23 June 2013 LBC IQ Technical Observing Night 2

OSA: Steve Allanson
Telescope Manager: Jeff Urban
Observers: Steven Villanueva, Olga Kuhn


We first obtained extra and intra-focal pupil images with the LBCs and with a board over the mirror, to remove doubt as to where the "skirt", or other features we may see on the blue pupils are coming from.

Then, at ~04 UT, we started to obtain data for a collimation model, moving down from 85 to 15 deg elevation, then up to 85, back down to 15 and finally up again; 40 deg was the last point because it got too light. We stayed along the meridian and in the N. At low elevations, z4, z11 and z22 corrections were high and FPIA took 6-7 iterations before converging, giving large negative z4 and positive z11 and z22 on the downward tracks and large positive z4 and negative z11 and z22 on the upward tracks. As I write the end-of-night summary, I am wondering whether we should have cleared active optics at each slew. Instead we let dofpia do, or try to do, the work, but clearing active optics may have created a 'cleaner' data set for a collimation model. Also we might have avoided the meridian where parallactic angle changes most rapidly. This dataset seems pretty interesting though, and, except for going to the extremely low elevations, approximates how the LBC has been used for science nights.

We ran superfoc sequences at 3 elevations (75 deg, 55 deg and 25 deg) during the first track going down and then up. I did not look at the red sequences yet, but the blue again show some scatter in on-axis best-focus, from -0.03mm, to ~0mm and two with 0.02mm and, at very low elevations, it was up to 0.1mm, not too surprising given the large z4,z11,z22 cumulative corrections here.

The plan for Night 3, unless there are indications otherwise, is to obtain more focus sequences, to measure filter focus offsets, and some 4 chip extra- and intra-focal pupil images at rV and at other pairs of filters, at one or two fields for which elevation will not change too quickly. We could also repeat one down/up sequence for a collimation model with the one or both points mentioned above: staying away from exactly the meridian and clearing active optics offsets after each slew.


03:00 Were open at 02:25 and mirror ventilation has been running. Glass-to-ambient temperatures about 0.5 deg apart. Earlier we clamped a longer board onto the edge of the SX M1 cell, again close to the MV hoses and just over 180 deg from center-bent Gregorian port (i.e. closer to swing arm base). While doing this, we noticed that there was a hole in one of the MV hoses and air flowing out of it. I also noticed air flow from the edge around the mirror. But along DX there was also airflow from the outer edge of the mirror, at some places this is suppressed by the sfigotto but at other places where the sfigotto is not touching the primary, the airflow is less.

before 03:37 Focus/collimate on field at 78 deg elevation. We see a notch in the blue pupils, about where we expect the board to be. See attached image, lbcpupilsorientation.jpg.

03:40 RB_rV100exin4 OB run to take 100-pix extra/intra focal pupil images.
lbcb.20130623.033725.fits[2] FOCUS -1.320
lbcb.20130623.033833.fits[2] FOCUS 1.280
Run also RB_rVexin4.
  • Note that these extra and intra focal pupils are centered on -0.02mm as best focus. It looks like that is not the correct setting, and best-focus 0.0 would be better.

