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3rd September 2008 APM comfy chairs 11:30-12:55
Present: RWA, MJI, JRL, PSB, MR, DWE, EGS, STH, RGM
Apologies: NAW
Agenda
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1. Actions from last meeting
2. Comments on WFAU minutes
3. Recent/upcoming meetings - ESO SADT+P2PP, VOTC, ADASS
4. Data archives update - AAT, ING, WFCAM, UKIRT
5. Optical/NIR processing - VST news
6. WFCAM update - general news, reprocessing, bad pixel
masks, pipeline updates 08B
7. VISTA update - general news, report on vircam data,
status of calib frames and science data,
SV programme, hardware, software
8. AOB
Minutes
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1. Actions from last meeting
STH has not finished checking that the Plone astrometry technical pages
are correct - ongoing <<<<
(see minutes from 080332 for further details)
STH although included in the photometry paper the graphic showing the size
of the photometric radial distortion correction has not been included
in the Plone technical pages. STH will also check that the photometry
pages are up to date given the recent changes to the photometric
calibration paper - ongoing <<<<
MJI has ordered some suitable tables for the meeting area, but delivery will
take 4 weeks ! - the trees are still growing
JRL has not produced a web page of HawkI publicity for CASU - ongoing <<<<
MR has not installed JRL's script to flag summit-rejected MSBs during
raw WFCAM data ingestion - ongoing <<<<
It was noted this needed completing before 15 September. JRL also
commented that he was having problems communicating with the Sybase
OMP DB server, another topic for a putative telecon.
ALL considered submission of abstracts for ADASS 2008. MJI and NAW have
submitted abstracts and have been allocated talk slots.
RWA has removed the JKT CD ROMs from the computer room and rationalized
the storage to free up a cabinet (moved to IoA Annexe) and ease rack
access. Multi-backups of this data exist.
EGS implemented a backup scheme for internet-transferred INT/WHT data and
used one of the recently installed LTO4 tape library units to do it
(~3Tbytes = 3 and 1/2 tapes at ~30 Mbytes/s over the network)
PSB ordered the LTO4 tapes needed for the above action
RWA moved the 08A WFCAM raw data backup tapes to the Observatory building
store cupboard
MJI interacted with JAC about the need for a telecon, but has not yet
converged. If it is going to happen it would be best before WFCAM
goes back on - ongoing <<<<
JRL has not yet made minor changes to object masking sky estimation strategy
(see later)
MJI have come up with a plan for a staged software release. This will be
EGS from the Plone web pages and will be located at
http://casu.ast.cam.ac.uk/surveys-projects/software-release
At the moment this is in draft form so not accessible to the outside
world yet. RGM suggested adding the list-driven photometry package,
which is a good idea so will also be included in the stage-I release.
EGS and MJI will continue working on this <<<<
2. Comments on WFAU minutes
None of any great significance, though EGS noted that DR2 became World
public on 1st September. MJI reminded that DR4 still awaits GPS and UDS
before it is completed, which them reminded him, on writing.editing the
minutes, to ask: does the countdown for World release of DR4 start from a
few months back, or from inclusion of GPS and UDS, or some hydbrid release ?
3. Recent and upcoming meetings
EGS will give the CASU presentation for the SADT+P2PP meeting at ESO.
This needs to include VST as well as VISTA. MJI's recent Leiden/Hatfield
presentations can be used as a starting point. We need to think about
presenting timescales for processing SV, initial surveys and steady-state.
This raises the usual issues about stressing at the meeting the need for FTP
transfer of VISTA (and VST) data from Garching. If AAO, ING and JAC can do
it, why can't ESO ? There is also a related major concern over how the SV
data will be transferred to Cambridge in a timely manner for processing.
Given the SV programme for VISTA involves only regions full of large
extended objects, this also brings to a head the need for a sentient offset
sky strategy for VISTA. Examples from WFCAM and VISTA should be used to
ram home this point. <<<<
PSB said that he would help STH prepare for his VISTA Paranal trip by
demonstrating the simulator so that he would have some idea of how to
observe with VISTA. <<<<
JRL and PSB reiterated the need to always take suitable calibration frames
(darks, flats) for all on-sky observations. Acquiring more calibration
data (linearity sequences, gain measurements) will be a high priority as
will nailing photometric throughput/calibration, sky brightness, and
astrometry in all passbands available.
MJI reminded JRL and MR that they have been volunteered to attend the VOTC
meeting in Cambridge on 25-26 September. <<<<
4. Data archives update - AAT, ING, WFCAM, UKIRT
RWA described recent progress with clearing out the IoA of old photographic
plates, survey copies and so on. He noted that the old RGO sky survey
plate copies were now happily installed in their new home in Germany
and even made use of the specially designed, by Ralph Martin, wooden racks,
all gleaming with a fresh coat of varnish.
As for the rest of the archives, all is well and up to date, the
online-verified and corrected (mainly cleaning out non-ASCII characters from
FITS headers !!) copies of the internet-transferred ING archive are freshly
backed up (see earlier item) and JRL is still polishing the UKIRT archive.
