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5th January 2006 Hoyle committee room 10.00 - 13:00
Present: DWE, MJI, PSB, STH, MR, JRL, RGM
Apologies: NAW, EGS, WJS
Agenda
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1. Actions from last meeting
2. Comments on WFAU minutes
3. UKIDSS SV meeting
4. VDMT meeting
5. VISTA ESO public survey meeting
6. VDFS VISTA update
- telescope status
- VIRCAM Status - AIT
- VDFS docs status
- DRL status
- ETC status/workpackage issues
- Template issues - twilight, njitter protocol
7. WFCAM processing
- photometric calibration status
- recent changes to pipeline
- progress on PSF fitting
- data reduction progress
8. Data archives update
- AAT, ING, WFCAM, UKIRT
9. Optical processing update
- VST, IPHAS,
10. AstroGrid liaison update
11. AOB.
- GAIA
- WFMOS
Minutes
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1. Actions from last meeting
WJS has passed on the SADT comments to Martin Folger
JRL has not finished off the OMP database access scripts - ongoing <<<<
JRL has not added an MSB quality flag to the FITS header - ongoing <<<<
MJI has discussed the flatfield and sky properties draft report with MR
with the conclusion that a paper will be based on it
MJI continues to investigate the merged classification
statistics - ongoing <<<<
WJS was not present so it is unclear whether visiting RAL during AIT3a
is still a possibility - ongoing <<<<
PSB has discussed UKLight with Peredur Williams and there is nothing
significant to report
WJS provided PSB with updated measurements of the VISTA filter
characteristics
EGS distributed a set of options for the group web pages and are collating
DWE the results. An offline meeting was suggested to discuss further
progress. DWE added that the VDFS web pages now have a search facility
MJI has produced a diagram to explain the cross-talk pattern. This has been
added to the SV report (http://www.ast.cam.ac.uk/vdfs/docs/reports/sv)
STH has recommended (in conjunction with the calibration working group)
a new strategy for observing standards. 2MASS can be used to calibrate
JHK to better than 2% (tested against UKIRT FS). Issues for Y and Z
have not been fully resolved yet. Observing of standard fields has been
recommended to be every 2 hours on photometric nights only. Among other
things this will provide useful diagnostic measures and external
verification. The report is available at
http://www.ast.cam.ac.uk/vdfs/docs/reports/2masscal.pdf
STH said that he was considering attending a meeting on photometric,
spectrophotometric and polarimetric standardization in Belgium
(8-11 May 2006 http://www.vub.ac.be/STER/standards/stds.html)
STH did not select a more crowded field in which to carry out further
photometric tests. It was by-passed by the decision to use 2MASS to
investigate and measure the large-scale systematics in the photometry.
DWE tested circular apertures for the PSF work and found no improvement due
the symmetry of the modified Gaussian polynomial functions being used.
DWE generated some colour-colour plots from a crowded field (M17) to test
the PSF-v-pipeline photometry (see item 7)
2. Comments on WFAU minutes
It was noted that the PI data has been released and this is welcomed by CASU.
The "missing" data from 17 April was discussed. The OK_TO_COPY file is dated
7th October along with all the other SV data, so it is unclear what exactly
happened.
RGM raised the issue of data transfer. He had noted with help from PSB
that 2 TB of data had been transfered in a few days around 19
December. Although this was 40 nights of data only 1 night was logged
as having been successfully copied.
RGM had been in comunication with Nigel Hambly (WFAU) and Nigel had
explained that there had been a power-cut at the WFAU end and the copy
had been aborted. The copy status would be updated soon.
[Late breaking news; as of Mon, 9th Dec, the copy status now showed all
data upto 29th Sep had been successfully copied to WFAU.]
RGM stressed that the important thing was that there is no problem with
the transfer rate and that therefore the current 2 month backlog in the
transfer of processed data could be resolved with a few days of sustained
transfer. As of 6th, Jan, all WFCAM data upto Dec 10th Dec (apart from 3
nights) had been processed and checked by CASU as available for WFAU ingest.
RGM noted that this was an impressive achievement to start the New Year with.
