LUCI2 Seeing-limited Commissioning Tasks

The team:
JHeidt (LSW): Lead, coordination + everything
WSeifert (LSW): Co-lead, coordination + everything
DKuegler (LSW): Scriptor, data reduction + analysis (remote)
IStilz (LSW): Acq. and alignment tool (remote)
PBuschkamp (MPE): MOS
HGemperlein (MPE): MOS
JPanuduro (MPIA): Detector (remote)
KPolsterer (HITS): Software
APramskiy (AIRUB): Software
DThompson (LBTO): Support obs, data reduction + analysis, anything else tbd
MEdwards (LBTO): Support obs, data reduction + analysis, anything else tbd
OKuhn (LBTO): Support obs at a later stage

Executive Summary Block as of January 31 2014. The "status" indicates on whether the data have been taken
and/or the tests concluded but not on whether the data taken have been analysed
Times given refer to amount to finish the task excl. overhead

DAYTIME (Closed Dome) Tests . . . . . . . . . . . . .
Test Status Time   Test Status Time
LUCI2 re-installation on telescope done     Grating Tilt (Lambda-V) calibration done  
SW communication with instr./TCS done     Detector tests (RON, DC, background) done  
MOS tests done     Detector tests (linearity, crosstalk, persistence) done  
General function tests done     Flatfields calibration unit done  
Internal focus determination/image quality done     Active flexure compensation open 5hr
General reproducibility tests done     FITS header check ongoing  
Spectral alignment check done     LUCI Aux cryostat - Xchng tests 15 Oct done  
Spectral resolution / grating dispersion done     Fine tuning electr./cryo/vacuum syst done  
Field centering and pupil alignment done     Interlock and alarm functions done  
FlexComp - calibration & verification done     Rotational balance of instrument pending  

NIGHTTIME (On Sky) Tests . . . . . . . . . . .
Test Status Time   Test Status Time
Instrument operations done     System efficiency, phot. ZPs, SNR done  
Observing sequences done     Photometric transfer coefficients BB filters done  
Telescope focus done     Image movement due to flexure done  
Pupil imaging done     Acquisition and alignment procedures done  
Orientation on sky done     Image quality spectroscopic modes done  
Guide probe transformation - calib & verifiy done     Active flexure compensation open 10hr
Offsets: accuracy, stability, ctr of rot'n done     Crosstalk & persistence done  
Image quality imaging mode done     Instrumental background done  
Image scale all cameras done     Temperature stabilization of instrument done  
Image distortion all cameras done     Temperature stabilization of detector done  
Ghosts, scattered light done     Twilight flats done  

DAYTIME (Closed Dome) Tests . . . . numbers in brackets refer to commissioning plan version 2.1. . . . . .
  • LUCI2 re-installation on telescope.
  • SW communication with instrument and TCS (7.1.1)
  • MOS tests (7.1.2)
  • General function tests
  • Internal Focus determination / image quality (7.1.6)
  • General reproducibility tests (7.1.3)
  • Spectral Alignment Check
  • Spectral resolution / grating dispersion (7.1.7)
  • Field centering and Pupil alignment (7.1.5)
  • Flexure compensation - calibration and verification (7.1.4)
  • Grating Tilt (Lambda-V) calibration
  • Detector tests: RON, DC, background (7.1.11, 7.1.13, 7.1.14)
  • Detector tests: persistence, linearity (7.1.12, 7.1.15)
  • Flatfields calibration unit (7.1.10)
  • Active flexure compensation (7.1.16)
  • FITS header check (7.1.17)
  • LUCI Aux cryostat - Mask exchange tests scheduled for 15 Oct
  • Fine tuning electr./cryo/vacuum system (7.1.8)
  • Interlock and alarm functions (7.1.9)
  • Rotational balance of instrument (7.1.18)

