WEAVE: Data Flow Operational Stuff

Operational Walkthrough

Definition of target observations 1Science exec agrees default observing templates:

Fibre mode, gratings, calibrations, standard exposure time and number of exposures.

Science Teams define catalogues, one catalogue for each observing template. Unique identifier for each catalogue. Catalogues passed to SWG. Catalogues must be on a common astrometric reference frame (Gaia).SWG merge catalogues with common templates with overlapping sky areas to produce survey target lists, CNAMEs.SWG generate list of target fields (Field1.fld, etc, input xml files for configure) for each survey

Target fields may overlap, and should not contain more than a factor of ~2 more targets than there are fibres. Each target field mustcontain suitable guide stars and calibration targets.Auxiliary list of sources for each field should contain all known objects in the field. Configure will avoid these for sky placements.Fractions of targets to allocate to different catalogues and minimum number of sky fibres can be specified in the field definition. Xml file includes setup parameters for spectrograph, observation sequence etc, dither sequence for IFU modes etc…

Definition of target observations 2SWG runs configure on each field -> Field1.cfg

Should be run with most recently available set of positioner parameters. These are now effectively Observing Blocks (OBs)Each field should be available for a range of hour angles.Each MOS field must be configured for either plate A or plate B

OBs passed to OB Manager and sent to OB database and archivePositioner parameters will be updated after each instrument change (or perhaps monthly in the early phase of operations.)

Subset of OBs that are upcoming can be tweaked against changes in these parameters.

Additional OBs can be added to the database subject to exec approval, or from PI programs observing complete fields.Serendipitous PI targets must be included in the survey lists before the fields are configured. –Spare fibres remaining after configuration are unlikely to be useable for additional targets ‘on the night’…

WEAVE ObservationsQueue scheduler generates a list of OBs for the next night’s observations (at least one day in advance).AFTERNOON: some opportunity for calibration fields (salsa flats)

Operations staff setup starting configurations on both plates, expected mid-time of each observation must be specfied at this point. –May factor in weather expectations.N.B. 2nd field is already configured, so 1st field can be short (catchup?)High SN arc/flatfield frames can be taken for these fields. WLong detector darks can be taken during these setupsHealth check of instrument (check spectrograph focus), fill LN2 etc…

DOME OPEN: Twilight sky flats can be taken on 1st two fields, if desired. (assume a 5 minute overhead for tumbling the positioner.Pointing check and initial focus using positioner FPI.Bright calibration stars…Move to target position for 1st field. Take arc and flat.Observe 1st field when dark enough.

WEAVE Observation cycleDOME OPEN:

Observe 1st field when dark enough…✪Take arc at the end of observation (if required… -discuss)

Tumble positioner as soon as shutter closed, move telescope 2nd field postion. As soon as tumbler in position, start configuring 3rd field.Take flat and arc on 2nd field (dome could still be moving?)Acquire field and begin observations…continue around back to ✪Last field of night consider:

Arc/flat at end, rather than start?Field may be short, positioner not setting up, but should be parking fibres.Could use for catchup or part-OB

Can take twilight flats on the last two fields of the night (allowing 5 minutes for tumble overhead)Park telescope, set first field configuring for the next night, or at least park fibres.

Other things to noteAutoguider:

Star positions tracked through the fields of the AG bundles… movement due to differential refraction residuals after rotation correction.AG returns FWHM for each star and integrated counts as a measure of transparency variations during the observation.Poor seeing should trigger fallover to (e.g.LIFU observations)

QC: QC pipeline returns SN/magnitude for each fibre. QC analysis of first frame in a sequence should be ready before the 2nd frame has finished.

Allows in-principle adjustment of exposure times for poor transparency.

Overheads:Tumbler time ~ 2 minutes (1.5 minutes?). ~= Tel/Dome slew time-Tumble while reading out last frame!Readout time should be ~ 1 minute (90s?)Warmup time for lamps?

Other things to noteAcquisition:

Stars may not appear in guide fibres (due to telescope pointing accuracy?). Simplest option is to always unpark the FPI gantry after a tumble, survey the plate while the arc frame is reading out, and search for 3 guide stars to determine a mean offset in position and rotation, then acquire.

Time to switch from LR to HR modes: likely to be a few minutes, but no more. –Should avoid doing this in the middle of the night if possible.Moon Phase etc:

Should always be considering dark hours rather than dark nights…May need to be aware of bright planets for some observations –should be checking these as a matter of course.

Survey planning needs to consider RA pressure over full survey duration. Don’t want to finish up with 1 year of tidy-up observations to complete the sky coverage.

Effect of differential refraction on the astrometric distortion of the focal plane

Time pressure?

Drawn by

Date

Version Size

Title

Project

Location

Doc No

WEAVE

Survey Infromation and Data Flow

http://www.ing.iac.es/bscw/bscw.cgi

Chris Benn

A3

07 NOV 16 WEAVE-SYS-010-FIG1

1.3

KeyInformation flowScience data flow

Instrumentcontrol system

Observation scheduler

Quick look

WEAVE control

Data-acquisition system

CPS/L1 pipeline

APS/L2 pipeline

WAS (archive)

Data releases

On-island survey management team

Survey working group

Observer

On-island observation and QC database

Science teams

FITS headers

Housekeeping,and local

archive buffer

Users

PI WEAVE non-survey

programmes

Observation-block manager

Observation sequencer

Weather, seeing, etc.

Quick-look hardware

Quick-look software

CPS/L0 and operational repository

Fields (of fibre allocations)

Tiles (include all catalogue objects)

Input catalogue/s

Survey target lists

Observatory control system

Science processing and archiving

External dependencies

15th magnitude

22nd magnitude