24 September 2003 Present: MJI, JRL, PSB, DWE, JMI, STH Agenda ------ 1. Actions from last meeting 2. Comments on WFAU minutes 3. Report from RAL camera design review meeting held 17-19th Sept 4. JRL's visit to JAC 5. Progress on deliverables for Quarterly report 6. AOB - filling in .away document nos. and their wrangling There are two reports filed for comments plus Pete's updated ESO docs, discussed under item 5. http://www.ast.cam.ac.uk/~wfcam/docs/reports/interleaving/ http://www.ast.cam.ac.uk/~wfcam/docs/reports/astrom/ http://www.ast.cam.ac.uk/~wfcam/internal/WP2/ Minutes ------- 1. Actions from last meeting STH no progress with Sandy Legget's data, ongoing <<<< JMI have updated and converted the pipeline milestones tasks and dates MJI document to HTML (http://www.ast.cam.ac.uk/~wfcam/docs/milestones.html) JRL and filled in most of the relevant entries. MJI is awaiting AA's return from holiday (re. UKIDSS Survey Manager). It was decided to transfer this to JRL who is about to visit JAC. <<<< MJI it was decided to postpone updating Section 2. of DFS user requirements document since it was not needed by the Camera Design Review. STH still needs to write a context intro for simulation report <<<< STH JRL will discuss the setting up of the photometric standards fields within the characterization plan with Paul Hirst or Andy Adamson during his visit to JAC. <<<< DWE has emailed STH with his additions to the characterization plan. STH will pass these on to JRL who will raise them during his JAC visit. <<<< STH has not yet extended the number of fields that he has established for WFCAM to the south for use by VISTA. It was decided that this should be an early Q4 task with a timescale of 1 month. <<<< DWE altered the documentation web page so that there are release and revised dates next to each entry. The web page was still viewed as having too much information on it and being hard to navigate. The filenames were regarded as unnecessary. The document numbers also need to be added. DWE and STH will sort this out. <<<< DWE did equivalent 2x2 interleaving plots cf. 3x3 demonstration and placed the results on web (part of interleaving report in http://www.ast.cam.ac.uk/~wfcam/docs/reports/interleaving/) DWE had a look at the 2MASS web pages for examples of "interleaving" efficacy, but no suitable information was found. DWE has written report on interleaving work (see above). MJI provided feedback on VISTA IR detector test procedure document to JRL Jim Emerson and Malcolm Stewart, and at the Camera Design Review PSB meeting to the author. PSB sorted out the accommodation, agenda and exact location for CDR meeting at RAL. DWE emailed Andy Batey to request a link to CASU from the research page of the IoA web site. This alteration has not been done yet - monitoring <<<< STH updated the prototype pipeline progress (WFS) scripts and web pages. JMI PSB has obtained the overview of the VISTA IR camera design. However, this was in paper rather than electronic form. MJI will ask at the quarterly meeting about electronic access to these documents. [However, Steven Beard in a pre-emptive strike provided the relevant information - see ~wfcam/public_html/internal/vista/ESO_starter.txt] PSB have ordered a rack-mountable data server PC to go with the recently MJI received LT02 tape drive/library unit. The LT02 is currently being tested on cass38 and is being used to backup the CASU data disks. The data ingest server PC will be a 3GHZ twin Xeon processor system with 4x300 Gbyte IDE discs served through a 3-Ware controller. The operating system will start off as RedHat Linux. Delivery is expected next week, delay was caused by 2 week wait for enclosure. 2. Comments on WFAU minutes It was unclear whether the disc problems encountered at ROE had any parallels with CASU systems. MJI said that he would contact NCH to get some more details. <<<< The proposal for a central VDFS web site was noted. There was some interest in the deliberations going on regarding what distribution of Linux was best. There is a growing feeling that RedHat has too many updates and releases to ergonomically maintain. 3. Report from RAL camera design review meeting held 17-19th Sept PSB reported that the 3 day meeting, attended by 20-25 delegates, was very interesting. While many of the presentations were very detailed, some were still preliminary. In general though the CASU group were impressed. PSB attended all 3 days, JRL and MJI for most of the final 2 days. The latter two gave a presentation of the general plans for pipeline processing VISTA (and WFCAM) data. The camera control software presentation was given by Steven Beard. It was unclear whether he was the only person working on the coding aspect of the VISTA camera software interface. Some concern was expressed if this was the case, due to the size of the task and the tight timelines. An example of the usefulness of the meeting was the instigation of a solution to monitor stepper motor errors via their reporting within the FITS headers. And as a real bonus, CASU brought back some examples of engineering data from a 2kx2k Raytheon detector already delivered to RAL and were pleasantly surprised by the quality of the data. Many useful and fruitful discussions regarding data capture and aquistion were had and overall impressions of the IRAC controllers + Raytheon detectors were very favourable. There was some quite a lot of discussion regarding the Data Interface Dictionary. CASU agreed to supply a draft version of this to RAL/ATC within the next 2 weeks. <<<< 4. JRL's visit to JAC JRL will be at the JAC from September 29th to October 5th inclusive. The purpose of this visit is to progress a number of outstanding issues that have proven impossible, or impractical, to do remotely. JRL and JAC staff held a conference phone call last week to detail plans for the visit. The main one being to install the CASU WFCAM DR pipeline on a JAC machine and demonstrate the functionality of system