From wjs@ast.cam.ac.uk Sun Oct 16 12:32:43 2005 Date: Fri, 1 Apr 2005 13:27:07 +0100 (BST) From: William Sutherland To: Tim Naylor Cc: Jim Emerson , Tim Naylor , Alastair Edge , paj@astro.livjm.ac.uk, pwl@star.herts.ac.uk, Steve Maddox , naw@ast.cam.ac.uk, s.j.warren@imperial.ac.uk, Malcolm Stewart , Mike Irwin , Peredur Williams , Nigel Hambly , Richard McMahon , Andy Lawrence , Simon Dye , Maureen Scott Subject: Minutes of 2nd VDUC meeting. Dear all, Apologies for delay - minutes of this meeting below. Thanks, Will. Will Sutherland (VISTA Project Scientist) wjs@ast.cam.ac.uk Mobile: +44 7889 396348 Office: +44 1223 337528 Institute of Astronomy, Madingley Rd, Cambridge CB3 0HA. ------------------------------------------------------- Minutes of 2nd VDUC meeting, Edinburgh, 21 Feb 05. ------------------------------------------------------- In attendance: M. Folger, N. Hambly, P. Lucas, S. Dye, T. Naylor (Chair), P. James, M. Stewart, N. Cross, E. Sutorius, M. Read, P. Williams, W. Sutherland, M. Irwin, J. Lewis, S. Berry, J. Emerson, A. Edge. Apologies: N. Walton, A. Lawrence. Review of Actions: FM1-3: Core radius. Ongoing. FM1-4: Report will be produced. FM1-5 : done FM1-7B: done FM1-7C: done FM1-7D: done FM1-8B: done FM1-9A: done. Report from Chair: Steve Warren has resigned from VDUC, and Simon Dye has taken his place. Steve will continue to give input via Simon. The VISTA UK URD v1.0 has been signed ; few responses have been received - a reminder will be sent requesting added use case examples for later versions. WFCAM status - see later. VISTA Board - Tim Naylor and Phil James agreed to attend this on an occasional basis when input on the pipeline is needed. Report from MJI on WFCAM : ---------------------------------- CASU didn't get laboratory WFCAM data as requested. On-sky data arrived Nov 05. Some analysis done, on 2 TB / 6 weeks worth of data, though less than hoped due to clash with VDFS + rolling grant + building move. The summit pipeline is stripped down for speed, does not do non-linearity correction, though is probably OK to assess photometric-ness of night. Summit pipeline delivers single-detector FITS files. At CASU, these are converted to MFE, ESO HIERARCH keywords added, Rice compressed, then copied to Garching. Non-linearity: 1 detector has opposite sign of this to other 3. The effect varies per channel, but not per pixel. Cross talk: is present, mainly between 8 channels in a quadrant. Persistence: is present, not well quantified yet. Fringing: none visible. Banding: this is the "curtain-like" structure visible, at level of +/-20 e-. It is different for every exposure, but repeats across quadrants. Partial fix in software. Stacked image looks good. Astrometry better than 0.1 arcsec rms: 2MASS errors appear to dominate this number. K, J-K diagram looks good. Throughput is slightly better than UFTI. Report from Jim Lewis: ----------------------------- Dark frames show `ramp' on one side of chip, aka Reset anomaly, much larger than the true dark current. This is stable for exposure times > 10 sec. Persistence: wavelength dependent. Cross-talk: is significant, see above. Issue with nearly-in-focus "crud" on field lens - varies with Moon. Report from Nigel Hambly: ----------------------------- SuperCos Science Archive now 5 TB, equivalent to a few years of WFCAM. Usage: 750 external queries, 35 cross-ID list-driven queries. Only 19 user feedbacks ( 7 of which UKIDSS ), generally positive. Hoping for more when WFCAM early data goes in. Hardware is mostly in place ready for WFCAM. Registration: it's up to AL + SJW + UKIDSS heads to decide who's authorised to access the Phase I data. VDUC recommended full UKIDSS consortium access to Phase II. >>> Action FM2-1 : CASU + WFAU to get WFCAM Phase I data into Archive by end March. >>> Action FM2-2: CASU + WFAU to deliver a "significant amount of data" into Archive by end May. Science verification data to be dealt with ASAP. Report from Simon Dye: --------------------------- The "banding" is at a level of 11 e- rms. There is a "random" large-scale component , plus sinusoidal small-scale. Reset Anomaly: needs to be scaled for shorter exposures. Persistence: worse after a filter change, especially the "flare" at edge of one chip. Suggest throwing away a few frames after each filter change. Y+Z issue: if 5 sec exposures are used, readnoise adds sqrt(2) to sky noise. Suggest not microstepping in Y and Z for LAS. Survey Definition Tool: to be available soon via JAC webpage. Choices of microstepping: clockwise / anticlockwise / figure-8 - TBD. Mike Irwin commented that pipeline cataloguing tests are awaiting some better imaging data. Open question - how useful is microstepping if there are short-term PSF variations ? >>> Action FM2-3: TN to contact UKIDSS survey heads to get them to coordinate with Simon Dye and CASU regarding technical details of the MSBs. >>> Action FM2-4: TN to request UKIDSS survey heads to present some results at the next meeting, late June / early July. >>> Action FM2-5: JPE to report outcome of VDFS review in due course. Report from Jim Emerson: ---------------------------------- Malcolm Stewart has taken over as VDFS Manager. Several VISTA talks were given at SPIE, Glasgow. ESO PDR and FDR have concluded successfully. The negotiations with ESO have concluded with a value of EUR 1M placed on the full VDFS pipeline + archive. The UK VDFS had a target FDR for 9 May (now moved to 16 Sep for external reasons). >>> Action FM2-6: All to email JPE with suggestions for review panel. This ended the meeting - next meeting TBC.