NIGHTTIME (On Sky) Tests . . . . . numbers in brackets refer to commissioning plan version 2.1.. . . . . .
  • Instrument operations (7.2.1)
  • Observing sequences (7.2.2)
  • Telescope focus (7.2.3)
  • Pupil imaging (7.2.4)
  • Orientation on sky (7.2.5)
  • Guide probe transformation (7.2.6)
  • Test offsets, accuracy & stability, center of rotation (7.2.7)
  • Image quality imaging mode (7.2.8)
  • Image scale all cameras (7.2.9)
  • Image distortion all cameras (7.2.10)
  • Ghosts, scattered light (7.2.11)
  • System efficiency, phot. ZPs, SNR (7.2.12)
  • Photometric transfer coefficients BB filters (7.2.13)
  • Image movement due to flexure (7.2.14)
  • Acquisition and alignment procedures (7.2.15)
  • Image quality spectroscopic modes (7.2.16)
  • Active flexure compensation (7.2.17)
  • Crosstalk & persistence (7.2.18)
  • Instrumental background (7.2.19)
  • Temperature stabilization of instrument (7.2.20)
  • Temperature stabilization of detector (7.2.21)
  • Twilight flats (7.2.22)

On-telescope day-time (closed dome) calibrations:

Scripts for closed-dome activites are placed in folder daytime_com at the LUCI machine

LUCI2 re-installation on telescope, duration 1.0d, scheduled for Oct 23

Successfully done by LBTO on Oct 23

SW communications with instrument and TCS, duration 16hrs

Item: Test of the communications of the control server with the instrument, the detector, and the TCS
Responsible: K. Polsterer, A. Pramskij
Phase: At time of installation at the telescope to be done until Nov 9
Procedure: Check of the communication lines; command interpretation etc.
Remarks: To be optimized during the nighttime observations. Does usually not interfere with telescope work.
As many as possible tests will be performed while LUCI2 is in the lab and before.
As of Jan 08: mostly been done, some fine-tuning required, stability must be improved

MOS mask exchange Tests, 2* 6hrs, scheduled for Oct 24

Item: Tests of the mask exchange for all instrument rotation and tilt
Responsible: PBuschkamp
Phase: As early as possible (Oct 24)
Procedure: Exchange MOS mask with the rotator at different position angles.
Remarks: For safety reasons, LBTO support needed for rotation/tilt of the telescope.
Successfully done on Oct 24

General function tests, duration 4h, scheduled for Oct 24

> Basic instrument function tests:
  • Stop SW / Re-start SW (optional, restarted in move to telescope)
  • Repeat at ROT ~ 341, 221, 101 degrees the following:
    • Camera Wheel: Init; move several times between N1.80 & N3.75 camera
    • FW 1 & 2: init, move both wheels front/backwards movements
    • Grating Unit: init, select all gratings/mirror
    • Grating Tilt: set voltages 0V, +-1V
    • Detector focus: move steps to reach neglim & poslim, note # of steps
    • PV: init and move in/out
Responsible: WSeifert, JHeidt
Done in the period Oct 24 - 30

Internal focus determination, duration: 1h

Determine detector focus for BB-filters and 1-2 nB-filters for crosscheck with
relative offsets derived for acceptance test report.
Responsible: WSeifert, JHeidt
Jan 08: Done for all BB-filters and a few nB-filters with N3.75/1.8 cameras

Image quality

Item: Point spread function (PSF, as a measure for image quality) over
the field with N3.75 camera for all broad-band filters.
Responsible: WSeifert, JHeidt
Phase: To be done until Nov 9
Procedure: Take images with Optic Sieve mask.
Remarks: Images from internal focus determination may be used.
Full check under operation during night is required.
Jan 08: Done for all BB-filters and a few nB-filters with N3.75/1.8 cameras

Function reproducibility tests, duration 20h

Item: Measurement of the reproducibility of the moving functions of the instrument.
Responsible: JHeidt, WSeifert
Phase: Until Nov 9
Procedure: Measurements of the reproducibility of calibration unit, grating positioning,
grating tilt, camera exchange, detector focus, mask exchange etc. under various gravity
directions. Compare to numbers in acceptance test report (should be equally good).
Remarks: LBTO support needed for rotation/tilt of the telescope.
Jan 08: Done

Spectral resolution and grating dispersion, duration 1h

Item: Evaluation of dispersion and resolution via line width
Responsible: J. Heidt
Procedure: Taking spectra of the wavelength calibration lamps with all cameras to determine spectral resolution.
Compare with results from acceptance test report.
Remarks: Data from spectral alignment check can (partly) be used
Jan 08: Done

