Journal Article

Phase shift sequences for an adding interferometer

Peter Hyland, Brent Follin and Emory F. Bunn

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 393, issue 2, pages 531-537
Published in print February 2009 | ISSN: 0035-8711
Published online February 2009 | e-ISSN: 1365-2966 | DOI:
Phase shift sequences for an adding interferometer

Show Summary Details


Cosmic microwave background (CMB) polarimetry has the potential to provide revolutionary advances in cosmology. Future experiments to detect the very weak B-mode signal in CMB polarization maps will require unprecedented sensitivity and control of systematic errors. Bolometric interferometry may provide a way to achieve these goals. In a bolometric interferometer (or other adding interferometer), phase shift sequences are applied to the inputs in order to recover the visibilities. Noise is minimized when the phase shift sequences corresponding to all visibilities are orthogonal. We present a systematic method for finding sequences that produce this orthogonality, approximately minimizing both the length of the time sequence and the number of discrete phase shift values required. When some baselines are geometrically equivalent, we can choose sequences that read out those baselines simultaneously, which has been shown to improve the signal-to-noise ratio.

Keywords: techniques: interferometric; techniques: polarimetric; cosmic microwave background

Journal Article.  5711 words.  Illustrated.

Subjects: Astronomy and Astrophysics

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