03:58 start collecting data for collimation model
  • Turned on pointing logging. Will create a file in /home/telescope/PointingLogs/. (We don't intend to collect actual data for a pointing model as we'll not slew in azimuth very much, though).
  • elev 85 deg.
    1. dofpia on copoint star
    2. run copoint ob
    3. lbcrangebal on resulting image pair
    4. run copoint ob again: lbcb.20130623.040804.fits and lbcr.20130623.040759.fits
  • elev 75 deg.
    • same sequence of steps 1-4.
      • blue images look round despite pupil "skirt", although definite elongation at bottom edge. See b 041727
      • 2nd copoint: lbcb.20130623.042234.fits and lbcr.20130623.042229.fits
    • run superfoc7 rV at PA=0 (seeing <~1"): -0.018 mm with fwhm 2.75 on axis.
lbcb.20130623.042431.fits[2] stars +74:55:22.21 RB_rV_superfoc7 -0.200
lbcb.20130623.042521.fits[2] stars +74:54:50.85 RB_rV_superfoc7 -0.140
lbcb.20130623.042610.fits[2] stars +74:53:59.63 RB_rV_superfoc7 -0.080
lbcb.20130623.042659.fits[2] stars +74:53:02.91 RB_rV_superfoc7 -0.020
lbcb.20130623.042748.fits[2] stars +74:52:00.37 RB_rV_superfoc7 0.040
lbcb.20130623.042837.fits[2] stars +74:50:51.99 RB_rV_superfoc7 0.100
lbcb.20130623.042927.fits[2] stars +74:49:37.01 RB_rV_superfoc7 0.160
    • run superfoc7 rV at PA=180 best-focus = -0.026 with FWHM 3.08.
lbcb.20130623.043130.fits[2] stars +74:47:01.01 RB_rV_superfoc7_pa -0.200
lbcb.20130623.043219.fits[2] stars +74:44:36.22 RB_rV_superfoc7_pa -0.140
lbcb.20130623.043308.fits[2] stars +74:42:57.80 RB_rV_superfoc7_pa -0.080
lbcb.20130623.043357.fits[2] stars +74:41:15.69 RB_rV_superfoc7_pa -0.020
lbcb.20130623.043446.fits[2] stars +74:39:23.52 RB_rV_superfoc7_pa 0.040
lbcb.20130623.043535.fits[2] stars +74:37:28.31 RB_rV_superfoc7_pa 0.100
lbcb.20130623.043625.fits[2] stars +74:35:25.70 RB_rV_superfoc7_pa 0.160
  • elev 65 deg.
    • second pair of copoint images after lbcrangebal: lbcb.20130623.044841.fits and lbcr.20130623.044836.fits
  • elev 60 deg.
    • second pair of copoint images after lbcrangebal: lbcb.20130623.045802.fits and lbcr.20130623.045758.fits
  • elev 55 deg.
    • first blue copoint image elongated (b 050447).
    • second pair: lbcb.20130623.050832.fits and lbcr.20130623.050828.fits
    • superfoc7 at PA=0 best-foc on-axis 0.009 with FWHM 3.82
lbcb.20130623.050939.fits[2] RB_rV_superfoc7 +55:14:01.45 -0.200
lbcb.20130623.051029.fits[2] RB_rV_superfoc7 +55:13:51.23 -0.140
lbcb.20130623.051118.fits[2] RB_rV_superfoc7 +55:13:35.90 -0.080
lbcb.20130623.051208.fits[2] RB_rV_superfoc7 +55:13:17.69 -0.020
lbcb.20130623.051255.fits[2] RB_rV_superfoc7 +55:12:59.00 0.040
lbcb.20130623.051344.fits[2] RB_rV_superfoc7 +55:12:38.99 0.100
lbcb.20130623.051434.fits[2] RB_rV_superfoc7 +55:12:16.49 0.160
    • superfoc7 at PA=180 best-foc on axis 0.0058 with FWHM 3.83
lbcb.20130623.051634.fits[2] RB_rV_superfoc7_pa +55:11:31.58 -0.200
lbcb.20130623.051724.fits[2] RB_rV_superfoc7_pa +55:10:50.08 -0.140
lbcb.20130623.051813.fits[2] RB_rV_superfoc7_pa +55:10:19.63 -0.080
lbcb.20130623.051902.fits[2] RB_rV_superfoc7_pa +55:09:50.86 -0.020
lbcb.20130623.051951.fits[2] RB_rV_superfoc7_pa +55:09:18.40 0.040
lbcb.20130623.052040.fits[2] RB_rV_superfoc7_pa +55:08:46.13 0.100
lbcb.20130623.052130.fits[2] RB_rV_superfoc7_pa +55:08:12.28 0.160
  • elev 50 deg.
    • second pair after lbcrangebal: lbcb.20130623.053136.fits and lbcr.20130623.053132.fits
  • elev 45 deg.