Field centering and pupil alignment, duration 5hrs

Item: Alignment of re-imaged telescope pupil
Responsible: WSeifert, DThompson
Phase: Until Nov 9
Procedure: Observe pupil with pupil viewer optics.
Align the pupil. Check for shape and homogeneity.
Prerequisites: Done with N1.80, PV optics and K filter.
Remarks: Based on a procedure developed by D. Thompson. Field centering done as usual using FM4
Successfully done on Nov 9, needs to be checked regularly

Internal flexure, duration 2*8hrs

Item: Measurement of the internal flexure of the instrument
Responsible: WSeifert, DThompson
Phase: At least N3.75/ima and N1.8/g210 MUST be done by Nov 9
Procedure: Measurements of the internal flexure of the
instrument for N3.75 and N1.8 camera in imaging and spectroscopic mode.
Remarks: Input for flexure compensation. Two data sets, one for measurement,
one for verification of flexure compensation.
Finished on Nov 13

Grating tilt (lambda-voltage) calibration, duration 10h

Telescope: @Zenith, Rotator enabled, Lights OFF in dome
LUCI2: Calib unit in beam, LS0.75_450um slit, grating tilt loop closed.
Done for N1.80-camera only but for all gratings/orders
Rough calibration should be in place until Nov 9, good calibration until Dec 12
Responsible: JHeidt
Finished on Nov 30

Detector tests: dark current, duration 0.5hrs, daily

Item: Measurement of the dark current of the detector and compare to measurements from acceptance test (0.01 e$^-$/sec/pix).
Responsible: JPanduro, DThompson
Phase: During all commissioning phases, first set to be taken until Nov 9.
Procedure: Measurements under low background conditions, i.e. lights in dome off.
Prerequisites: Setup: blind mask, blind/blind filters
Remarks: To be done preferably before any flatfield and in connection with
background determination. Be careful with persistence!
Permanently ongoing

Detector tests: parasitic light - background, duration 0.5hrs daily + 1 full day

Item: Determination of the level of background light entering the instrument.
Responsible: JHeidt, JPanduro
Phase: During all commissioning phases
Procedure: Take long exposures with blind mask, clear/K filters. Compare with true dark exposures.
Perform the test with enclosure lights both on and off.
Remarks: To be done preferably just before any flatfields
The full day measurement can be done at the weekend w/o LBTO support
So far on obvious sign of parasitic light, may be skipped. DThompson detected vertical banding on images which may be due to problems with ROE. Needs to be investigated

Detector tests: electronic noise from environment, duration 4hrs

Item: Determination of detector electronic noise in the telescope environment.
Responsible: JHeidt, JPanduro
Phase: To be done during the first three runs
Procedure: Move telescope, rotate dome, switch lights on/off during exposure of the detector and determine electronic noise
Remarks: Needs support by LBTO for rotating the dome, moving telescope etc. ; schedule TBD with LBTO
As above

Detector tests: linearity, duration 2hrs

Item: Determine coefficients pixel-by-pixel to correct science and calibration frames
for non-linearity of the detector across the entire dynamic range.
Responsible: JPanduro, DThompson
Phase: Until Nov 15
Procedure: Take images with increasing illumination from lowest level to saturation.
Still open

Detector tests: crosstalk and persistence, duration 1h

Item: Estimation of crosstalk and persistence for the detector.
Responsible: JPanduro, DThompson
Phase: Until Nov 15
Procedure: Take images using a new ``persistence mask''. Compare with results from acceptance test report.
Prerequisites: New ``persistence mask'' delivered by the time daytime commissioning starts.
Still open

Flatfields with calibration unit, duration 10hrs

Item: FF accuracy using twilight and the calibration unit
Responsible: Team, (LBTO)
Phase: All commissioning phases, whenever there is time
Procedure: Averaged sky and screen flats are compared. Homogeneity of illumination
and exposures times are evaluated. Done for all broad-band filters and for as many narrow-band
and medium band filters as possible (order of importance TBD).
Duration: Each day 2x 0.5 ,hour of twilight; 10 ,hours of daytime
Prerequisites: LBT at our disposal, photometric night; target: twilight sky
Remarks: Once the first on-sky commissioning is completed, LBTO may take flatfields during science time in parallel.
Flats in all filters have been taken with the N3.75-camera Illumination is very inhomogeneous between lamps (on the order of 40%)

