Discussion - Survey Design Survey product equation: #fields = fld/nt x useable x (%xnights/yr) x years = 4 x 0.5 x (0.75 x 13 x 18) x 3 = 4 x 0.5 x 175 x 3 = 1050 Fields to be observed = = 1163 (difference is an extra 4 months of observing) Duration: 1360 fields will take until end 2005 How can this timescale be shortened?

Survey Design (2) More fields / night? – Could we achieve 5 flds/nt? (shorter exposures? quicker change-overs?) But stress on observers, quality control? Higher useable fraction? – El Nino! If 0.5 is 0.6 then 1260 fields done in 3 years – Fewer instrumental problems would also be...instrumental More nights per year? – Higher fraction of time? (85% allocation would do it) Longer duration? – Perhaps possible, but scientifically undesirable

Survey Design (3) Current bottlenecks… – Partial/missing input samples: what is the deadline for including samples in the survey (very soon surely?) – Morphological classifications: NIR photometry insufficient, but we have SuperCosmos B + R, so can use optical/NIR colours or even visual morphologies (who will do this?) Other issues… – Standard stars for  measurements? Needed? If so, which, how many, how to obtain? – Order to observe fields: by Dec strip? Galactic latitude?

Discussion - Survey Operations Survey observations… – Quality control: top priority! Need immediate checks on spectral quality - S/N, PSF; what else? Who should do this (observers? astronomers?) Should subjective measures have names attached? – Observing support: what are the needs for visiting observers from the survey team? How best deployed? Survey reductions… – Checks on 6dfdr: Careful examination of spectra to check reductions is needed - who, how, when? – Optimization of 6dfrunz: are needed - who, how, when?

Survey Operations (2) Survey dataflow (see chart)… – Where are the weak points in this plan? – Where are the bottlenecks? – Is information getting to where it’s needed? – Are the resources sufficient for each task? – What is missing?

Survey Operations (3) Current bottlenecks: – Data reduction backlog: need all data to May 2002 reduced well before Early Data Release in Sep 2002; can this be done by under current arrangements? Are extra resources needed? – Redshifting backlog: at present ~1hr/field, 150 fields to do, ~3 people working on it volunteers welcome!); tuning of 6dfrunz (esp. splicing V+R spectra) would greatly reduce time/field; reasonable to expect 15min/fld – Velocity dispersion: pipeline still to be written, much work still to do (dispersions NOT available for the EDR).

Discussion - Survey Database Database content… – Redshift survey: all input source catalogue parameters, spectroscopic observation parameters, postage stamps in as many bands as possible, spectra (and variance array), redshifts and associated info… – Velocity survey: D n -  parameters, distance, pec.vel., etc. – What additional parameters should be included? (what about useful/rationalized subsets? what about federation with external datasets?) – Need to deal with null values in catalogue parameters.

Survey Database (2) Database interface… – Does the 2dFGRS database provide a suitable model? (albeit with a number of functional improvements) – Essentially a collection of FITS files with all information on each object in headers/images/spectra plus an SQL database of all parameters with a WWW interface and multiple extraction methods (text, HTML, FITS) – Serve images, spectra and user-specified subsets of complete catalogue (queryable on all parameters?) – What parameters should be indexed? (speed/storage trade-off)

Survey Database (3) Practicalities… – Location: at WFAU in Edinburgh (what about mirrors?) – Manpower: what effort is available? is it sufficient? – Data release: who will be responsible for this?

Discussion - Science Exploitation Data releases… – Early Data Release in Sep 2002 (all input catalogues plus limited set of spectra/redshifts for testing); should this be limited to survey team and AT PIs, or fully public? – Subsequent data releases: intention is to provide a public release every 6 months; can we provide a shorter timescale for AT PIs? – Velocity survey data (distances, peculiar velocities) are much more difficult, and will lag significantly - t.b.d. – Format: releases (except final) will be WWW-only

Science Exploitation (2) Students and postdocs… – Heath Jones, Lachlan Campbell, Tom Mauch, Daniel Burkey – Do we need more? Are others expected? Avoiding/resolving scientific overlaps/conflicts (also identifying productive collaborations/synergies)… – Especially important for students/postdocs – Communication the key! Survey participants need to spell out proposed areas of research, identify potential overlaps and negotiate solutions - how best to do this? (team exploder, ‘who is doing what’ WWW page, meetings…)

Science Exploitation (3) Other issues… – Detection of optical Sne in 6dFGS spectra - can we do it in real time? (perhaps include a SN template spectrum?) – Detection of Galactic emission/absorption is common at low |b|; is this of scientific interest? If so, what do we have to do to make these detections useful?