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30th August 2005  Hoyle committee room 11.30 - 13:05

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

Agenda
------

1.  Actions from last meeting
2.  Comments on WFAU minutes
3.  Data archives update - UKIRT, WFCAM, AAO, ING
4.  Review of UKIDSS meeting
5.  Upcoming VDUC meeting
6.  WFCAM news and JAC telecons
7.  Optical processing update
8.  VDFS update
9.  AstroGrid liaison update
10. AOB monthly reports, hardware

Minutes
-------

1.  Actions from last meeting

MJI  all reports written
JRL
MR

JRL  has sorted out the connectivity issues with AAO which was holding up 
     the development of the AAO archive

WJS  has checked that the Nov 2004 version of the SADT Definition Document
     is the latest version

STH  has yet to trial the test version of the SADT available for both VISTA
     and VST. Will contact Martin Folger to progress this -  ongoing       <<<<

MJI  circulated the quarterly plan

MR   has improved the look of the front page of the WFCAM raw data archive
    
JRL  has not finished sorting out local scripts for easy access to the 
     mirrored OMP data base tables - ongoing                               <<<<

JRL  reported on the summit pipeline timing tests at the JAC telecon

MR   has investigated the properties of the sky calibration frames. NAW and
     RGM raised the issue of placing the presentations given at the SV
     meeting on the web. It was decided that these could be placed within
     the "Presentations" section of the Documentation web page.            <<<<
     There may also be other presentations given (eg Survey Heads meeting)
     that may be suitable for inclusion.
     It was also decided that MR should also write up the investigations
     into the flat fields and sky frames as a document.                    <<<<

MR   has put more explanatory text on the processing progress web page. The
     next addition will be a Known Features page for each semester
     - ongoing                                                             <<<<

STH  has finished the 3 remaining RIXs in the ETC document

PSB  has checked that all the various VISTA documents are up-to-date

WJS  has not yet checked the VISTA template definitions  - ongoing         <<<<

MJI  raised the calibration/science frame issue at the VDMT meeting. Again
     the general feeling was that it would be simpler to classify the 
     observations of the standards as calibration frames. The decision now
     rests with the VISTA Project Office.
	       
PSB  is waiting for contacted from JPE about the status of the SADT with 
     respect to the RIXs - ongoing                                         <<<<

EGS  has made the stacking software available for specific requests

EGS  finished and distributed his SV document and received many comments
     at the SV meeting in Edinburgh (see item 4).

JRL  finished writing the ADASS abstract

ALL  have kept the .away file up-to-date (if not altogether accurate)


2.  Comments on WFAU minutes

There were no comments


3.  Data archives update - UKIRT, WFCAM, AAO, ING

UKIRT: is up-to-date.

WFCAM: the raw archive is up-to-date. The transfer of the raw data to ESO
has 3 nights left to do. MR is currently working on setting up a DQC archive
for WFCAM. This is a long-term project. NAW mentioned SAADA as being
relevant to this.

AAO: JRL has sorted out the access to the mirror. Getting the rest of the
archive functional will take about 2 weeks.

ING: almost all the DVDs have now been read. The transfer of data via
Internet has been progressing successfully for the last 2 months. It has
been noticed that a number of DVDs contained repeated data, so some form of
intelligent clear-out script is required to remove the duplicated data. 
EGS will help RWA with this.                                               <<<<


4.  Review of UKIDSS meeting

The UKIDSS SV1 meeting was held at Edinburgh on 18 August and went very
well. STH went through some of the actions that had been noted.

It was requested that MJI produce a PDF version of the catalogue parameters
document.                                                                  <<<<

GIF versions of the PS plots on the WFCAM Reduction Progress pages have now
been made.

The catalogue generator has been updated to produce more magnitudes
(Petrosian, Kron, Hall). Also error estimates have been added. The
largest aperture used have now been shrunk so that the largest is now
only 24" diameter.  The previous largest, 64" diameter, was bigger than the
default background tracking scale and therefore pointless.

The next SV meeting will be held on Wednesday 21 September in Cambridge. On
the preceding Tuesday (20th) Cambridge will also host a WFCAM calibration
meeting.

MJI noted that next Tuesday (6th September) there will be a VDUC
meeting in Cambridge and that as many as possible should be around in order
to answer questions if any arise. STH said that his photometry document
should be out by the 6th.

EGS mentioned one of the issues raised at the SV meeting. He had done an
investigation into the sensitivity of stacked only versus stacked interleaved 
data and found that the stacked data was more sensitive. One reason for this 
is that the detection algorithm is not currently tuned to work with large 
hedgehog-shaped PSFs.


