Telescope and AGw Commissioning at LFBG with IRTC - 28-29 April 2009

Observers:: R .Green, J. Heidt, J. Hill (Tucson)
Telescope Operator: David Gonzalez Huerta
Software Support: P. Grenz (Tucson) Telescope Support: J. Little (mtn)

Summary

  • Good night overall. Seeing partly ~0.5 on guider in r', degraded later on.
  • No technical problems.
  • Offset tests with Daves dice5-script, 2, 5 and 8"
  • Lots of data for collimation model
  • Stone M field, 42 observations split over 2 PA's for verification transform (looks good)

Details

Open

19:00 MST Dome opened

19:23 Tdome=5.4 T(M1)=3.3 Tout=5.4 RH=18%, wind=16m/s (need to be careful).

19:30 pointto M5_0347 Tel="TRACK" PA=0 PAM-. Preset failed

Fibre to BG not linked

19:42 OK, Redo, pointto M5_0347 Tel="TRACK" PA=0 PAM-.

PTspiral, star found, OK, CA=-63, IE=-100

19:52 pointto BS9138 for initial collimation. WFS rms: 3900, 3500, 1290, 320, 280, OK (seeing ~0.9"@WFS)

Offset-tests (small offsets)

20:02 pointto BS9138 gs=5 (gs just guessed, Rmag=15.9, but worked)

20:06 dice5 offsets 5",5" (RADEC), IRTC.20090429_00001-9_cube
First cube not saved!

20:24 dice5 offsets 8",8" (RADEC), RTC.20090429_00010-19_cube Now all 10 cubes saved

20:41 dice5 offsets 2",2" (ALTAZ), RTC.20090429_00020-29_cube

20:58 dice5 offsets 5",5" (ALTAZ), RTC.20090429_00030-39_cube

21:15 dice5 offsets 8",8" (DETXY), RTC.20090429_00040-49_cube

Collimation model data

21:33 Preset to BS9138, GS=3, took long (secondary not ready for a while), Redo GS=6 (no GS found) Redo GS=9 (no GS found), seems to have lost pointing