STH asked whether the issue of inconsistent images attributes mentioned in
recent emails had been sorted out. MJI noted that this was being
investigated and was due to incorrect information in the raw frame FITS
headers for a 2 week period during May. JRL had manually fixed most of
these at the time of processing the 05A data but a few may have sneaked
through.
3. UKIDSS SV meeting
MJI reported on the UKIDSS SV meeting held in Edinburgh on 15 December. See
http://wiki.astrogrid.org/bin/view/UKIDSS/SciVersEdinDec for the minutes.
The main topics discussed were the release policy and how to make the best
of the processed data (see below).
It was noted that stacked DXS data and catalogues need to be generated by
the end of January. EGS is doing this work. <<<<
The UDS team have requested that some processed 05B data be released by
then too since no 05A UDS data is available. The status of this request is
still unclear.
RGM reported that most of the problems arose from people using the wrong
parameters or not tuning the matching criteria appropriately. For example,
Hall magnitudes were still being used by the GPS and GCS SV teams, even in
very crowded regions, rather than the recommended aperture magnitude.
Furthermore a matching radius of 5" was being used, which naturally gives
rise to many outliers in crowded regions. MJI demonstrated at the meeting
how good the catalog data is if you use the correct procedure.
RGM has been investigating star-galaxy classification by comparing the
pipeline results with respect to Sloan photometry and spectroscopy. The end
result is that they are very comparable when taking into account the
different noise levels.
At the meeting Steve Warren raised the issue of Moon reflections and various
ghost images.
In order to help users assess if they are getting the most out of the data,
MJI said that he would place example colour-colour and colour-magnitude
diagrams for IC4665 and M17, together with a brief howto, in the SV report.<<<<
4. VDMT meeting
MJI noted that one of the topics discussed at the last VDMT meeting (16
December) was the new requirement for a live up to date on-line ETC. This
was discussed later (see item 6).
The next VDMT meeting will be in February.
5. VISTA ESO public surveys meeting
STH and RGM attended this meeting (20 December at QMW) which was to start the
discussion of the ESO public surveys on VISTA.
RGM was concerned to note that the VISTA Z filter had not been ordered yet.
Individual coordinators (below) were designated to coordinate further plans
and discussion on potential VISTA public surveys to prepare for the further
meeting in the first week of February. Please contact them to join the
discussions and flesh out draft proposals.
Overall Jim Emerson j.p.emerson@qmul.ac.uk
to coordinates the plans below and others that are proposed
Hemisphere Survey Andy Lawrence a.lawrence@roe.ac.uk
this includes the VISTA counterpart to the VST ATLAS survey
Galactic Plane Phil Lucas pwl@star.herts.ac.uk
this includes the VISTA counterpart to the VST VPHAS+ survey
IR - 1000 sq deg Will Sutherland wjs@ast.cam.ac.uk
this is the VISTA counterpart to the VST KIDS survey
IR - 5k Sarah Bridle sarah@zuaxp0.star.ucl.ac.uk
this is the VISTA counterpart to the proposed CTIO
Dark Energy Survey
this may give way to the IR-1000 sq deg survey
Magellanic Clouds Maria Rosa Cioni mrc@roe.ac.uk
Deep - 100 sq deg Gavin Dalton g.dalton@physics.oxford.ac.uk
The milestones for the public surveys are as follows:
15 Jan 2006 Announcement
15 Mar 2006 Deadline
Jun 2006 ESO Public Surveys initial selection and meet with PIs
Oct 2006 Final proposals to OPC
Nov 2006 OPC decide on proposals
Apr 2007 VISTA commissioning and acceptance
May 2007 Science Verification
May 2007 ESO Public Surveys start
Jun 2007 Call for Proposals for other surveys
Sep 2007 ESO open time starts
The next meeting will be end of January or beginning of February probably
at RAL.
6. VDFS VISTA update
- telescope status
No WJS, so no update
- VIRCAM Status - AIT
PSB said that AIT3 had happened and that he had obtained about 50 dark frames
(which had some light leaks). These were very useful since they helped clarify
the orientation of the chips which was different to what was originally
thought.