Active flexure compensation, 5hrs

Item: Initial tests for active flexure compensation. Verification of procedure.
Responsible: Team
Phase: Until Dec 12
Procedure: Same as for internal flexure
Remarks: Novel, may require fine-tuning.
Still open

FITS header check, duration 0h (offline)

Item: Check correctness of fits header of data taken (day/night).
Responsible: Team
Phase: During all phases
Procedure: Inspect fits header of data taken throughout the activities.
First iteration by DThompson on Nov 22

LUCI2 aux cryostat exchange, duration 1d, scheduled for Nov 15

Full test of LUCI2 aux cryostat exchange.
Responsible: PBuschkamp
Successfully done Nov 15

Fine tuning of electronics/cryo/vacuum systems, 1h daily (early phase)

Item: Fine tuning of the electronics settings and the cryo/vacuum system
Responsible: MLehmitz, WLaun
Procedure: TBD M. Lehmitz and W. Laun
Remarks: Access to platform might be necessary from time to time.
Still open

Interlock and Alarm Functions, duration 4hrs

Item: Tests of interlocks and alarm functions; functioning compability.
Responsible: MLehmitz, LBTO
Phase: At time of installation at the telescope
Procedure: Explicit HW tests of the interlocks (instrument internal IL and IL to LBT rotator)
Alarm simulation; check of direct and remote alarm signaling
Remarks: Access to platform is partially necessary. Needs LBTO support. Schedule TBD by LBTO.
Still open, but alarm "successfully" turned on a few times during com#2

Rotational balance of instrument label, duration 1h

Item: Determine (and adjust if necessary) the instrument rotational balance.
Responsible: LBTO (for measurement), team (for adjustment)
Phase: Time permitting as early as possible
Procedure: Perform a 360 degree torque measurement with the instrument on the rotator.
Will this ever been done?

On-telescope night-time on-sky calibrations:

Instrument operations

Item: Test of hardware and software proper functioning and reliability
Responsible: KPolsterer, APramskiy
Phase: During all commissioning phases
Procedure: Performance in all observing modes is evaluated under full SW control.
Demonstration of all reconfigurations.
Duration: Ongoing all the time
In principle done, fine-tuning going on

Observing sequences (software), duration 2hrs

Item: Check availability, setup time and proper functions of observing sequences.
Optimization of observing sequences.
Responsible: KPolsterer, APramskiy
Phase: 2 hours for initial checks; to be controlled during the whole commissioning time
Procedure: Setup instrument in all available modes (masks, cameras, filters, gratings, ...).
After Com#2: Imaging sequences work, spectroscopic ones in principle The latter needs to be optimized though

Telescope focus, duration 3hrs

Item: Instrument focusing (cooperation with telescope focusing via guider)
Responsible: Team, LBTO
Phase: First run with regular checks during all commissioning phases
Procedure: Use the Wunit to stabilize/step the focus while a focus sequence is taken
with LUCI2. Can be done with the N3.75 camera.
Prerequisites: Target: star(s). Internal focus LUCI2 determined and correct position of the
tertiary mirror determined before (the latter done by LBTO). Can be done before LUCI2 is installed.
Remarks: Conventional or using procedure proposed by D. Thompson (TBD).
Done on Nov 11

Pupil imaging, duration 2hrs

Item: Homogenous illumination of re-imaged telescope pupil
Responsible: Team
Phase: One check within each commissioning run.
Procedure: Observe pupil with pupil viewer optics. Check for shape and homogeneity
Prerequisites: star
Remarks: Verification of pupil alignment based on a procedure developed by D. Thompson.
Done on Nov 9

Orientation on sky, duration 1h -> 3hr (need many fields, verification)