21:47 pointto M5_1332 to check pointing, OK, CA=-73 IE=-110

21:53 Preset BS9138, OK
22:04 BS9138, GS=9 (R=12.7), irtc.20090429.050425, WFS-RMS=150
22:07 C11+30, GS=0 (R=5), no GS found
22:10 C11+29, GS=0 (R=5), no GS found
22:13 pointto M5_0425 to check pointing, OK, CA= -79, IE= -78
22:24, C11+30, irtc.20090429.052217.fits, WFS-RMS=100
22:26, C11+26, irtc.20090429.052547.fits, WFS-RMS=300
22:28, C11+20, no GS found
22:29, C11+24, EL=72, WFS-RMS=150, irtc.20090429.053557.fits
22:39, C11+20, again no GS found
22:43, C11+16, EL=65, WFS-RMS=370, irtc.20090429.054344.fits
22:45, C11+13, no GS found
22:45, C11+15, no GS found
22:47, pointto M5_0444 to check pointing, OK, CA= -65, IE= -86
22:51, C11+13, EL=61, WFS-RMS=300, irtc.20090429.055309.fits
22:54, C11+09, EL=58, WFS-RMS=300, irtc.20090429.055642.fits
22:57, C11+06, GS seems to be double no guiding
22:59, C11+03, EL=52, WFS-RMS=200, irtc.20090429.060111.fits
23:01, C11+00, EL=50, WFS-RMS=330, irtc.20090429.060340.fits
23:04, C11-03, EL=46, WFS-RMS=380, irtc.20090429.060553.fits
23:06, C11-06, EL=43, WFS-RMS=330, irtc.20090429.060752.fits
23:08, C11-09, EL=40, WFS-RMS=310, irtc.20090429.060951.fits
23:10, C11-12, EL=38, WFS-RMS=320, irtc.20090429.061146.fits
23:12, C11-15, EL=35, WFS-RMS=250, irtc.20090429.061341.fits
23:14, C11-18, EL=32, WFS-RMS=340, irtc.20090429.061545.fits
23:16, C11-21, EL=29, WFS-RMS=380, irtc.20090429.061742.fits
23:18, C11-24, EL=26, WFS-RMS=320, irtc.20090429.062111.fits
23:21, C11-27, EL=23, WFS-RMS=200, irtc.20090429.062410.fits
23:24, C11-30, no GS found
23:25, C11-33, no GS found
23:27, C11-24, no GS found
23:27, C11-21, no GS found
23:30, Pointing check, pointto M5_1301 Tel="ACQUIRE" gs=0 PA=0 PAM- , CA=-68, IE=-103
23:35, C11-30, no GS found :-(
23:36, C11-24, no GS found
23:37, C11-21, no GS found
23:40, Pointing check, pointto M5_1301 Tel="ACQUIRE" gs=0 PA=0 PAM- , CA=-68, IE=-138
23:41, C11-18, EL=29, WFS-RMS=390, irtc.20090429.064359.fits
23:44, C11-15, EL=31, WFS-RMS=280, irtc.20090429.064555.fits
23:46, C11-12, EL=33, WFS-RMS=280, irtc.20090429.064756.fits
23:46, C11-09, EL=35, WFS-RMS=230, irtc.20090429.064952.fits
23:50, C11-06, EL=37, WFS-RMS=180, irtc.20090429.065209.fits
23:52, C11-03, EL=39, WFS-RMS=140, irtc.20090429.065405.fits
23:55, C11+00, EL=42, WFS-RMS=230, irtc.20090429.065627.fits
23:56, C11+03, EL=43, WFS-RMS=250, irtc.20090429.065827.fits
23:58, C11+06, stupid observer, GS is double (see above), not done
00:02, C11+09, EL=43, WFS-RMS=220, irtc.20090429.070544.fits
00:06, C11+13, EL=47, WFS-RMS=370, irtc.20090429.070836.fits
00:06, C11+16, EL=43, WFS-RMS=400, irtc.20090429.071033.fits
00:09, C11+20, no GS found
00:06, C11+24, EL=51, WFS-RMS=240, irtc.20090429.071450.fits
00:19 C15+08, no GS found
00:22, Pointing check, pointto M5_0547 Tel="ACQUIRE" gs=0 PA=0 PAM- , CA=-63, IE=-152
00:25, C15+04, EL=58, WFS-RMS=210, irtc.20090429.072817.fits
00:28, C15+08, EL=62, WFS-RMS=210, irtc.20090429.073021.fits
00:30, C15+12, EL=66, WFS-RMS=320, irtc.20090429.073218.fits
00:33, C15+16, EL=70, WFS-RMS=280, irtc.20090429.073445.fits
00:35, C15+20, EL=74, WFS-RMS=100, irtc.20090429.074043.fits
00:41, C15+24, EL=78, WFS-RMS=140, irtc.20090429.074322.fits
00:43, C15+26, EL=80, WFS-RMS=90, irtc.20090429.074523.fits
00:45, C15+28, EL=81, WFS-RMS=200, irtc.20090429.074733.fits
00:45, C15+30, EL=83, WFS-RMS=260, irtc.20090429.075012.fits, GCS reports seeing of ~0.4-0.5"
00:50, C15+32, EL=84, WFS-RMS=170, irtc.20090429.075445.fits
00:54, C15+30, EL=84, WFS-RMS=220, irtc.20090429.075718.fits
00:58, C15+28, EL=83, WFS-RMS=280, irtc.20090429.080039.fits
01:01, C15+26, EL=82, WFS-RMS=210, irtc.20090429.080350.fits
01:04, C15+24, EL=80, WFS-RMS=160, irtc.20090429.080611.fits
01:08, C15+20, EL=77, WFS-RMS=200, irtc.20090429.080927.fits

Verification of AGW-transform

Done on Stone M Field at PA=190*
Stone M requires 100 x 0.25 second exposures

01:22 Pointing check, pointto M5_1459 Tel="ACQUIRE" gs=0 PA=0 PAM-

01:30 Started with verification AGW-transform

NN G* singleimg cube SFP_X SFP_Y AGW_X AGW_Y

01 45 084021 0050 -2.004 78.277 3.599 534.316
02 54 084742 0051 52.113 94.557 -50.217 516.844
03 41 085255 0052 -1.629 177.793 5.378 434.831
04 30 085624 0053 -68.434 90.339 70.298 523.719
05 16 085957 0054 -124.859 102.865 127.014 512.434
06 08 090612 0055 -169.512 55.509 170.683 560.734
07 31 091055 0056 -76.128 19.022 76.479 595.170
08 55 091433 0057 44.747 41.596 -43.938 569.955
09 79 091909 0058 178.634 36.139 -177.962 572.457 (not useful)
10 67 092247 0059 99.582 36.410 -98.947 573.922
11 60 092629 0060 88.982 117.919 -86.523 492.685
12 62 093043 0061 71.478 3.254 -71.494 607.695
13 36 093356 0062 -54.399 35.082 55.018 578.649
Correct pointing: CA=-69 IE=-135
14 17 094045 0063 -136.060 22.485 136.456 593.029
15 11 094713 0064 -147.183 110.302 149.557 505.476
16 21 095056 0065 -110.441 77.993 112.014 536.987
17 34 095515 0066 -43.188 156.613 46.495 456.918 Dbl*
18 50 095907 0067 27.233 88.223 -25.352 523.733
19 59 100355 0068 73.723 45.874 -72.869 565.035
20 63 100817 0069 91.239 80.612 -89.674 529.915 (not useful)
21 74 101237 0070 151.188 80.316 -149.589 528.891 (not useful)
Corrected pointing: CA=-57 IE=-151
22 55 103647 0071 44.857 41.593 -44.021 569.958
23 27 104004 0072 -92.176 55.004 93.337 559.550
24 10 104403 0073 -169.779 34.938 170.424 581.324
Seeing is degrading: GCS-Gui reports 1.5", Wind now around 15 m/s
25 25 104812 0074 -88.932 88.952 490.776 525.551
26 34 105231 0075 -43.109 156.611 46.385 456.922 Dbl*
27 61 105744 0076 81.820 62.543 -80.605 548.192
28 70 110132 0077 130.534 66.055 -129.261 543.599
29 66 110543 0078 107.037 97.245 -105.064 512.946
30 49 110935 0079 29.094 101.098 -26.985 510.820
Now switiching to PA=240, to get good coverage of XY-plane
31 27 111506 0080 -17.095 105.926 19.307 507.009
32 41 111821 0081 135.273 115.362 -132.933 494.202
33 10 112148 0082 -82.348 152.470 85.578 461.920
34 11 112524 0083 -10.051 183.533 13.967 429.278
35 30 112913 0084 25.362 110.322 -23.055 501.681
36 34 113211 0085 92.282 133.640 -89.477 476.899
37 16 113522 0086 -1.354 161.590 4.735 451.020
38 02 113908 0087 -86.105 167.178 89.696 447.292 (not useful)
39 25 114151 0088 11.005 125.237 -8.360 487.088
40 08 114443 0089 -66.340 165.351 69.836 448.694
41 17 114821 0090 -70.162 118.535 72.613 495.576
42 21 115246 0091 -11.177 134.592 14.011 478.224

