@article{b7131970bb2344d5b879de051ecf9210,
title = "Inverse Multiview. I. Multicalibrator Inverse Phase Referencing for Microarcsecond Very Long Baseline Interferometry Astrometry",
abstract = "Very Long Baseline Interferometry (VLBI) astrometry is a well established technique for achieving ±10 μas parallax accuracies at frequencies well above 10 GHz. At lower frequencies, uncompensated interferometer delays associated with the ionosphere play the dominant role in limiting the astrometric accuracy. Multiview is a novel VLBI calibration method, which uses observations of multiple quasars to accurately model and remove time-variable, directional-dependent changes to the interferometer delay. Here we extend the Multiview technique by phase-referencing data to the target source ({"}inverse Multiview{"}) and test its performance. Multiple observations with a four-antenna VLBI array operating at 8.3 GHz show single-epoch astrometric accuracies near 20 μas for target-reference quasar separations up to about 7°. This represents an improvement in astrometric accuracy by up to an order of magnitude compared to standard phase-referencing. ",
author = "Hyland, {L. J.} and Reid, {M. J.} and Ellingsen, {S. P.} and Rioja, {M. J.} and R. Dodson and G. Orosz and Masson, {C. R.} and Mccallum, {J. M.}",
note = "Funding Information: This research was supported by the Australian Research Council (ARC) Discovery Grant DP180101061. We want to thank Mr Brett Reid and Dr Warren Hankey for helping maintain and organizing all University of Tasmania radio telescopes and Mrs Beverly Benson for managing the Ceduna 30 m radio telescope. We thank the anonymous referee for helpful comments and suggestions that improved the paper. We acknowledge the Amangu, Jawoyn, Paredarerme, and Wiriangu peoples as the traditional owners of the land situating the Yarragadee, Katherine, Hobart, and Ceduna telescopes respectively. This research has made use of NASA's Astrophysics Data System Abstract Service. This research made use of Astropy, a community-developed core Python package for Astronomy (Astropy Collaboration et al. , ). Publisher Copyright: {\textcopyright} 2022. The Author(s).",
year = "2022",
month = jun,
day = "1",
doi = "10.3847/1538-4357/ac6d5b",
language = "English",
volume = "932",
journal = "The Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing",
number = "1",
}