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18th July 2006  Observatory meeting room 11.30 - 13:30

Present:    DWE, MJI, JRL, PSB, MR, STH, WJS
Apologies:  RGM, EGS

Agenda
------

1.  Actions from last meeting
2.  Comments on WFAU minutes
3.  Data archives update     - AAT, ING, WFCAM, UKIRT
4.  Optical processing update
5.  WFCAM news               - reprocessing 05B
                             - progress with 06A
                             - non-linearity update
                             - MSB ID checksum for tagging bad MSBs
6.  VISTA news               - VIRCAM AIT status and data
                             - VDFS docs status
                             - DRL status
7.  AOB                      - hardware update
                             - upcoming VDMT meeting
                             - UKLight saga

Minutes
-------

1.  Actions from last meeting

MJI  has made no further progress investigating the merging of 
     classification statistics. Most of the relevant information has been
     passed on, so it was decided to drop this as an action.

JRL  has started implementing the fix to the problem with the UKIRT archive
     (missing header information problem) - ongoing                        <<<<

EGS  has not updated the INT WFC web pages with the latest flat-field 
     and fringe frames - ongoing                                           <<<<

STH  has acquired the data from the 2MASS Touchstone fields. These go 
     roughly 1 magnitude deeper than the 2MASS sky survey and have been
     observed a large number of times. There are 7 fields that overlap 
     WFCAM standard fields. It was thought that it would be a good idea to 
     add these fields to the VISTA Calibration Plan (if the data
     could be made public). STH was asked to update the Calibration Plan
     document in general given the benefit of the WFCAM experience         <<<<

DWE  are still finalising the content of the Plone site. DWE said that many
EGS  of the technical pages had been written - ongoing                     <<<<
STH  JRL asked DWE to help with setting up a local ADASS Plone site
MR   (this was an action a few weeks back - but got lost)                  <<<<

MJI  arranged with RWA to fill in the 2004 gap for the INT in the 
EGS  ING archive. This is now underway.

JRL  emailed MJI on the whereabouts of dome linearity sequences

MR   emailed Paul Hirst concerning various minor problems with 06A data.
     
EGS  have started investigating the UDS complaints regarding the pipeline 
MR   stacking and cataloging components. MR reported that he had received 
     the data this morning (including the list of frames that made up the 
     stack).


2.  Comments on WFAU minutes

JRL was puzzled by the comments regarding problems with the catalogue 
generating software since he said he had not received any emails saying
that it wasn't working. He said that he would email WFAU to check out 
what the problem is.                                                       <<<<

MJI noted that there might be some subtle consequences caused by the 
recent changes to the software. MJI, MR and JRL are checking.              <<<<


3.  Data archives update 

AAT - no further news

ING - no further news

WFCAM - MR reported that tapes up to 5th July had been read onto disc and
ingested into the raw data archive. ESO have transfered up to 10 June. The
new data does not have any missing chips, but there are still a few files
with zeros in one of the chips. These tend to be at the start of the night.

MJI said that a large proportion of the data from the first 06A month was
engineering data and wondered if there was a way to stop this data
being transfered to Cambridge.  MJI will email JAC about this.             <<<<

UKIRT - no further news


4.  Optical processing update

No changes since last meeting.


5.  WFCAM news

Reprocessing 05B: MJI said that about 6 nights have been reprocessed using
the latest sky subtraction algorithm. These mainly concerned UDS processing.
Most of these were transferred directly to the UDS group for inclusion in
DR1.

Progress with 06A: Processing is on track.  However, none of the data has 
yet been flagged as "OK_TO_COPY" due to the blockage caused by DR1 and also
because of some further changes to the Y and Z calibration which need a bit 
more work to incorporate the effects of Galactic extinction.  STH said
that a Z comparison with respect to Sloan z' is being carried out.  For
JHK extensive tests on the current calibration and colour equations suggest 
they are well within spec and should probably be left well alone.

Non-linearity update: STH reported that the recently taken dome flats have
revealed that WFCAM is linear to better than 1% over almost the full range 
up to saturation.  A noticeable variation in the background illumination 
occurred while the recent series of dome flats were taken.  This was 
monitored by taking short exposures between each test exposure.  After
correcting for this drift there was no deviation from linearity above 1% 
until 40,000 counts, which is where saturation begins to take effect. This 
agrees with analysis of previous dome flat sequences.  Further on-sky tests 
using different exposure times for standard star fields also support the
inference that WFCAM is essentially linear up to saturation. It was 
noted that this still does not account for the slight non-linearity apparent
in the 2MASS comparison.  STH noted that Roc Cutri had reported to him that
the linearity of 2MASS has only been tested to the 2% level and this may
be the root of the discrepancy.