    • first blue image is elongated on-axis (see 053917).
      • dofpia had converged in one iteration. Seeing worse ~ 1.2"
    • second pair after lbcrangebal: lbcb.20130623.054129.fits and lbcr.20130623.054125.fits
  • elev 35 deg.
    • first pair - both blue and red IQ is not good. Blue FWHM is smaller than Red.
    • second pair after lbcrangebal: lbcb.20130623.055600.fits and lbcr.20130623.055557.fits
      • on second pair red iq is slightly better than blue
  • elev 25 deg.
    • second pair lbcb.20130623.061059.fits and lbcr.20130623.061055.fits
    • superfoc7 at PA=0 best-foc 0.034 FWHM 4.47
lbcb.20130623.061240.fits[2] RB_rV_superfoc7 +25:46:55.97 -0.200
lbcb.20130623.061329.fits[2] RB_rV_superfoc7 +25:46:58.48 -0.140
lbcb.20130623.061418.fits[2] RB_rV_superfoc7 +25:47:02.52 -0.080
lbcb.20130623.061507.fits[2] RB_rV_superfoc7 +25:47:06.75 -0.020
lbcb.20130623.061557.fits[2] RB_rV_superfoc7 +25:47:11.51 0.040
lbcb.20130623.061646.fits[2] RB_rV_superfoc7 +25:47:16.44 0.100
lbcb.20130623.061735.fits[2] RB_rV_superfoc7 +25:47:21.69 0.160
    • superfoc7 at PA=180 best-foc 0.068 at FWHM 5.56
lbcb.20130623.061936.fits[2] RB_rV_superfoc7_pa +25:47:32.38 -0.200
lbcb.20130623.062026.fits[2] RB_rV_superfoc7_pa +25:47:42.16 -0.140
lbcb.20130623.062115.fits[2] RB_rV_superfoc7_pa +25:47:48.73 -0.080
lbcb.20130623.062204.fits[2] RB_rV_superfoc7_pa +25:47:55.64 -0.020
lbcb.20130623.062254.fits[2] RB_rV_superfoc7_pa +25:48:02.96 0.040
lbcb.20130623.062342.fits[2] RB_rV_superfoc7_pa +25:48:10.42 0.100
lbcb.20130623.062431.fits[2] RB_rV_superfoc7_pa +25:48:17.88 0.160
  • elev 15 deg
    • FPIA is running away again, as we saw yesterday, giving negative z4, positive z11 and positive z22. Stopping with "S" and going to elev=20.
  • elev 20 deg.
    • dofpia converged (unlike at elev 15 deg).
    • in first pair of copoint images, red is noticeably elongated (see 064302)
    • second pair after lbcrangebal: lbcb.20130623.064526.fits and lbcr.20130623.064520.fits
  • elev 15 deg.
    • now red pupils have a fuzzy edge (see 064928 for an example).
    • second pair after lbcrangebal: lbcb.20130623.065839.fits and lbcr.20130623.065834.fits
    • we had intended to continue to go up, to elev 25 deg, expecting that 20 deg was as low as we could go, since we saw both tonight and last night that there were problems with convergence at 15 deg elevation (18 deg last night). But surprisingly, there was no runaway z4, z11 or z22 and dofpia converged in 3 iterations.
  • elev 25 deg
    • converged in 3 iterations. Blue and also Red images appear elongated.
    • lbcrangebal - Steven noted that dIE was 10", so far tonight the pointing offsets have been 1-3".
    • second pair lbcb.20130623.071300.fits and lbcr.20130623.071256.fits
    • superfoc7 PA=0 best-foc 0.137 with FWHM 5.82 (for r, best-foc is also larger than nominal, 0.094, vs nominal value of 0.036).
lbcb.20130623.071537.fits[2] RB_rV_superfoc7 +24:57:28.98 -0.200
lbcb.20130623.071626.fits[2] RB_rV_superfoc7 +24:57:32.18 -0.140
lbcb.20130623.071715.fits[2] RB_rV_superfoc7 +24:57:37.38 -0.080
lbcb.20130623.071804.fits[2] RB_rV_superfoc7 +24:57:42.91 -0.020
lbcb.20130623.071853.fits[2] RB_rV_superfoc7 +24:57:48.73 0.040
lbcb.20130623.071943.fits[2] RB_rV_superfoc7 +24:57:55.22 0.100
lbcb.20130623.072031.fits[2] RB_rV_superfoc7 +24:58:01.68 0.160
    • superfoc7 PA=180 best-foc 0.147 with FWHM 5.84
lbcb.20130623.072229.fits[2] RB_rV_superfoc7_pa +24:58:14.27 -0.200
