JCMT Newsletter No. 11 (Early Start)
 An Early Start to the Evening Shift
Studies over the past few months show that changing ambient temperature
effects on the antenna surface during the early evening can be
significantly reduced if the carousel is opened well in advance of the
commencement of observing. A closed building tends to exaggerate the
distortions to the surface and when the building is
finally opened. These effects persist well into evening shift, making
it necessary for more frequent pointing, focus and efficiency checks.
Therefore, wherever possible, the TSS will open the building early to
allow
the antenna to stabilise well in advance of the nominal 17:30 start of
evening shift. However, the daycrew leave the telescope at 16:00 sharp and
if nobody is remaining to buddy the TSS then the TSS must also leave. This
means that the building will be closed and the software systems run
down.
If would be extremely helpful, to both the TSS and to the observers, if
the evening shift observers at HP telephoned the TSS at no later than
15:30 to discuss the weather conditions, the state of the instruments and
thus make preliminary plans for their evening shift.
Observers can, if they want to get a good start, drive to the
telescope prior to the daycrew leaving
at 16:00. The TSS will be able to leave the carousel open and make
most, if not all, of the startup checks and tests (including the first run
through pointing, focus and calibration) well in advance of the 17:30
nominal shift start time.
If observers are not particularly worried about an early start then at
least the TSS is aware of this and can come down to HP for dinner without
having to immediately turn around and drive back up with observers. Or, as
is often the case, the TSS meets the observers on the way down to HP and
has to turn around and go up again, having just completely shut down the
carousel and the observing system.
Modification Author: Graeme Watt (gdw)
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