3rd January 2008 MJI's office 11:30-12:35 Present: STH, PSB, MJI, DWE, JRL Apologies: NAW, EGS, MR, RGM Agenda ------ 1. Actions from last meeting 2. Comments on WFAU minutes 3. Recent meetings/visits 4. Data archives update 5. Optical processing update 6. WFCAM news 7. VISTA news 8. ADASS 2007 9. AOB Minutes ------- 1. Actions from last meeting MR has not advertized the illumination correction information - ongoing <<<< STH has not checked the advertized illumination correction information and update the relevant section in the calibration paper - ongoing <<<< MR has not yet performed the backup verification tests using 4 old LTO tapes - ongoing <<<< ALL still providing comments on photometric calibration paper - ongoing <<<< DWE switched off the database server on apm1 and will remove the related files at the next Windows update. MJI has reviewed the user accounts on the APM cluster. ALL have sent in reports for November and December to STH by 3rd January. JRL has contacted AAT and data transfer has now resumed. JRL still checking why pipeline catalogue software and toolkit give different results in a few specific cases - ongoing <<<< JRL has written a first draft letter of support to Omar Almaini and Phil Lucas regarding future of UKIRT/UKIDSS. This needs a few more tweaks and will be circulated within the group - ongoing <<<< STH has not fed back comments on Plone/HTML websites - ongoing <<<< 2. Comments on WFAU minutes NCH has requested a CASU account on djedefre to pick up the WFCAM newtork transfer efficiency issue again. (As it happens, UKLight is down this morning due to a broken fibre in Middlesbrough.) 3. Recent meetings/visits Several from CASU attended the recent UKIDSS workshop in Garching. Items arising from this are in the WFCAM and VISTA sections. 4. Data archives update AAT: JRL noted that the AAT archive transfers were started again and are now up to date bar a bit of squishing. ING: transfers continue seemlessly as usual. Data to the end of December 2007 are currently being checked. WFCAM: the remaining week or so of 07B data has not yet been shipped. UKIRT: no change MJI asked JRL if he could fill in the EVO census of data holdings and archives questionnaire (deadline 20th January). <<<< 5. Optical processing update No change 6. WFCAM news MJI noted that the current plan is to transfer all WFCAM 08A data via the Internet. The desirability of assorted tests during January was raised again - the remaining WFCAM data for 07B would be a good starting point. The standard processing of WFCAM 07B data up to and including 24th November is complete. The reprocessing to reduce the parquet floor effect is about a week behind; whilst the remaining week or so of 07B data is not yet available for processing. Checking and detector zero-point (re)calibration is complete up to the 16th November and all 07B processed data prior to this point has now been flagged as ready to copy. There followed a short debrief on the UKIDSS meeting focussing on feedback from users at the meeting and their wish list for improvements. A few regions show either poor background subtraction or artefacts in the background - a good example being the Orion complex particularly the M42 nebula. At the UKIDSS meeting Phil Lucas encouraged NCH to dig out an example of this from the GCS. MJI had looked at this after the UKIDSS meeting and found that most of the problem (apart from the known ancient cross-talk bug issue) was caused by the decurtaining stage introducing a "Maltese Cross" pattern in the background. This is a known feature of the decurtaining algorithm that occurs in rare cases where the strongly varying background interferes with the curtain fixing estimator. MJI tried out a simple fix that seems to do the trick and asked JRL to implement a test version of this in the pipeline for assessment on other tricky fields. <<<< The current sky estimation strategy generally works well but there are a few specific cases where problems occur. After discussions with AJA both prior to and during the meeting a simple method of alerting the pipeline to such cases was agreed on and will be implemented for future observation MSBs when required. This will hopefully get around the majority of the cases where the pipeline is trying to second guess the best strategy without full prior knowledge. The desirability of elliptical apertures for galaxy photometry was raised - interesting since that was what we originally were going to do before a majority voted for circular aperture photometry. The obvious compromise would be to stick with the current fixed circular apertures and solely use elliptical apertures for Petrosian, Kron and Hall measures. We await the outcome of the prioritised UKIDSS wishlist (and upcoming grant review) with interest. The GPS folk want better photometry in nebulous regions, both from a "point source" detection and flux estimation point-of-view. At the meeting we noted that using a smaller scale background tracker was the simplest thing to try out, but whether this will really deal with the problem is still a moot point requiring further testing. Assorted deblending issues were raised ranging from too little (occasionally obvious pairs of sources are not deblended - see earlier action) to too much (large galaxies getting split and subsequent Petrosian photometry not being reliable). One can only conclude that on average deblending must be about right. Desirability of full iterative PSF model fitting and Sersic profile fitting (presumably in both cases only for objects/fields worth bothering with since this will be seriously CPU intensive). This has always been in the long term development plans but has not been completed yet. Finally, STH noted that some users were uncertain how to make best use of the processed flat file access and in particular were still uncertain about certain aspects relating to astrometry and photometry. After a brief discussion it was felt that although all the relevant information was available on the CASU plone site and via emailing casuhelp if required, a few specific links in the catalogue information page pointing to the relevant technical pages would be worthwhile. STH was tasked to make it so. <<<< 7. VISTA news VISTA: The last we heard is M1 will be accepted in factory at end of February. We received an alpha release of CPL 4.1 which allows use of compressed FITS files; however PSB is having problems building it. MJI, JRL, PSB as well as JPE attended UKIDSS workshop in ESO in Dec; as well as WFCAM results, this was an excellent opportunity to discuss various VISTA issues with ESO staff. It seems the Paranal pipeline computer is delivered but not installed and will be set to not analyse science data. There are some worrying unsettled issues regarding the timely delivery of VIRCAM data to the UK. On the ongoing request for N118 filter data, JPE reports that he doesn't have machine-readable version. JRL (in particular) has further analysed linearity data from the July engineering run - a report is in final draft. MJI suggested that finishing this off should have high priority. <<<< 8. ADASS 2007 All were asked to review the printed copy of the ADASS 2007 proceedings for obvious errors. This needs to be done by the end of the month. <<<< 9. AOB MJI noted that the upcoming grant review and asked for contributions for the main themes to be presented. <<<< MJI pointed out the much improved, including mains power supply and general tidied up and rearranged, store/computer room. Related to this PSB noted that we were still awaiting a quote for the partition for the main room. MJI asked STH to help review our potential involvement in the PLATO mission assessment study for the ESA Cosmic Visions (2015-2025) programme. <<<< Continuing Actions ------------------ MR advertize illumination correction information STH check the advertized illumination correction information and update relevant section in calibration paper MR perform backup verification test using 4 old LTO tapes ALL provide comments on photometric calibration paper JRL check why pipeline catalogue software and toolkit give different results in a few specific cases JRL draft letter of support to Omar Almaini and Phil Lucas regarding future of UKIRT/UKIDSS and circulate within group STH feedback comments on Plone/HTML websites New Actions ----------- JRL reply to EVO questionnaire by 20 January JRL implement decurtaining modification in test mode STH place more links on Catalogue Generation and Photometric Calibration Plone pages JRL finalise and issue VIRCAM linearity report ALL review printed copy of ADASS 2007 proceedings by end of January ALL be ready to contribute to presentations for grant review STH review possible involvement in the PLATO assessment study MJI