Close

04:55 Done, closing dome. Successfull night!

Analysis of Collimation Data

DJT extracted the collimation data from the image headers, and JMH analyzed the data with /home/lbcobs/Collimation/mkcoll_irtc.pro. The temperature was not as stable as you would hope for, since the glass temperature changed from 4.4 to 3.2 degC during the observations taken over a period of 3 hours (a stable night would be 2x less). The ambient temperature changed a similar amount. This turned out to be a quite interesting dataset since the temperature change allowed me to fit the temperature coefficients on a set of data that was otherwise clean and undisturbed. The slightly surprising results was that the temperature coefficients turned out to be 2 - 4 times larger than what we previously had estimated. These coefficients were optimized by a new and improved version of mkcoll_irtc.pro that steps through a range of coefficients and minimizes the rms to the fit (as opposed to the previous method of changing the coefficients by hand and squinting at the resulting plot). Warning: These coefficients may be wrong in true equilibrium conditions because they may include temperature gradient effects. We should also take care because these coefficients were measured over the relatively small temperature range of 1.2 degC - which makes a dangerous extrapolation over the operating range of 20 degC. If we can get some additional data at a different temperature before the telescope configuration changes, then we should be able to improve the coefficients signficantly.

When I reoptimize the IRTC data from 20080413 and 20080415, I find a Z-coefficient of 0.125 (half of what we see from last night), although those nights were not very stable either. The X- and Y-coefficients are harder to compare between then and now because we have changed how we are correcting coma in the meantime.

The attached plots show the data without temperature correction, the data with John's estimated coefficients from July 2008, and the optimized coefficients. For the first and third plot, the temperature coefficients and the rms around the fit is shown at the top of each plot panel. For example, the Z-coefficient of 0.23 mm per degC reduces the rms around the best fit from 0.077 mm rms to 0.016 mm rms.

The fourth plot is the same as the third plot (optimized coefficients), but with the yrange scaled to the full collimation range of the mirror. This illustrates the additional complication that this new collimation model will only be good in warm temperatures (assuming that these large temperature coefficients are correct), because we will hit the +Y-limit near 0 degC. The contours are plotted at 2 degC intervals.

-- Main.Jochen Heidt - 28 Apr 2009

  • Collimation Data with no temperature correction:
    irtc_20090429_none.gif

  • Collimation Data with John's July 2008 temperature corrections:
    irtc_20090429_jmh.gif

  • Collimation Data with self-optimized temperature coefficients:
    irtc_20090429_opt.gif

  • Collimation Data plotted with full collimation range and temperature contours:
    irtc_20090429_full.gif
I Attachment Action Size Date Who Comment
irtc_20090429_full.gifgif irtc_20090429_full.gif manage 25 K 30 Apr 2009 - 04:52 JohnHill Collimation Data plotted with full collimation range and temperature contours
irtc_20090429_jmh.gifgif irtc_20090429_jmh.gif manage 21 K 30 Apr 2009 - 01:35 JohnHill Collimation Data with John's July 2008 temperature corrections
irtc_20090429_none.gifgif irtc_20090429_none.gif manage 23 K 30 Apr 2009 - 01:34 JohnHill Collimation Data with no temperature correction
irtc_20090429_opt.gifgif irtc_20090429_opt.gif manage 22 K 30 Apr 2009 - 01:35 JohnHill Collimation Data with self-optimized temperature coefficients
Topic revision: r10 - 01 May 2009, JochenHeidt
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