5.  Upcoming VDUC meeting

In preparation for next week's meeting, MJI and STH are preparing a document
which will describe the plan for UK VISTA data reductions. This will not be
fully detailed, but will describe what documents will be prepared for the UK
review (to be held next year). This document will also contain the new
VDFS deliverables schedule. STH will distribute this document for comment 
by tomorrow.                                                               <<<<

No agenda has been distributed yet, but MJI and NCH will be giving
presentations summarising progress since the last review.


6.  WFCAM news and JAC telecons

Two JAC telecons have been held since the last meeting (27 July and 16
August). The main items discussed were how far the requirements of the
summit pipeline have been met, particularly with respect to its speed.

WFCAM is currently on the telescope and working. An automated guidestar
acquisition system is now in place.

Fine tuning of the optics has been carried out to sort out tilt etc. Images
were found to be 0.65" on all chips (Gemini reported 0.5" images in V on the
same night) on the 1st night of on-sky tests.

The field lens has been cleaned so that the worst of the scattered light/
thermal emission problems (the "crud") has been eliminated.

MJI reported that he measured the intrapixel capacitance (after RGMs comment
regarding this at the last meeting) for WFCAM (and also VISTA).  The charge
coupling due to this effect causes a modest correlation beween stored charge
on any pixel and its immediated neighbours.  The primary consequence of this
is that the noise at the pixel level is correlated and this in turn leads to 
a measured chi^2 that is smaller than it would be for random (photon) noise,
a factor of 1.2 for WFCAM.  In turn this leads to an overestimate of the
gain (e-/ADU) and hence the sensitivity.  This also has implications for the 
parameter errors estimated from PST fitting, but only at the 10% level for 
WFCAM.  It is quite likely that other problems in estimating realistic errors 
will be at least as large.

Reprocessing has been carried out on all data affected by the pipeline 
software stacking bug.  Also all the SV data up to and including 19th April 
(SV1) has been reprocessed with the new catalogue generator in order to 
calculate the new parameters, errors etc..  We were all asked to examine 
this new data for problems prior to releasing it and prior to finishing off 
the rest of the 05A data catalogue (re)generation                          <<<<

A prototype crosstalk removing algorithm has been written by MJI, and is in
the middle of consumer testing.  At this stage it is unclear if it is worth
reprocessing all the 05A data again to incorporate this.  MJI, after 
disussions with NCH, recommended using it in anger on 05B data and then
re-assessing the situation re: 05A data further downstream.  The main 
reasoning here being to limit the long-term number of available reprocessed 
versions of the same data.

Some redesigning of the UKIDSS WFCAM survey MSBs has been done to help improve
the observing efficiency whilst maintaining the science return.  The primary
result from this should be a significant reduction in the nightly raw data
rate.


7.  Optical processing update

EGS said that he was dealing with a data request from Caroline van Breukelen
to process INT WFC data covering one of the WFCAM survey areas.

CFH MegaCam and Subaru optical imaging data is also being processed.


8.  VDFS update

No PSB, so no VDFS update.


9.  AstroGrid liaison update

Nothing to report.


10. AOB monthly reports, hardware

MJI said that two new disc servers (8 TBytes each) have been ordered.
A new rack will also be ordered shortly to locate some of the disk server
kit more appropriately.

NAW raised the issue of whether CASU will be involved with an interface/
archive for AAOmega.  Raw data yes, processed data probably online at the
AAO, but MJI will confirm at the next AAT Board meeting.                   <<<<

RGM asked what the next VST milestones would be. MJI said that the
submission of revised public survey proposals will be due by about the end of
September. The proposals will then be reviewed by the PSP for compliance
with the PSP directions and agreements. The PSP Chair will finally report
these findings to the OPC in November.


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

STH  drive test version of the SADT available for both VISTA and VST 
     (contact Martin Folger)

JRL  finish sorting out scripts for access to the summit comments database 
     and make available

MR   further enhance the processing progress web page

WJS  check that VISTA template definitions are sensible

PSB  wait for response from JPE regarding the status of the SADT with 
     respect to the RIXs

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

MR   produce or update documents covering the presentations given at the 
EGS  SV meeting and place on web pages
MJI
STH

ALL  place other suitable presentations in "Presentations" section of
     documentation web page.

MR   write up the flat fields and sky frames investigations as a document

EGS  write a clear-out script to remove the duplicated data from the ING
     archive in consultation with RWA

MJI  produce a PDF version of the catalogue parameters document

STH  distribute VDUC document

ALL  comment on above VDUC document

ALL  think of and carry out tests on the new catalogue parameters data

MJI  confirm AAO plans for AAOmega data