We present a detailed description of the special procedures for calibration and quality assurance of Atacama Large Millimeter/submillimeter Array (ALMA) observations in Very Long Baseline Interferometry (VLBI) mode. These procedures are required to turn the phased ALMA array into a fully calibrated VLBI station. As an illustration of these methodologies, we present full-polarization observations carried out with ALMA as a phased array at 3mm (Band 3) and 1.3mm (Band 6) as part of Cycle-4. These are the first VLBI science observations conducted with ALMA and were obtained during a 2017 VLBI campaign in concert with other telescopes worldwide as part of the Global mm-VLBI Array (GMVA, April 1-3) and the Event Horizon Telescope (EHT, April 5-11) in ALMA Bands 3 and 6, respectively.
@article{arxiv.1901.09987,
title = {Calibration of ALMA as a phased array: ALMA observations during the 2017 VLBI campaign},
author = {Ciriaco Goddi and Ivan Marti-Vidal and Hugo Messias and Geoff Crew and Ruben Herrero-Illana and Violette Impellizzeri and Helge Rottmann and Jan Wagner and Ed Fomalont and Lynn D. Matthews and Dirk Petry and Neil Phillips and Remo Tilanus and Eric Villard and Lindy Blackburn and Michael Janßen and Maciek Wielgus},
journal= {arXiv preprint arXiv:1901.09987},
year = {2019}
}