lbcb.20130623.072318.fits[2] RB_rV_superfoc7_pa +24:58:26.25 -0.140
lbcb.20130623.072408.fits[2] RB_rV_superfoc7_pa +24:58:34.27 -0.080
lbcb.20130623.072457.fits[2] RB_rV_superfoc7_pa +24:58:42.76 -0.020
lbcb.20130623.072546.fits[2] RB_rV_superfoc7_pa +24:58:51.59 0.040
lbcb.20130623.072635.fits[2] RB_rV_superfoc7_pa +24:59:00.23 0.100
lbcb.20130623.072724.fits[2] RB_rV_superfoc7_pa +24:59:09.54 0.160
  • elev 35 deg.
    • note that the first z4 sent by dofpia is a large positive value. On the way down, the first z4 sent by dofpia at low elevation (elev 25 deg) was a large negative value.
    • lbcrangebal sent dIE, dCA ~ 6, -5"
    • second pair (after lbcrangebal): lbcb.20130623.073811.fits and lbcr.20130623.073807.fits
  • elev 45 deg.
    • first copoint pair: red images noticeably elongated. blue also somewhat elongated (see lbcb.20130623.074519.fits and lbcr.20130623.074515.fits)
    • second copoint pair: lbcb.20130623.074733.fits and lbcr.20130623.074729.fits
  • elev 50 deg.
    • both images of pair appear elongated (b 075343 and r 075341)
    • second copoint pair: lbcb.20130623.075629.fits and lbcr.20130623.075626.fits
  • elev 55 deg.
    • second copoint pair: lbcb.20130623.080455.fits and lbcr.20130623.080451.fits
      • blue fwhm gradient, at bottom horiz elong images.
    • superfoc7 PA=0 best-foc 0.014mm with FWHM 3.47
lbcb.20130623.080607.fits[2] RB_rV_superfoc7 +55:09:12.50 -0.200
lbcb.20130623.080656.fits[2] RB_rV_superfoc7 +55:09:03.72 -0.140
lbcb.20130623.080746.fits[2] RB_rV_superfoc7 +55:08:49.04 -0.080
lbcb.20130623.080835.fits[2] RB_rV_superfoc7 +55:08:32.43 -0.020
lbcb.20130623.080924.fits[2] RB_rV_superfoc7 +55:08:15.47 0.040
lbcb.20130623.081013.fits[2] RB_rV_superfoc7 +55:07:55.97 0.100
lbcb.20130623.081102.fits[2] RB_rV_superfoc7 +55:07:34.87 0.160
    • superfoc7 PA=180 best-foc 0.002 with FWHM 2.83
lbcb.20130623.081301.fits[2] RB_rV_superfoc7_pa +55:06:53.81 -0.200
lbcb.20130623.081350.fits[2] RB_rV_superfoc7_pa +55:06:12.82 -0.140
lbcb.20130623.081440.fits[2] RB_rV_superfoc7_pa +55:05:46.30 -0.080
lbcb.20130623.081529.fits[2] RB_rV_superfoc7_pa +55:05:17.58 -0.020
lbcb.20130623.081618.fits[2] RB_rV_superfoc7_pa +55:04:48.09 0.040
lbcb.20130623.081707.fits[2] RB_rV_superfoc7_pa +55:04:15.83 0.100
lbcb.20130623.081756.fits[2] RB_rV_superfoc7_pa +55:03:42.70 0.160
  • elev 60 deg.
    • pointing offsets required by lbcrangebal are small now.
    • second copoint pair is lbcb.20130623.082750.fits and lbcr.20130623.082746.fits
  • elev 65 deg.
    • note elongation again... both blue and red.
    • second copoint pair is lbcb.20130623.083625.fits and lbcr.20130623.083621.fits
  • elev 75 deg.
    • second copoint pair is lbcb.20130623.084512.fits and lbcr.20130623.084508.fits
    • superfoc7 PA=0 best-focus 0.018 with FWHM 2.74
lbcb.20130623.084620.fits[2] RB_rV_superfoc7 +75:05:19.04 -0.200
lbcb.20130623.084710.fits[2] RB_rV_superfoc7 +75:04:53.41 -0.140
lbcb.20130623.084758.fits[2] RB_rV_superfoc7 +75:04:03.54 -0.080
lbcb.20130623.084848.fits[2] RB_rV_superfoc7 +75:03:13.75 -0.020
lbcb.20130623.084936.fits[2] RB_rV_superfoc7 +75:02:15.08 0.040
lbcb.20130623.085023.fits[2] RB_rV_superfoc7 +75:01:13.43 0.100
lbcb.20130623.085112.fits[2] RB_rV_superfoc7 +75:00:02.19 0.160
    • superfoc7 PA=180 best-focus 0.02 FWHM 2.62
lbcb.20130623.085312.fits[2] RB_rV_superfoc7_pa +74:57:40.23 -0.200
lbcb.20130623.085401.fits[2] RB_rV_superfoc7_pa +74:55:21.76 -0.140
