HAL : in2p3-00285456, version 1
 arXiv : 0806.0380
 Code Bibliographique ADS : 2009A&A...497..963C
 Astronomy and Astrophysics 497 (2009) 963-971
 An efficient phase-shifting scheme for bolometric additive interferometry
 R. Charlassier1, J.-C. Hamilton1, É. Bréelle1, A. Ghribi1, Y. Giraud-Héraud1, J. Kaplan1, M. Piat1, D. Prêle1
 (2009)
 Context: Most upcoming CMB polarization experiments will use direct imaging to search for the primordial gravitational waves through the B-modes. Bolometric interferometry is an appealing alternative to direct imaging that combines the advantages of interferometry in terms of systematic effects handling and those of bolometric detectors in terms of sensitivity. Aims: We calculate the signal from a bolometric interferometer in order to investigate its sensitivity to the Stokes parameters paying particular attention to the choice of the phase-shifting scheme applied to the input channels in order to modulate the signal. Methods: The signal is expressed as a linear combination of the Stokes parameter visibilities whose coefficients are functions of the phase-shifts. Results: We show that the signal to noise ratio on the reconstructed visibilities can be maximized provided the fact that the phase-shifting scheme is chosen in a particular way called coherent summation of equivalent baselines. As a result, a bolometric interferometer is competitive with an imager having the same number of horns, but only if the coherent summation of equivalent baselines is performed. We confirm our calculations using a Monte-Carlo simulation. We also discuss the impact of the uncertainties on the relative calibration between bolometers and propose a way to avoid this systematic effect.
 équipe(s) de recherche : APC - Cosmologie et Gravitation
 Thème(s) : Physique/Astrophysique/Cosmologie et astrophysique extra-galactiquePlanète et Univers/Astrophysique/Cosmologie et astrophysique extra-galactique
 Lien vers le texte intégral : http://fr.arXiv.org/abs/0806.0380
 in2p3-00285456, version 1 http://hal.in2p3.fr/in2p3-00285456 oai:hal.in2p3.fr:in2p3-00285456 Contributeur : Simone Lantz <> Soumis le : Jeudi 5 Juin 2008, 15:33:26 Dernière modification le : Samedi 9 Juin 2012, 18:33:16