MSB ID checksum for tagging bad MSBs: JRL said that the JAC ID checksum
method doesn't uniquely identify an observed MSB and is the reason why the
information from the OMP database relating to bad MSBs has not been used.
JRL and MJI will look into this further with JAC's help and see if there is
a viable alternative.                                                      <<<<

It was noted that there were a few pipeline problems that needed fixing
and MJI pointed out that these should take priority over assessing VISTA 
AIT data.                                                                  <<<<


6.  VISTA news

VIRCAM AIT status and data: WJS said that the telescope was now in the dome
and that the large external crane had now gone away.  There will be an
acceptance test at the end of August.  He then gave an update on other 
aspects of the system.

The camera was cold tested with an illuminated spot throughout June with PSB
visiting RAL for one day to help take a series of test data.

The camera has now been moved to the other end of the building at RAL close 
to the transport container. Some handling trials will be carried out next. 
It was unclear whether the camera will be going back into the clean room 
before it gets shipped. PSB said that another day visit to RAL to gather 
data would be useful if it was feasible.  There is also the possibility of 
carrying out tests at the Paranal laboratory.

The current schedule has the camera being shipped in late September.

JRL said that he had started writing a report on the darks obtained from the
AIT tests. The data has showed that the curtaining level is low (+/- 10
counts) and its removal looks promising.  Hot pixels do subtract out, 
providing the appropriate darks taken under the same exposure conditions
are used, except for chip 16 which needs further investigation. There is no 
crosstalk but there is persistence (more data needed).

PSB said that he has had a request from Sandra Castro to provide some CPU
and I/O benchmarks and that these were needed by the end of the month.

VDFS docs status: PSB said that there was no change. MJI said that he would
raise the issue of releasing the FDR docs++ again at the VDMT meeting.     <<<<

WJS mentioned that there is a change request in for the camera to support 
a modified readout mode. This involves a destructive read/reset on a per
row basis to improve overheads.  If this works reliably it should be the
default mode for DCS operations.

It was pointed out that overhead time modifications to the Cambridge-based
ETC to take account of parallelisation of some operations await the 
provision, by JPE, of the relevant overhead algorithm(s). PSB said that he 
will make a start on digitizing the graphs needed for the ESO ETC deliverables
and for making available as table help files (see minutes passim ad nauseam).

DRL status: No further news.


7.  AOB 

Hardware update: MJI said that since we now have air conditioning in the
storeroom, two of the noisier disk server machines have been relocated 
there. The next stage is to include apm12 (which has the honour of now
begin the noiseiest machine) in the Debian system so that it can a. be 
included in the processing servers and b. acquire an operating system that
controls its fans properly.  JRL will arrange with JMI to Debianize it.    <<<<
 
STH asked about the location of data. MR pointed out that the DQC database
provides the location of all the processed data.

Upcoming VDMT meeting: There is a VDMT meeting in Edinburgh on 24th July.
STH pointed out that some people had been very naughty and not handed in
their reports and that he wanted them in by tomorrow. This received the    <<<<
usual response.

Additionally, STH wanted short reports on the AIT and the DRL from PSB and
JRL respectively.                                                          <<<<

MJI said that the UK VDFS Review will be held on 2 days in the week 23-27th
October. We are to keep these dates free. The panel will be chaired by Luc
Simard and consist of Gavin Dalton, Tim Naylor, Matt Jarvis and Bob
Nichol. 

It was pointed out that the Plone site will need to be up and running by 
then and there is a need to review the status of all the documentation.
We also need to clarify what documents are needed for this review.

UKLight saga: PSB asked whether we should go ahead with buying the hardware
needed at our end.  Since this amounted to a can of beans or two and would
slash our recurrent network transfer charges PSB was cleared to go ahead with
this.                                                                      <<<<

STH drew our attention to an email from SJW regarding "deprecations". He
said that he would pass this on.                                           <<<<

STH said that there would be an UKIDSS meeting on 25th July in Edinburgh at
which he and MJI would be giving presentations.

STH also drew our attention to various UKIDSS papers that were in the 
process of being published/refereed.

MR announced that he was getting married to Francesca on the 26th August.
Many congratulations from CASU!


Continuing Actions
------------------

JRL  finish the fix to problem with UKIRT archive (missing header information)

EGS  update INT WFC web pages with latest flat-field and fringe frames

DWE  finalize content of Plone site by end of September
EGS
STH
MR

DWE  help JRL in setting up an ADASS 2007 web site
EGS

New Actions
-----------

STH  update the Calibration Plan document (VIS-SPE-IOA-20000-0002)

JRL  contact WFAU to clarify what is not working with the catalogue
     generating software.

MJI  compare old and new versions of catalogue software
MR
JRL

MJI  email JAC to see if it would be possible to exclude engineering data 
     from the data sent to Cambridge

JRL  investigate MSB ID checksum for tagging bad MSBs
MJI

JRL  fix pipeline problems

MJI  raise issue of VDFS documents status at VDMT meeting

JRL  arrange Debianizing apm12 with JMI

ALL  send in quarterly reports to STH (if not already done)

PSB  send in AIT and DRL report to STH
JRL  

PSB  set in motion acquiring UKLight hardware

STH  circulate SJW email regarding "deprecations"