dust diffuse emission. Finally, we describe the modeling of the non-stationarity on the Archeops noise for estimating the CMB power spectrum.