The Heterodyne Instrument for the Far Infrared (HIFI) on board the Herschel Space Observatory is composed of a set of fourteen double sideband mixers. We discuss the general problem of the sideband ratio (SBR) determination and the impact of an imbalanced sideband ratio on the line calibration in double sideband heterodyne receivers. The HIFI SBR is determined from a combination of data taken during pre-launch gas cell tests and in-flight. The results and some of the calibration artefacts discovered in the gas cell test data are presented here along with some examples of how these effects appear in science data taken in orbit.
@article{arxiv.1404.2806,
title = {The effect of sideband ratio on line intensity for Herschel/HIFI},
author = {Ronan Higgins and David Teyssier and Colin Borys and Jonathan Braine and Claudia Comito and Bertrand Delforge and Frank Helmich and Michael Olberg and Volker Ossenkopf and John Pearson and Russell Shipman},
journal= {arXiv preprint arXiv:1404.2806},
year = {2014}
}
Comments
21 pages, 10 figues. To be published in special Herschel calibration issue of Experimental Astronomy