Item: Determine N-S and E-W orientation of FOV and set the rotator zero point for north direction.
Responsible: Team
Phase: As early as possible
Procedure: Take image of star cluster and determine the orientation. Set the rotator zero point for
North direction up/down in the TCS.
Prerequisites: star cluster
Done during Com#1

Guide probe transformation, duration 2 * 3hrs

Item: Determine guide probe transformation. Determine center of rotation of the instrument rotator in guide probe coordinates.
Responsible: LBTO
Phase: As early as possible
Procedure: Take images of astrometric stars spread across the AGw patrol field at various PA.
Prerequisites: Good seeing (< 0.8'')
Remarks: First set of data taken to derive guide probe transformation, second set of data for
verification. May require a second iteration.
Done during Com#2, potentially a quick-check required during com#3

Test Offsets, accuracy & stability, determine center of rotation, duration 6hrs

Item: Determine sign for size and sign for telescope offsets; determine center of field for rotation;
determine pointing accuracy; test guiding accuracy and stability; test jitter-offset sequences
Responsible: Team
Phase: As early as possible
Procedure: Take image of star(s) and run the procedures for offset, guiding etc. Evaluate the resulting accuracies.
Prerequisites: star(s) cluster
Mostly done

Image Quality under Seeing Limited Observing Conditions, duration 5hrs

Item: Point spread function (PSF, as a measure for image quality) over
the field with N3.75 camera for all broad-band filters.
Responsible: Team
Phase: First run, to be regularly checked during all commissioning phases
Procedure: Imaging of star clusters during period of (very) good seeing, distributed over
the whole FOV covering the whole instrument wavelength range. Different azimuth and elevation angles.
Prerequisites: Target: Star cluster
Remarks: Can be done together with telescope focus.
Mostly done

Image Scale for N1.8 and N3.75 cameras, duration 2hrs

Item: Image scale for N1.8 and N3.75 cameras
Responsible: Team
Phase: First run, to be regularly checked during all commissioning phases
Procedure: Imaging of stars with precisely known angular distances in N1.8 and N3.75 modes.
Take into account scale variation caused by the telescope, if measurable
Prerequisites: Stars with astrometric positions within the N1.8/N3.75 FOV
Remarks: Can be done together with image quality.
Mostly done now

Image Distortion of N1.8 and N3.75 cameras, duration 4hrs

Item: Astrometric calibration over the field, as a function of filter setting for the N1.8 and N3.75 cameras
Responsible: Team
Phase: First run, some time to be re-checked in later commissioning phases
Procedure: Take image of astronomic star cluster and derive distortion
Prerequisites: Target: Star cluster with astrometric star positions.
Remarks: Can partially be done with image quality.
Mostly done, a globular cluster with good? astrometry was observed during com#2

Ghosts, Scattered Light, duration 3hrs

Item: Determination of ghost intensity and scattered light level in the instrument
within the telescope environment
Responsible: Team
Phase: First run
Procedure: Imaging with all cameras, a subset of filters (TBD) and gratings.
Take series of images with changing integration times. Evaluate side lobes of
PSF at low intensities. Take some images with the star at the field center
and with the star at 2/3 of the field.
Prerequisites: Bright star without an additional bright star in FOV
Done during com#2

System efficiency, Photometric Zero Points, SNR, duration 9hrs

Item: Telescope plus instrument efficiency in imaging and spectroscopic modes
Responsible: Team
Phase: All commissioning phases
Procedure: Compare expected count rates (including atmosphere) with the
observed ones for several standard stars of different colors. Determine efficiency,
zero points and SNR resp. T_exp for given T_exp resp. SNR. To be done for
broad-band and narrow-band filters and available gratings.
Determine radial photometric gradients, if any.
Prerequisites: Photometric observing conditions.
Target: photometric standard star field(s).
Remarks: Spectra with 210zJHK grating to determine throughput of the instrument
should be taken with high priority during the first commissioning run.
Done for all filters/N3.75 camera and bb-filters/N1.8 camera, tbredone during com#3
Checked for photometric gradient across detector in K and Br_gam