5. Optical/NIR processing
Not a lot going on here other than more news on VST commissioning and
shipping OmegaCam to Paranal. VISTA still has a ~6 month lead.
6. WFCAM update
STH said that the photometric calibration paper had been submitted. Many
people fell off their chairs at this news and had to be revived. STH was
asked to make the paper available on the Plone and VDFS sites. <<<<
In light of this startling news, MJI said that he would try and finish off
the technical paper and locate some more smelling salts and wee drams. <<<<
Superceding an earlier ongoing action, MJI suggested using the night of
20080521 as a test for any revised object masking sky strategy since it is
a.) relatively short ~1100 frames and
b.) packed with fun extended objects and different observing strategies and
c.) is the subject of a user feedback query
JRL will look into this. <<<<
RGM had raised an issue via email of a half-moon shaped region on #2 near
the edge, that generates a lot of spurious high-Z candidates. MJI noted
that the bluer passband confidence maps correctly flag this region as
suspect but the redder bands particularly K are not as thorough and many
pixels here get flagged as ok. He will look some more at the bad pixel
flagging method used for WFCAM and see if any painless improvement is
possible. <<<<
Related to this, RGM asked for clarification about the contents of
parameter #55 - the error bit column. The catalogue generator fills this
with a count of the no. of bad pixels, including fractional edge ones, lying
within the default aperture, hence its storeage as a real number. This then
gets incorporated into the WFAU error bit setting as one of several flags.
The catalogue description has been updated to make this clearer.
There was then a brief discussion of the various deals JAC are negotiating,
or have already negotiated, about access to UKIDSS surveys and about the
possibility of a Northern hemisphere all-sky NIR survey to match the proposed
VISTA Southern hemisphere survey.
Finally, MJI noted that for the 09A semester WFCAM will be on the entire 6
month period from beginning of February to end of July, neatly coinciding
with SV and science surveys starting on VISTA. Good job then that STFC are
rushing out details of results of the grant application submitted 15
months ago.
7. VISTA update
PSB commented that it was typical of Paranal bureaucracy that evening meals
at Paranal cannot be a bit more flexible to allow evening twilight flats to
be taken without emaciating observers. The solution is naturally dawn
twilight flats, unless of course these coincide with desayuno.
The lads hammered home that for serious analysis of VIRCAM data we are still
hampered by a lack of calibration data, mainly: good linearity sets;
twilight flats in all bands; multiple darks matching sky and calibration
frames; and offset skies for regions including large extended objects.
Information on the proposed VISTA SV programme can be found at
http://www.ast.cam.ac.uk/vdfs/internal/vista/sv/. As noted earlier,
these will test the offset sky strategy to destruction, and also the
ability to survey at arbitrary PAs.
PSB has produced a beautiful mosaic of the Eta Carina region from a tile
made up of 6 J-band dithered and stacked pawprints, available in
http://www.ast.cam.ac.uk/vdfs/internal/vista/commissioning/ together with
a report of what we have found so far from the data taken.
JRL summarised the contents of this report for those members of the group
with modern attention spans and also noted that there have been a few
software improvements related to linearity, a few bug fixes (naahhhh!!!) ,
and much gnashing.
The Eta Carina data was taken at airmass 2.13 and in July prior to AO tuning,
so achieving (just) sub-arcsecond seeing on all detectors was excellent.
A recent report sent by Gavin on image quality after further tuning shows
that even the design spec can be achieved.
MJI asked about power consumption and fan speed regulation of the VISTA
Blade system according to CPU load, as happens in the WFCAM processing
cluster. PSB will check to see if the new machines' power consumption and
fan speed are regulateable. <<<<
For those of a curious bent, temperature monitoring information (and many
other things can be found at http://ioadpc.ast.cam.ac.uk/mrtg/ for Gaia
kit and at http://www.ast.cam.ac.uk/mrtg-apm/ for apm29 and assorted
other CASU kit.
8. AOB
Not a lot, still no definite news of CASU grant bid outcome and no point
ordering TV monitor until tables have arrived.
Continuing actions
------------------
STH check that Plone astrometry technical pages are correct
STH include graphic showing the size of the photometric radial distortion
correction in the Plone technical pages and check rest of photometry
pages are up to date
JRL produce web page of HawkI publicity for CASU
MR install JRL's script to flag summit-rejected MSBs during raw WFCAM
data ingestion before WFCAM goes back on
MJI discuss topics and suitable time/date for telecon with JAC if needed
New actions
-----------
MJI finish off stage-I software release pages
EGS
EGS write presentation for SADT+P2PP meeting with help from the rest
PSB help STH prepare for VISTA Paranal trip
JRL attend Cambridge VOTC meeting on 25-26 September
MR
STH make photometric calibration paper available on Plone and VDFS sites
MJI finish off technical paper
JRL look into object masking sky strategy using 20080521 as test night
MJI investigate WFCAM bad pixel map issue further
PSB check if new machines' power consumption and fan speed are regulateable