up to the level of milestone 4. A further aim will be to ensure that JAC staff are able to check the CASU system out from the CVS, build it, and exercise it with UFTI data. There was also some discussion on the ORAC-DR infrastructure the CASU WFCAM DR pipeline is using. JRL confirmed that WFCAM ORAC-DR uses the ORAC_ generic FITS headers and agreed to look into moving the MEFITS header reader code into the Astro::FITS::Header module rather than keep this generic code in ORAC-DR. Since this was an unexepected imposition, JRL asked JMI to help out with this task and will take the modified code with him. Further discussions with JAC staff will be continued at ADASS, where JRL, FE and TJ will all be present. JRL will also sort out various UKIRT Archive and OMP database issues regarding updating WFCAM FITS headers in Cambridge with observer comments and other ancilliary information; and discuss aquiring Sybase replication licences at both ends for automating DB mirroring. It was thought that this visit would also be the best opportunity to discuss several other issues raised in earlier action items. 5. Progress on deliverables for Quarterly report MJI briefly described his astrometric distortion report. It was noted that for WFCAM the spatial distortion would be significantly wavelength dependent. It was note that an "r-cubed" radial distortion model gives a very good fit to the ray-traced distortion pattern and that further work on characterising the distortion can only be done using real on-sky data. One of the many conclusions from the report is that there is approximately a 10" diameter limit to dithering patterns for WFCAM before non-linear resampling at the detector level is required. For VISTA, no practically useful dither is possible without non-linear resampling. It was also noted that the scale distortion has an impact on photometric measurements. For WFCAM the size of the effect varies from 0% to 1.6% ie. comfortably within a +/-1% overall systematic calibration error budget. However, for VISTA the size of the effect varies from 0% to 3.5% and without correction would overflow the entire systematic photometry error budget. Both "problems" for VISTA will require a more sophisticated version of the pipeline to deal with them. This has already been planned for and will be incorporated as an option in Version 3. of the WFCAM pipeline (ie. Version 1. of the VISTA pipeline). A few minor changes for clarification of some points were requested and these will be incorporated prior to release on the documentation web page. <<<< DWE described his interleaving report. In addition to what was reported last time some 3x3 interleaving tests have been carried out. These show an improvement at the bright end over 2x2 interleaving, however it is anticipated that in real data additional effects will be present that will also limit the bright end positional accuracy. MJI suggested that the profile fitting software written for DIVA tests could form the basis for PSF fitting tests on this data. However, he was of the opinion that straightforward profile fitting of hedgehog-like PSFs on interleaved data would not work very well and that in the end simultaneous PSF fitting to each individual component frame may well be the best solution. The slightly revised version will be put on the public web pages. <<<< There was also some discussion regarding why interleaving currently affects the detection limit. When real data is available it will be worth comparing results obtained from simply stacking all the frames, compared to processing them as interleaved frames. Interestingly, the hedgehog-like frames are not visually appealing either ("look like shite" was one comment). It is a moot point whether interleaving real data is worthwhile - we will see. The deliverables from Q3 were then discussed in detail. As usual we all need to send in a summary for the Q3 report and suggestions for new deliverables for Q4 to STH and MJI by Thursday evening. <<<< 6. AOB Filling in .away: we were all encouraged (again) to fill in our .away files regularly and preferably in advance. Each document we have produced has to be allocated a document number. STH will write a document describing the document numbering scheme and keep track of the numbers. <<<< Amazingly, we have received our contract renewal letters. Except PSB, but he's already got one anyway. Continuing Actions ------------------ STH check Sandy Legget's data and (probably) send in a request for more data. STH write context intro for simulation report STH extend the number of fields that he has established for WFCAM to the south for use by VISTA. It was decided that this should be a Q4 task with a timescale of 1 month. DWE will monitor the visibility progress of CASU on IoA web pages New Actions ----------- JRL during JAC visit, find out from AA about the UKIDSS Survey Manager appointment on Hawaii. JRL discuss the setting up of the photometric standards fields within the characterization plan with Paul Hirst and Andy Adamson during visit to JAC. STH pass on DWE's additions to the characterization plan to JRL who will JRL raise them during his JAC visit. DWE remove the filenames from the documentation web page and add the STH document numbers and reformat to be more user friendly MJI contact NCH for more details on the ROE disc problems and plans for alternative Linux systems. PSB write real draft version of Data Interface Dictionary document and MJI supply to RAL within 2 weeks. JRL JRL get as far as Milestone 4 by the end of JAC trip. JRL pass on CASU additions to the characterization plan. MJI make minor changes to astrometric distortion report and place on web DWE place interleaving report on public access side of web ALL send in a summary for our Q3 report and new deliverables for Q4 to STH and MJI by Thursday evening. STH provide a document number for each released CASU document and write a document describing the scheme. Also keep track of these numbers.