Report to the JCMT Board - April 2000

Since the last report, the acquisition of inclinometry (measures of the track profile) has remained infrequent (typically a few weeks), in order to spare the two surviving carousel drives from excessive load. As also reported last time, the profile remains very stable on these timescales - a tribute to the solution to the underloading detected and corrected in the previous semester. Following the carousel drive refurbishment in March the frequency of inclinometry data-taking may return to previous levels : weekly or so.

Pointing generally remains accurate to approximately 1.5" rms in each coordinate. A 3 hour-long experiment in late December tracking a source over 100 degrees of azimuth through transit in the south showed azimuth tracking errors of 0.7" rms. The performance in elevation was marred by a sudden 4" shift near transit, a phenomenon that seems persistent and is currently under investigation. Like most observations in this period, most pointing data has been taken with SCUBA.

An updated (RJ2000) pointing catalog was tested and installed on 16 Nov 1999.

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