07-08 October 2008 On-sky TCS SW testing, Pointing Model

Observers: D. Thompson, J.Hill (Tucson), LUCIFER folks (N.Ageorges,W.Seifert, et al)
Software Support: C.Biddick, D. Cox in Tucson
Telescope Operators: D.Gonzalez-Huerta, W.Wack

Summary

Yesterday's collimation model improved things, but it is still out of focus donuts at low EL. Astrometric data taken for LUCIFER orientation (the two points are off by 0.05 and 0.22 degrees). Pointing model data taken and a new model generated, checked. LUCIFER data collected for photometric zero points and sky emissivity

Details

LUCIFER evening twilight flats?
  • Need to be open and ready to work at 5:15pm (sunset at 6:06).

Telescope ready at 5:35pm
LUCIFER twilight flat data obtained in filter Paschen Beta, done ~01:30

Correct initial pointing/collimation

BS9177 First preset - MSCPU error - rotator is not moveable. A better startup checklist would be useful for the OSAs.

Initial collimation on BS9177 (EL~69) shows 3" FWHM.

Check effects of M2 Motion on a Sphere

  • Clear M2 active optics, put all collimation on M1
  • Preset ACTIVE, allow to collimate
  • Take ~10 minutes of guiding images

lbtmu107:/tmp guiderimage000100 - 000192 (19:02MST + 10 minutes)

  • Split coma/focus to M2
  • Take ~10 minutes of guiding images

lbtmu107:/tmp guiderimage000224 - 000324 (19:15MST + 10 minutes)

  • Compare guider image motion at collimation updates vs. time since update

Also need dates from WFS images to correlate wfs updates and guider motion Data copied to /Repository/M2spheretest/

Analyzed 09Oct, see attached plot M2sphere.pdf. The squares are from data taken with all collimation going to M1, while the plusses are from data with coma and focus split off and sent to M2. There is no obvious difference between the two sets, so whatever is bring done with M2 it is _not_ significantly different than M1. I would note that this is different than the visual impression while watching the guider images.

Verify new M1 Collimation data (generated and implemented by J.Hill)

  • Check at ~30, ~60, ~85 degree elevations
  • Clear M2 active optics
  • Preset TRACK mode, PA=0
  • Record initial wavefront correction, FWHM on 30s LUCIFER image

Preset to BS9187 EL~25 luci_20081007_0001 3.5 arcsec donuts, bad
Preset to BS9185 EL~49 luci_20081007_0002 ~0.75 arcsec FWHM, looks decent
Preset to BS9183 EL~63 luci_20081007_0003 ~1.25 arcsec FWHM, soft
Preset to Rndom EL~80 luci_20081007_0004 ~1.25 arcsec FWHM, soft

Take set of data for mount guiding filter analysis

  • filter=0.2 (default), take 10 minutes guiding data. 19:46-20:04MST (through gi471, wfs57)
  • filter=0.05, take 10 minutes guiding data.
  • reset filter=0.2 until analysis complete. 20:10-20:25 (through gi501-645)
  • compare rms of offsets vs. filter value.

See attached plot MtGuideFilt.pdf. The squares are the 0.2 data and the plusses are the 0.05 data. Running stats on the XY coordinates gives an rms of 0.273" for the 0.2 filter and 0.226" rms for the 0.05 filter. Probably not significant given the time and elevation differences. This may be because the servos on the mount already have some sophisticated filtering built in. Is there any other way to "tune" the guiding response?

Take astrometry data on LUCIFER for orientation

Note: Guider is running at 0.5s/exposure even though the star has only ~500 DN above the background. We should review the rescaling algorithm as there is no reason for this not to be running at 4.6 seconds.

  • Use LUCIastrom.cat:
    • Stone P @ PA=180 (RA~22:42) luci_20081007_0005 -0008
  • Take 30s total integration per pointing
  • Offset 30 arcsec and take another for sky

An astrometric solution to the Stone P image shows an achieved PA of 270.22 degrees.

Gather Pointing Model Data

  • In stable conditions (Br-gamma filter, ptime2 )
  • Collimate at ~50-60 degrees
  • Point to stars in TRACK mode, take minimum exposure

ACT0362 = 0009, WT10_407 = 0010, ACT0396 = 0011, WT10_347= 0012, ACT0283 = 0013
...Forgot to start ptlog! Start over...20081007.ptlog file UT04:10

Files: luci_20081007_NNNN
For ROTCEN:
ACT0198 0014 PA=0 * ACT0198 0015 PA=180
Rotator center = 1015.85 1035.12 (using only 3 stars near the middle of the field)

