UKIDSS Observer notes
|UKIRT Infrared Deep Sky Survey Observer
These notes are intended solely for UKIDSS Observers coming to the
Procedures are more or less the same as for visiting observers on
Cassegrain proposals and PATT. However here we gather together the
You should arrange to arrive at the JAC offices by mid-morning on the
day before your first observing night. This gives time for a discussion
with your support astronomer of any issues you need to be aware of
(instrument status, the various queues etc.) the link to the left takes
you to the JAC visitor information page.
The JAC reservation request form must be sent to JAC by each
observer planning to attend the observing run. Please complete ALL
sections - your arrival time in Hilo is important so that we can
schedule your travel between JAC and the Mauna Kea Residence. If you
encounter any problems with this form, please fax this text form.
For Proposal Number, enter UKIDSS. For Principal Investigator, enter A
You will be given a safety briefing by your support astronomer. In
advance, please read the specific section of the JAC safety manual
linked to at the left. Your support astronomer will be your associated
These sections detail
summit operation of the surveys and assume that you have read the basic
online documents (Operational Model, execution tools documentation, OMP
Startup and shutdown of WFCAM are both described in the RUNUP page. You should be
familiar with this before you get to the summit.
In the QT, select Semester UKIDSS, Instrument WFCAM, set the seeing and
sky brightness. Click Search
and select MSBs
from the top of the resulting queue. Make sure you read the observer
notes in the MSB. All other execution is as stated in the UKIRT
Preparation and Execution documents.
See the WHAT'S
ON TONIGHT PAGE for priorities.
The TSS is responsible for ensuring that the nights' data are entirely
calibratable. This includes taking observations of dawn twilight
flats on selected nights,
and dark frames at an appropriate frequency. These calibrations are
mandatory and the TSS will carry them out interspersed with the survey
The UKIDSS surveys are set by the JAC and UKIDSS Survey heads. In all
cases the TAG priority (the integer part in the priority column)
is initially 50. TAG adjustment may be used by the UKIRT survey support
scientist to selectively
enhance the completion of a survey found to be falling behind (this
will be obvious in the integer part of the priority column entry). The
decimal part is set by the internal priority per msb, which is
generally as set initially by the survey head, but may be varied by JAC
if particular MSBs are considered to be important to complete.
Observers are asked not to
ignore MSBs at the top of the queue if they are (for example) badly
placed/setting; if this is the case, the priority may have been set
high in order that the survey does not miss its chance at getting those
particular MSBs. Note that instructions in the Tonight page are more
frequently updated and should be taken to override anything written
here, in cases of discrepancy.
Please ensure that you make use of the following three levels of night
- Shift log comments - these are displayed at the top of the OMP
night log and should be used for "top level" statements of progress -
e.g. sky conditions, project switches etc.
- Obs log comments - these are interspersed with frames in the
detailed observation listing at the end of the log and should be used
to comment on properties of individual frames (e.g. when flagging a
frame as bad, please make a note of why it is).
- accept/reject - when you complete an MSB, a dialogue box pops up
which asks you to accept or reject the data taken. It includes a text
box; please use this to describe the result of running the MSB, even if
it's to say that there is no evidence of any problem.
It is not easy to give hard and fast rules on when a
partially-completed MSB should be rejected and when accepted, but some
guidelines are given here along with a statement of what happens to the
data in such cases. Point by point:
- All data acquired at the summit are shipped to CASU and WFAU
whether or not the MSB they came from was rejected.
- You can't cause someone to miss out on data by rejecting an MSB;
the worst that can happen is that the data are taken over again, which
is an efficiency issue only.
- Accept/Reject status is obtained from the OMP database by CASU
and appears in the FITS headers which reach the science archive. So
there is never ambiguity.
- If you are 50% of the way through an MSB and the weather
conditions go off, reject it and it will be repeated in its entirety on
a subsequent night.
- A reasonable cutoff for not
rejecting is 90% completion. In that case please ensure that you put a
note in the night log and use the observer feedback form for the
project in question so that the survey head can reinstate whatever part
of the MSB they wish.
Empty Queue Time
If there are no suitable UKIDSS MSBs given current conditions, then the
UKIDSS observer should firstly exercise flexibility of 0.1 arcseconds
in the entry in the "seeing" field in the QT. The rest of the fall back
sequence is detailed on the Priorities Tonight page. If still nothing,
then you are allowed to do your own backup if
you have any,
but it is essential that in doing so you adhere to the WFCAM template
library sequences, which will ensure that the data will be reducible
when they reach the CASU offices for pipeline processing. A project is
available for this type of observing: U/UKIDSS/B2. If you have none of
your own backup, check U/UKIDSS/B1 (the staff equivalent, which will
occasionally have MSBs for execution).