A particular problem is the ordering of the extensions within the FITS files
which is essentially random. The data is read out in blocks of 4 detectors
and each block is stored on a first-come first-served basis and routed like
that to the ESO archive. Not only does this look very unprofessional, it
will cause programming problems in the future. It was felt most strongly
that this situation should be corrected at source.
MJI noted that the ESO WFI MEFs do not have this problem and said that he
would ask Konrad Kuijken what the situation is with the OmegaCam data
acquisition. <<<<
- VDFS docs status
PSB reported that there is a bit of a backlog with signing off these
documents, although they are not waiting on any CASU action as far as we
know. Some modifications have been carried out in order to be compatible
for the DRL release v0.1. During the last 2 weeks of December three
documents have been sent off for approval. The "DFS Impact", "Calibration
Plan" and "DRL Design" are now all awaiting signatures before they
can be released. It was felt important that these documents get to ESO soon.
There was some discussion as to when the next deliverable of the DRL (v1.0)
is. The last GANTT chart we have says 24 March, but it is unclear if this
is the current target date. This needs clarifying. <<<<
- DRL status
JRL reported that he had sent off an unofficial release of V0.1 of the DRL
to ESO which contains 4 recipes extensively tested (to destruction) by PSB.
- ETC status/workpackage issues
A new work package seems to have been created by the VISTA overlords, namely
a live up-to-date fully functioning web-based ETC provided by CASU. The list
of demands is quite large and will take a considerable amount of work to
implement and test. There was some discussion as to what part of the VDFS
project should be deferred in order to free up some manpower effort to
undertake this task.
- Template issues - twilight, njitter protocol
PSB and MJI noted a slight problem with the twilight template design
in that it lacked an offset/jitter pattern to make the twilight flats
useful. MJI, JRL and PSB will put their heads together and suggest a
suitable strategy. <<<<
There was some discussion regarding the level within a flat and real-time
determination.
7. WFCAM processing
- photometric calibration status
STH noted that the Photometric Calibration document has been revised and
now sent off as a recommendation. This covers J, H and K. For Y and Z the
plans are to further assess 2MASS using a linear colour term (as is currently
being used) by comparing the Z-band calibration with SDSS. The crucial
proviso is to use a colour limit (eg. J-K < 1) so that the population
density differences between dwarfs and giants and extremely reddened stars
are not a problem.
- recent changes to pipeline
JRL reported that the pipeline is stable at the moment. Since the last meeting
the biggest change is an upgrade to the determination of the skies. All
available suitable frames will used to determine a "local" sky frame to
effectively completely eliminate extra contributions from rms noise.
A few minor alterations/bug fixes for the summit pipeline requested by JAC
have also been implemented.
- progress on PSF fitting
DWE reported on PSF fitting, the main progress having been on robustifying the
measurement of the PSFs. A report on the latest results has been written and
will be released soon. <<<<
Data covering M17 was analysed and colour-colour plots generated in order to
compare the performance of the PSF and standard pipeline photometry. For the
frames with the best seeing, there was not much difference between the two
methods. However, for worse seeing it was noticed that the pipeline performed
better. The reason for this was that the PSF was changing between the
microsteps and thus a standard PSF model was not appropriate. The astrometric
accuracy was not affected by this and similar performances was obtained for
both methods.
In order to cope with this situation a new PSF determination method is being
developed in which the microstep interleave components are analysed in
parallel. Work on this is still in progress and has delayed incorporating
PSF measures into the catalogues - though in lieu of the earlier comment
this is hardly science-mission critical.
- data reduction progress
Tapes of WFCAM data for the period up to the 12th of December were received
on the 21st December. These were ingested over the holiday period and
processing of earlier data continued over the supposed Christmas break.
CASU are currently processing data up to mid-December and have completed
processing all data up to the end of November ie. as planned, on
average about a month behind data being taken at the telescope. For an
up-to-date view of the processing status see http://apm15.ast.cam.ac.uk/wfcam/
report_night_reduction_status?semester=05B&SUBMIT=Submit+Query, also
accessible via the vdfs front page.
