Since February 2005, an Infrared Radiometer for Millimeter Astronomy (IRMA) has been measuring precipitable water vapour levels in Chile at the Gemini South site on Cerro Pachon with a second unit added at the Las Campanas observatories site in August 2005. We have also started data collection with three additional IRMA units at three locations for the TMT site testing effort. After a number of technical modifications to ensure reliable operations at much lower sites than IRMA was designed for, 6 months of near continuous pwv data have been collected at both existing telescope sites and several months of data at TMT candidate locations. These data are enabling us to compare the sites on diurnal as well as seasonal timescales.

Date Published: 27 June 2006
PDF: 10 pages
Proc. SPIE 6269, Ground-based and Airborne Instrumentation for Astronomy, 62695K (27 June 2006); doi: 10.1117/12.669508

Published in SPIE Proceedings Vol. 6269:
Ground-based and Airborne Instrumentation for Astronomy
Ian S. McLean; Masanori Iye, Editor(s)