THE UNITED KINGDOM INFRARED TELESCOPE
ANNUAL REPORT
1998

3. Report on Operations

3.1. Summary

• UKIRT's instruments operated with great reliability, enabling observers to take full advantage of the excellent observing weather; semester 98A saw a record for the highest ever usage of science time with a fault loss of only 2.5%.
• The realuminization of the primary mirror in late May and early June 1998 was ultimately successful, though two attempts were required before a sufficiently thick coating was deposited on the glass.
• ORAC development continued apace, with successful collaboration between the UK ATC and Gemini on adopting the Gemini OT for UKIRT, and ORAC-DR being successfully used for UFTI data reduction.
• The silver/dielectric dichroic was shown to have degraded. After a spare dichroic of the new type was installed, the overall telescope emissivity was measured at around 11%. Some of this is due to the thicker struts of the new top end.
• UKIRT's image quality was extremely impressive. By September 1998 there were times when IRCAM's relatively coarse pixel scale was severely undersampling the images of point sources.
• UFTI arrived, was installed and commissioned late in 1998, and by early 1999 was producing excellent imaging. UFTI continues the trend toward smaller pixel sizes driven by the telescope's improved image quality.
• At the same time, ORAC-DR was installed and provides a state-of-the-art data reduction pipeline for UFTI data. The speed of the pipeline was initially bound by the available computer speed, a situation rectified by the purchase in Spring 1999 of a more powerful Sun workstation for the summit. The quality of ORAC data reduction is already clearly superior to that produced by IRCAMDR.
• Upgrades systems continued to work extremely effectively, and various software enhancements made them more straightforward to use.
• In November, the Institute of Astronomy at the University of Cambridge offered to provide a UKIRT archive mirror site and de-archiving services. This generous offer was gratefully accepted.
• A recurring theme of reports filed by visiting observers was that the support afforded by UKIRT staff in 1998 was of the highest quality.