The state of processing on 6th Jan, 2005 was:
data up to Dec 17th was either processed and checked or is being processed
data up to 22nd Dec has been verified and ingested
8. Data archives update
- AAT
MJI asked about progress with the AAT archive. JRL noted there were still
one or two minor changes to make. JRL also said that he would ask the AAT
if there is any more data that is available for ingesting. <<<<
- ING
RWA is progressing well with the CD-to-disk dumping. There are about 2000
CDs left to process which should be completed by the end of January. MJI
noted that the internet transfers were continuing to operate smoothly.
- WFCAM
MR said that the transfer of raw data to ESO is progressing, albeit slowly.
Data up to 9 October has been transfered. The transfer speed remains
unchanged even after ESO-end upgrades. The Cambridge Raw Data Archive has
data ingested up to 12 December. He noted that a tape containing data for
the period 13-22 December arrived on Wednesday 4th.
- UKIRT
There is no new data for the UKIRT archive at the moment. Probably
unsurprising given the time WFCAM has been on. JRL said that he would ask
if there is any more data that needs transferring and ingesting. <<<<
9. Optical processing update
- VST
MJI said that the VST UK-led public survey proposals ATLAS and VPHAS++ had
been successful, but that we are unlikely to get any data to process this
academic year.
- IPHAS
In lieu of VST data, data processing is carrying on for the IPHAS consortium
for semester 05A/B (~80 nights of INT time). This should start to ramp down
over the next year.
10. AstroGrid liaison update
STH said that he had been unable to attend the AstroGrid deployment meeting
at Leicester due a clash with the SV meeting in Edinburgh.
11. AOB.
- GAIA
MJI reminded us that the PPRP visit to Cambridge will be on the 9th February.
This is an important part of our Gaia grant bid and potentially forms a
significant part of CASU funding from 2007 onwards. A PSF and pipeline demo
(or similar) will be required for this to emphasise the synergy between the
different projects that CASU have been involved in. RGM suggested that some
dry runs for this would be a good idea preferably before the end of January.
- WFMOS
MJI reported that he is involved in one of the two WFMOS concept design
studies as part of the Aspen programme for Gemini 2nd generation instruments.
He noted that there might be some future CASU involvement in this project
(for background info see http://www.gemini.edu/files/docman/science/aspen/
WFMOS_feasibility_report_public.pdf
It was also reported that STH has finished his term on the DAC, but that MJI
has been co-opted onto the Staff Committee.
PSB reported that there had been a site-wide power cut on New Year's Eve.
One disc was lost on a CASU RAID array, but no data was lost. All machines
are now up and running after a bit of hiatus. There were problems trying
to reboot the machines of MR and EGS. It was requested that they sort them
out so that they can be rebooted easily (and preferably automatically if
they happen to be away) since they now serve a lot of the web-based
information pages. <<<<
JRL said that the ADASS 2007 venue had been sorted out and that the
conference dinner (fish?) would be held at the National Maritime Museum.
Continuing Actions
------------------
JRL finish off the OMP database access scripts
JRL provide a script to add JAC MSB quality flag to the FITS headers
MJI finish investigating merged classification statistics
WJS advance the proposed CASU visit to RAL, in particular check that
having it during AIT3a is OK
New Actions
-----------
EGS hold meeting to discuss the future design of VDFS web pages
DWE
MJI
EGS generate stacked DXS data and catalogues by the end of January in
liaison with Alastair Edge
MJI produce colour-colour and/or colour-magnitude diagrams of IC4665 and M17
along with a brief howto
MJI ask Konrad Kuijken about the ordering of OmegaCam extensions within a
FITS MEF file
MJI clarify deliverable date for DRL V1.0
PSB suggest a suitable strategy for jittering VISTA twilight flats
JRL
MJI
DWE release latest PSF report
JRL finish mods to AAT archive and inquire if there is any more AAT data
that needs ingesting
JRL ask if there is any more UKIRT data that needs ingesting
EGS sort out an automatic and reliable reboot for apm14 and apm15
MR