Pointing data
WT10_362 0016 * WT10_407 0017 * ACT0396 0018 * ACT0347 0019
ACT0283 0020 * WT10_181 0021 * WT10_255 0022 * WT10_070 0023
ACT0170 0024 * WT10_276 0025 * WT10_227 0026 * ACT0327 0027
ACT0340 0028 * WT10_280 0029 * WT10_244 0030 * WT10_187 0031
ACT0308 0032 * ACT0102 0033 * WT10_132 0034 * WT10_234 0035
WT10_253 0036 * WT10_215 0037 * ACT0302 0038 * ACT0321 0039
WT10_391 0040 * ACT0406 0041 * WT10_410 0042 * WT10_323 0043
ACT0386 0044 * ACT0379 0045 * ACT0395 0046 * ACT0411 0047
WT10_378 0048 * WT10_358 0049 * ACT0362 0050 * ACT0360 0051

Lost tracking at UT05:42

New Pointing Model generated UT11:44: 27 stars, 4.54 arcsec rms
IA -314.0698 13.67512
IE -54.8126 2.64057
NPAE -7.3650 15.54302
AW +1.4949 1.01438
AN +19.5691 1.01697
TF +46.9452 3.67031
CA -1.7593 19.41978

Copied to the PCS configuration directory as LUCIFERSX.20081008.ptmod and the .conf file updated.

See both: 20081007.ptlog and 20081007b.ptlog. The latter started 05:22 after accidental stop of PCS. See also the attached tpoint output plot luci.20081008.tpfit.jpg.

Take astrometry data on LUCIFER for orientation

  • Use LUCIastrom.cat:
    • Stone A @ PA=45 (RA~00:43) luci_20081007_0052 - 0053
  • Take 30s total integration per pointing
  • Offset 30 arcsec and take another for sky

An astrometric solution to the Stone A image shows an achieved PA of 45.05 degrees.

Turn over to LUCIFER for calibrations...photometric zero points and sky emissivity.

Wed Oct 8 00:30:15.541 2008 StepFocus command failed for left LUCIFER for 0.000000000000000e+00
This happened because the step focus command was executed during the ~3 sec while the mirror was moving from the previous WFS collimation update. It is hard to defend against this. It seems to be exagerated tonight because Nancy's OB lasts just 2 WFS cycles before the next dither, so there is a beating problem.

Star is lost during offset problem

Wed Oct 8 00:36:10.278 2008 Offset command started for left LUCIFER from IIF
Wed Oct 8 00:36:40.259 2008 Offset command complete for left LUCIFER from IIF
While this command apparently succeeded, the was no star in the guider after the offset command was executed. The guider frame immediately before the offset command had a good star image.

It looks like the last guiding correction (from image 1300) arrived after the telescope had executed the offset so there was an apparent 20 arcsec error in the centroid position. Note that here dRa=0 dDec=0 means an offset back to the pointing origin - the actual offset was 20 arcsec in X.

Here is what PCS logged:
Oct  8 00:36:10 lbtmu102 LBT_PCS: PCS:TELESCOPE:OffsetTelescopeEquatorial executed
Oct  8 00:36:10 lbtmu102 LBT_PCS: Telescope. side: 0 dRA: 0 dDec: 0 dAngle: 0 MoveType: 0 newpos: 1
Oct  8 00:36:10 lbtmu102 LBT_PCS: newRA: 01:49:46.950000000 newDec: +48:37:53.300000000 newpos: 1 authIndex: 3
Oct  8 00:36:10 lbtmu102 LBT_PCS: Offset Parameters: 0 0 0
Oct  8 00:36:10 lbtmu102 LBT_PCS: PCS:TELESCOPE:OffsetTelescopeEquatorial execution time: 38 ms at 1223451370348
Oct  8 00:36:10 lbtmu102 LBT_PCS: PCS:GUIDER:ApplyGuideCorrection executed
Oct  8 00:36:10 lbtmu102 LBT_PCS: Centroid Xarcs: 216.210581461588561 Yarcs: 175.993131001790374 Xmm: 129.726348876953125 Ymm: 105.595878601074219
Oct  8 00:36:10 lbtmu102 LBT_PCS: PCS:GUIDER:ApplyGuideCorrection execution time: 37 ms at 1223451370720

Here is what GCS logged:
Oct  8 00:36:10 lbtmu107 LBT_left_GCS: PROFILING: sending guide correction to PCS...
Oct  8 00:36:10 lbtmu107 LBT_left_GCS: pcsClient.guider.applyGuideCorrection(129.726345,105.595875);
Oct  8 00:36:10 lbtmu107 LBT_left_GCS: GCSL:pauseGuiding executed
Oct  8 00:36:10 lbtmu107 LBT_left_GCS: PROFILING: sent guide correction to PCS.
Oct  8 00:36:10 lbtmu107 LBT_left_GCS: WFS: pausing loop
Oct  8 00:36:10 lbtmu107 LBT_left_GCS: pausing guide loop. timeout for loop to respond = 2322 ms. divided into 100 steps. wait per step = 23220 usecs
Oct  8 00:36:10 lbtmu107 LBT_left_GCS: WFS: aborting waiting for image as a pause request was received..
Oct  8 00:36:12 lbtmu107 LBT_left_GCS: PROFILING: delaying guide loop by 973020 usecs...
Oct  8 00:36:12 lbtmu107 LBT_left_GCS: PROFILING: delay done.
Oct  8 00:36:12 lbtmu107 LBT_left_GCS: guiding paused