lbcb.20130623.085450.fits[2] RB_rV_superfoc7_pa +74:53:46.83 -0.080
lbcb.20130623.085539.fits[2] RB_rV_superfoc7_pa +74:52:06.29 -0.020
lbcb.20130623.085628.fits[2] RB_rV_superfoc7_pa +74:50:20.42 0.040
lbcb.20130623.085715.fits[2] RB_rV_superfoc7_pa +74:48:33.47 0.100
lbcb.20130623.085805.fits[2] RB_rV_superfoc7_pa +74:46:37.06 0.160
  • elev 85 deg
    • Kepler field...crowded...FPIA complains about too many iterations, unable to compute sky (from mmm.pro routine). Did not complain a second time on red, but did on blue.
    • Images look rounder - though red still has some lower-left to upper right elongation (090854).
    • second copoint pair is lbcb.20130623.091203.fits and lbcr.20130623.091159.fits
      • second blue image seems to have worse IQ on-axis than first.
  • elev 75 deg
    • second copoint pair is lbcb.20130623.092124.fits and lbcr.20130623.092120.fits
  • elev 65 deg
    • second copoint pair is lbcb.20130623.093144.fits and lbcr.20130623.093140.fits
    • difference in IQ after/before before lbcrangebal, as I have seen on some other sets. lbcrangebal should not introduce coma, but what about other aberrations? Note the images are just 1 sec.
  • elev 60 deg
    • second copoint pair is lbcb.20130623.094138.fits and lbcr.20130623.094135.fits
  • elev 55 deg
    • second copoint pair is lbcb.20130623.094903.fits and lbcr.20130623.094900.fits
  • elev 50 deg
    • second copoint pair is lbcb.20130623.095539.fits and lbcr.20130623.095535.fits
  • elev 45 deg.
    • second copoint pair is lbcb.20130623.100433.fits and lbcr.20130623.100429.fits
  • elev 35 deg.
    • second copoint pair is lbcb.20130623.101203.fits and lbcr.20130623.101157.fits
  • elev 25 deg.
    • FPIA first z4 offsets are large negative numbers (and those after it).
      • for these low elevations, rotator is at 0 deg and not 180 deg as it has been for higher elevations. That should not matter, but merits closer look at any dependence of FPIA convergence and rotator angle for tonight's down/up/down/up sequences. (but see below...)
      • took 6 iterations, but finally converged.
      • red ccd error: too many downloaded pixels (opened new IT 4713)
    • second copoint pair is lbcb.20130623.103504.fits and lbcr.20130623.103500.fits
  • elev 15 deg
    • again giving large negative z4 and positive z11, z22 corrections, and the rotator angle is the same as for elev=25, 0 deg. So it seems more like an offset from the collimation lookup table that is being input by FPIA.
    • the seeing threshold for spherical is too high... FPIA should not be sending spherical for this poor seeing.
    • 7 iterations but converged.
    • second copoint pair is lbcb.20130623.105312.fits and lbcr.20130623.105308.fits
  • elev 20 deg
    • large positive z4 and negative z11, z22 given on first iteration
    • FPIA converged on 3 iterations. But IQ is pretty poor.
    • second copoint pair is lbcb.20130623.110319.fits and lbcr.20130623.110315.fits
  • elev 30 deg
    • taking many iterations to remove the z11, z22 that had built up... 6 in all.
    • second copoint pair is lbcb.20130623.111959.fits and lbcr.20130623.111955.fits
  • elev 40 deg
    • getting light so switching to dofpia without the /x2 keyword. Converged in 2 iterations, still adding z4 and removing z11,z22.
    • second copoint pair is lbcb.20130623.112907.fits and lbcr.20130623.112903.fits.
  • at elev 47 deg, we cannot focus, sky is too bright.