Photometric Transfer Coefficients for Filters, duration 6hrs

Item: Determination of photometric transfer coefficients (zJHK and Ks)
Responsible: Team
Phase: All commissioning phases
Procedure: Observation of standard stars in the zJHK and Ks filters until
the necessary accuracy is reached.
Duration: Initially 6 hrs of nighttime; the transformation will be
improved with time by additional observations.
Prerequisites: Photometric observing conditions.
Targets: photometric standard stars.
Mostly done, additional data tbtaken during com#3

Image Movement due to Flexure label, duration 4hrs

Item: Evaluation of image position for all rotation and tilt angles of the instrument
Responsible: Team
Phase: All commissioning phases
Procedure: Take short images of the same star field at different zenith distances and hour angles
Prerequisites: star field
Remarks: This will account for differential flexure between AGw
and instrument in addition to the flexure internal to the instrument.
TBD during com#3

Acquisition and Alignment Procedures (Software), 10hrs

Item: Acquisition and Alignment in longslit and MOS modes (spectroscopy)
Responsible: Team
Phase: All the time
Procedure: Check software accuracy and repeatability of acquisition and alignment
Prerequisites: Star field
Remarks: New procedure, may require fine-tuning
Lots of time were spent on this during Com#1+2, works in principle fine-tuning required

Spectroscopic Modes (Longslit and MOS) under Seeing Limited Observing Conditions, duration 4hrs

Item: Image quality in spectroscopic mode, using N3.75 & N1.8 camera.
Responsible: Team
Phase: First run, to be regularly checked during all commissioning phases
Procedure: Take spectra with all gratings/orders in MOS mode.
Prerequisites: Target: Star cluster
TBD during com#3

Active flexure compensation, duration 10hrs

Item: Verification of active flexure compensation on-sky.
Responsible: Team
Phase: Not before Dec/Jan-runs
Procedure: Take spectra of point sources in all grating/orders using faint, intermediate
and bright night-sky lines for active flexure compensation. Verify long-term stability.
Prerequisites: Stars
Remarks: Novel, may require fine-tuning
Still open, ROM sample-up-the-ramp not yet implemented

Crosstalk and persistence, duration 3hrs

Item: Estimation of crosstalk and persistence for the detector
Responsible: Team
Phase: At a later phase
Procedure: Perform deep-sky imaging with N3.75 camera.
Prerequisites: Sparse sampled stellar field.
Remarks: Verification of daytime results.
TBD during com#3

Instrumental Background, duration 0hrs

Item: Determination of the level of background light entering the instrument
Responsible: Team
Phase: Once per commissioning run.
Procedure: Imaging with one camera, blind mask.
Duration: Nighttime/Daytime
Remarks: During periods of bad weather.
Ongoing

Temperature stabilization of instrument, duration 0hrs

Item: Check & verify temperature stabilization of the instrument.
Responsible: Team
Phase: During commissioning
Procedure: Set control for temperature and log temperature at 8 locations during the commissioning.
Prerequisites: ICE and software, logging system.
Ongoing

Temperature stabilization of detector

Item: Check & verify temperature stabilization of the detector.
Responsible: Team
Phase: During Commissioning
Procedure: Set control for detector temperature. Monitor temperature on short and long time scales during the commissioning.
Prerequisites: ICE and software, logging system.
Ongoing

Twiligt flats, duration each twilight under photometric conditions

Item: FF accuracy using sky flats and the calibration unit
Responsible: Team, (LBTO)
Phase: All commissioning phases
Procedure: Averaged sky and screen flats are compared. Homogeneity of illumination
and exposures times are evaluated. Done for all broad-band filters and
for as many narrow-band and medium band filters as possible (order of importance TBD).
Prerequisites: Photometric night; target: twilight sky
Remarks: Once the first on-sky commissioning is completed, LBTO may take flatfields during science time in parallel.
A good set of zJHKKs-flats was taken throughout Com#1, more data during com#2 nB/mB-flats taken: Br_gam, H2, FeII, P_beta, HeI, OH_1190 incl. some nB-filters during com#2* Ongoing

-- JochenHeidt - 31 Jan 2014
Topic revision: r38 - 01 Apr 2015, JochenHeidt
This site is powered by FoswikiCopyright © by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding Foswiki? Send feedback