The next error:
Oct  8 01:10:39 lbtmu107 LBT_left_GCS: GCSL:pauseGuiding executed
Oct  8 01:10:39 lbtmu107 LBT_left_GCS: WFS: pausing loop
Oct  8 01:10:39 lbtmu107 LBT_left_GCS: pausing guide loop. timeout for loop to respond = 2093 ms. divided into 100 steps. wait per step = 20930 usecs
Oct  8 01:10:39 lbtmu107 LBT_left_GCS: WFS: aborting waiting for image as a pause request was received..
Oct  8 01:10:40 lbtmu107 LBT_left_GCS: GCSL:getGuideImage executed
Oct  8 01:10:40 lbtmu107 LBT_left_GCS: effective Guide Rate: 0.251877   max. Guide Rate: 1.293842
Oct  8 01:10:40 lbtmu107 LBT_left_GCS: GCSL:getGuideImage execution time: 28 ms at 1223453440561
Oct  8 01:10:40 lbtmu107 LBT_left_GCS: GCSL:getCentroid executed
Oct  8 01:10:40 lbtmu107 LBT_left_GCS: GCSL:getCentroid execution time: 20 ms at 1223453440601
Oct  8 01:10:40 lbtmu107 LBT_left_GCS: GCSL:getCentroid executed
Oct  8 01:10:40 lbtmu107 LBT_left_GCS: GCSL:getCentroid execution time: 21 ms at 1223453440641
Oct  8 01:10:40 lbtmu107 LBT_left_GCS: GCSL:getGuideCamPixelScale executed
Oct  8 01:10:40 lbtmu107 LBT_left_GCS: GCSL:getGuideCamPixelScale execution time: 7 ms at 1223453440663
Oct  8 01:10:40 lbtmu107 LBT_left_GCS: GCSL:getCentroid executed
Oct  8 01:10:40 lbtmu107 LBT_left_GCS: GCSL:getCentroid execution time: 24 ms at 1223453440713
Oct  8 01:10:41 lbtmu107 LBT_left_GCS: warning for pauseLoop: after waiting for 2093 ms the guide loop is still active!
Oct  8 01:10:41 lbtmu107 LBT_left_GCS: couldn't pause guide loop.
Oct  8 01:10:41 lbtmu107 LBT_left_GCS: GCSL:pauseGuiding execution time: 2211 ms at 1223453441835
Oct  8 01:10:42 lbtmu107 LBT_left_GCS: PROFILING: delaying guide loop by 170331 usecs...
Oct  8 01:10:42 lbtmu107 LBT_left_GCS: PROFILING: delay done.
Oct  8 01:10:46 lbtmu107 LBT_left_GCS: GCSL:stopGuiding executed
Oct  8 01:10:46 lbtmu107 LBT_left_GCS: GCS Subsystem stops WF sensing
Oct  8 01:10:46 lbtmu107 LBT_left_GCS: WFS thread stopped.
Oct  8 01:10:46 lbtmu107 LBT_left_GCS: GCS Subsystem stops guiding
Oct  8 01:10:46 lbtmu107 LBT_left_GCS: guide thread stopped.
Oct  8 01:10:46 lbtmu107 LBT_left_GCS: GCSL:stopGuiding execution time: 86 ms at 1223453446312

This happened a second time, so we restarted the GCS at 01:29 MST.

02:15 Chris puts a new IIF on the mountain which waits until the pause guiding is really paused before sending any offset command to PCS. Note that this problem was fixed before an Issuetrak was issued, so it doesn't have a number.



Recenter AGw on optical/rotator axis

LUCIFER morning twilight flats?

If there is time during the night:

LUCIFER taking sky emissivity data
    • TRACK mode, blank fields, measure count rate vs. filter
  • Gather low-EL AGW dataset for binodal astig (need appropriate target field).
  • Re-center WFS on rotator center
  • Usable guide star magnitude (record Rmag, FWHM, peak counts)
  • Others?

-- DavidThompson - 07 Oct 2008
I Attachment Action Size Date Who Comment
M2sphere.pdfpdf M2sphere.pdf manage 20 K 09 Oct 2008 - 10:09 DavidThompson  
MtGuideFilt.pdfpdf MtGuideFilt.pdf manage 21 K 09 Oct 2008 - 07:56 DavidThompson Plot of mount guide filter data (0.2 and 0.05)
luci.20081008.tpfit.jpgjpg luci.20081008.tpfit.jpg manage 36 K 09 Oct 2008 - 23:34 DavidThompson  
Topic revision: r9 - 09 Oct 2008, DavidThompson
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