@inproceedings{7a2b21b6efcc40e1b92013625cc88e3b,
title = "Status of scientific commissioning of the Greenland Telescope",
abstract = "The Greenland Telescope (GLT), currently located at Thule Air Base, is a 12-m single dish telescope operating at frequencies of 86, 230 and 345 GHz. Since April 2018, the GLT has regularly participated in (sub-)mm VLBI observations of supermassive black holes as part of the Event Horizon Telescope (EHT) and the Global mm VLBI Array (GMVA). We present the status of scientific commissioning activities at the GLT, including most recently the 345 GHz first light and test observations. The antenna surface accuracy has been improved to ∼25 microns through panel adjustments aided by photogrammetry, significantly increasing the antenna efficiency. Through all-sky spectral line pointing observations (SiO masers at 86 GHz and CO at 230 and 345 GHz), we have improved the radio pointing accuracy down to <∼ 3{"}at all 3 frequencies. Due to the pandemic, we are in the process of transitioning GLT commissioning and observing activities to remote operations.",
keywords = "Commissioning, Greenland Telescope, Submillimeter-Wave, Supermassive black hole, Very Long Baseline Interferometry (VLBI)",
author = "Koay, {Jun Yi} and Satoki Matsushita and Keiichi Asada and Patel, {Nimesh A.} and Huang, {Chih Wei L.} and Geoffrey Bower and Chang, {Shu Hao} and Chen, {Ming Tang} and Chen, {Chung Cheng} and Ryan Chilson and Han, {Chih Chiang} and Ho, {Paul T.P.} and Huang, {Yau De} and Makoto Inoue and Homin Jiang and Koch, {Patrick M.} and Shoko Koyama and Kuo, {Cheng Yu} and Derek Kubo and Li, {Chao Te} and Liu, {Ching Tang} and Liu, {Kuan Yu} and Lo, {Wen Ping} and Pierre Martin-Cocher and Masanori Nakamura and Norton, {Timothy J.} and George Nystrom and Peter Oshiro and Jongho Park and Pu, {Hung Yi} and Philippe Raffin and Ramprasad Rao and Cristina Romero-Ca{\~n}izales and Paul Shaw and Sridharan, {Tirupati K.} and Ranjani Srinivasan and Wei, {Ta Shun} and Yu, {Chen Yu}",
note = "Funding Information: The GLT project is a collaboration between ASIAA and the Smithsonian Astrophysical Observatory (SAO). Taiwan{\textquoteright}s participation in the GLT is supported by Academia Sinica as well as the Ministry of Science and Technology (MOST) of Taiwan (projects MOST 99-2119-M-001-001-MY4, MOST 103-2119-M-001-010-MY2, MOST 106-2119-M-001-013, MOST 108-2112-M-001-048, MOST 109-2124-M-001-005) through Taiwan{\textquoteright}s participation in the ALMA-NA project; the realization of the GLT provides a unique North-South baseline for ALMA{\textquoteright}s VLBI capability. The GLT project team thanks the strong support from the National Chun-Shan Institute of Science and Technology. We also thank NRAO and MIT Haystack Observatory for their support in the initial acquisition of the ALMA-NA prototype antenna which was repurposed as the GLT. We thank the NAOJ for their support of the GLT receiver instrumentation. The GLT team appreciates the development work provided by Vertex Antennentechnik GmbH and ADS international. We also thank Atunas outdoor gear in Taiwan for providing the arctic gear necessary for our work in Greenland. This project would not have been possible without the United States Air Force 821st Air Base Group in Thule Air Base, Greenland, who have granted us the use of their site and access to their base facilities and logistics chain. Finally, the transition to remote operations would not have been possible without the support and help provided by the local staff at Thule Air Base, in particular Claus Gonssen and Susan Iversen. Publisher Copyright: {\textcopyright} COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.; Ground-Based and Airborne Telescopes VIII 2020 ; Conference date: 14-12-2020 Through 22-12-2020",
year = "2020",
doi = "10.1117/12.2561491",
language = "English",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Marshall, {Heather K.} and Jason Spyromilio and Tomonori Usuda",
booktitle = "Ground-Based and Airborne Telescopes VIII",
}