Bent Gregorian Technical Observing Plan: April/May 2009

Daytime/Closed-Dome TCS SW Tests (B24):

  • Day 1, 09:00 to 15:30: This will involve changing aspects of the building's state.
  • Day 2, 09:00 to 15:30: Same. This day may requiring moving the telescope in the 2nd half.
  • Day 3, 09:00 to 15:30: Same. This day will include moving the telescope.

Execute TCS startup checklist every night
  • Complete by sunset - 1hr
  • Include mount encoder resets each night.
  • Reset collimation model = clear all active/global offsets
  • At end of startup, issue a standard preset:

Startup pointing & collimation correction (10 minutes):
  • Use WT10 or ACT pointing stars with IRTC
  • Select target at mid EL (50-70 degrees)
  • Preset in PARALLACTIC/TRACK mode:
    With AGw: pointto starname gs=0 Tel="ACQUIRE" PA=0 PAM-
    With IRTC: pointto starname gs=0 Tel="TRACK" PA=0 PAM-
  • If using IRTC, turn on "movie" mode
  • Have TO run "ptspiral" from lbtmu01 and
    • ^C when the star appears on the chip
    • Adjust IE and CA to center; manually focus if necessary
  • Preset in POSITION/ACTIVE mode on axis (Persson std)
  • Allow system to collimate (WFS<400nm rms)

On-sky TCS SW Tests (B24)
  • Need input from TCS group!

Verify or Update Collimation Model [2hr + reduction + 1 iteration]
  • Prerequisites:
    TELESCOPE IN THERMAL EQUILIBRIUM!
    DECENT SEEING (less than 1.25 arcsec FWHM on guider)
  • Use collimation sources, Persson standards, off-axis guide stars.
  • Set PSF to send collimation updates to M1.
  • Verify M2 is at its nominal position
  • Observe sources: 25(15) < EL < 87 if possible
    1. pointto sourceID gs=0 Tel="ACTIVE"
    2. Allow system to collimate: WFS<400nm rms
    3. takepic 2.0 to record mirror information
    4. Repeat steps 1-3 as needed to cover EL-space
  • Observe minimum 1 full cycle through EL range, 12 sources,
    Prefer two cycles, 20+ sources.
  • Generate new collimation model (J.Hill?)
  • Implement new collimation model

Verify or Update Pointing Model [2hr + reduction + 1 iteration]
  • Prerequisites:
    TELESCOPE IN THERMAL EQUILIBRIUM!
    Using new collimation model from previous step
    Re-measure mechanical rotator center coords on IRTC
    • Take pair of TRACK mode images rotated 180 degrees apart
    • New rotator center: X Y
  • Update collimation (not split, M1 only) at EL 50-70 degrees
  • Update pointing, repeat with ptspiral as needed below
  • Use WT10 and ACT stars
  • Turn on pointing log in PCS GUI
    Filename = ____________________
  • Use /home/LBTO/POINTING/Pointingstars5 to schedule
    1. In your working directory on an observer workstation:
      cp ~LBTO/POINTING/* . to copy program files
    2. Type ./Pointingstars5 at linux prompt to run program
    3. Enter the sequential reference field number [1-88]
    4. Preset to the source listed, TRACK mode, take 10s exposure.
    5. Repeat steps 2-4 for at least 24 points, 48+ would be better.
    6. If Pointingstars5 returns a 999, skip this star and try again later
  • Stop pointing log in PCS GUI
  • Generate new pointing model (D.Thompson)
  • Implement:
    • Copy to ~telescope/TCS/Configuration/PCS/
    • Update LUCIFER entry for LEFTPOINTINGMODEL
      in PCSInstrument.conf
    • Re-authorize LUCIFER on IIF GUI to read in new pointing model
  • Test new pointing model

Execute Jesper's AGW Calibration Plan (CAN#NNNNNN)
  • Re-measure AGw hot-spot location on CCD [1hr]
  • Update AGw encoder zeropoints to put the hotspot on the rotator axis [1hr]
  • Re-measure AGw pupil position, update IDL and GCS as needed [1hr]

Field Aberration Stability [6 hours]

New AGw calibration set [4hrs + 2 repetitions]
  • Calibration obtained on UT20090427, take verification data:
  • Use StoneMagw or StoneLagw fields here for high-precision positions
  • Observe at fixed PA
  • Important to have a good uniform coverage of the (x,y) space
  • ~30+ different positions
  • Repeat at different PA's to fill XY space if needed
  • Use takeseq to get 20+ total seconds of integration at each position
  • Run "getdat" on agw-control computer to record AGW coordinates

Offset testing [4hrs + 2 repetitions]
  • Requires good AGw transform!
  • Accuracy and repeatability of telescope+AGw positioning.
  • Test on small (2-5") and medium (~25") offsets
  • Use IRTC task "dice5", do 30x2sec, loopN=5

Vibration/jumps [2hrs on calm night and 2hrs on windy night]
  • Accelerometers will always collect data during technical run
  • Take dedicated IRTC fast imaging during varying wind conditions.

Open-loop tracking test (is this not also a collimation stability test?) [3 hours]
  • Collect open-loop tracking performance data to better understand cause of guiding jumps.
    • ACTIVE mode preset, allow to collimate
    • Turn off guiding updates on PCS so GCS continues to collect guider images
    • If desired, turn off WFSing on PSF so GCS continues to collect WFS images
  • Plot wfs rms and guider fwhm vs time since last offset
  • split between shorter and longer offsets.

Optimize Guiding Gain Factor [4 hrs]
  • Minimize guiding residuals

Demonstrate Guiding/WFSing to R=18 mag [6 hrs]
  • Plot rms vs. magnitude [M92astrom has a good selection of magnitudes]
  • May require WFS operating to 120s exposures
  • Review exposure time scaling algorithms ASAP

Quantify/Track Technical Downtime and Observing Efficiency

Re-Calibrations needed with LUCIFER:

* Verify/Re-calibrate Collimation Model
* Verify/Re-calibrate Pointing Model
* Orientation to N (accurate! <0.02 degrees)
* Verify/Re-calibrate AGW transform
* Test Large-Scale (0.5-4.0 arcmin) Offset Accuracy and Repeatability

Staffing for Observations

All dates and times in UT, April/May 2009

UTDateUT Instr Observers Start/End/Down Times Comments
24 IRTC AR, MP, JHe, SW S: E: D:  
25 IRTC AR, MP, JHe S: E: D:  
26 IRTC AR, MP, JHe S: E: D:  
27 IRTC DT, JHe S: E: D:  
28 IRTC DT, JHe S: E: D:  
29 IRTC RG, JHe, (DT) S: E: D:  
30 IRTC RG, JHe, (DT) S: E: D:  
01 IRTC RG, JHe, (DT) S: E: D:  
02 IRTC DT, JHe S: E: D: Contingency
03 IRTC DT, JHe S: E: D: Contingency

AR: Andrew Rakich
MP: Marco Pedani
JHe: Jochen Heidt
DT: Dave Thompson
RG: Richard Green
SW: TCS group

-- DavidThompson - 22 Apr 2009
Topic revision: r10 - 07 May 2009, JohnHill
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