11:35 Too bright to continue. Turning off pointing log.

Sunday afternoon

I extracted the mirror X,Y,Z,RX,RY positions from the headers of the second copoint pair of images (the pair of images obtained after running dofpia and running lbcrangebal on the first copoint pair). The positions are scaled to temperature, T301, = 0 deg C, using the temperature coefficients in the lookup table.

These data scaled to T301=0 C, are plotted against elevation in the attached plots sx_20130623.jpg and dx_20130623.jpg. The elevation tracks are color coded:
  • the blue track --- the first set of "down" data taken from elevation 85 to 15 deg.
  • the red track --- the first set of "up" data taken from elevation 15 to 85 deg.
  • the green track --- the second set of "down" data taken from elevation 85 to 15 deg.
  • the magneta track --- the second set of "up" data taken from elevation 15 to 40 deg (when it became too light to continue).
  • the solid black lines plot the collimation lookup table for T301=0 degrees.

There is noise at mid-elevations. And no tracks appear to repeat the first "down" track. The image quality was noticeably better during the first "down" track. Thereafter, we often saw elongated images on the copoint fields.

I don't know what happened at very low elevation between the blue and red tracks. Both sides were affected.

The temperature measured at the upper C-ring extension, T301, that is used in the collimation lookup table dropped from 12.5 to 9 C during the collection of these data. The plots sx_t301range_20130623.jpg and dx_t301range_20130623.jpg show the collimation lookup table plotted for this range of temperature: blue(9 C), black (the midpt between the two extremes --- 10.75 C) and red (12.5 C).

Attached plots sxraw_20130623.jpg and dxraw_20130623.jpg show the raw mirror positions, not corrected for temperature. The Z position is corrected for filter focus offset, but all data on each side were obtained with the same filter. The blue,black and red tracks show the collimation lookup table for T301=9, 10.75 and 12.5 deg C.

-- OlgaKuhn - 23 Jun 2013
I Attachment Action Size Date Who Comment
blue2013-06-23.LogLog blue2013-06-23.Log manage 21 K 23 Jun 2013 - 21:27 OlgaKuhn blue2013-06-23.Log (FPIA log)
dx_20130623.jpgjpg dx_20130623.jpg manage 153 K 23 Jun 2013 - 23:28 OlgaKuhn DX x,y,z,rx,ry plot for 20130623 collimation data
dx_t301range_20130623.jpgjpg dx_t301range_20130623.jpg manage 135 K 23 Jun 2013 - 22:59 OlgaKuhn DX model for T301=9(blue),10.75(black),12.5(red)
dxraw_20130623.jpgjpg dxraw_20130623.jpg manage 181 K 24 Jun 2013 - 00:49 OlgaKuhn DX raw X,Y,Z,RX,RY mirror positions
lbcpupilorientation.jpgjpg lbcpupilorientation.jpg manage 47 K 23 Jun 2013 - 03:46 OlgaKuhn board clamped to SX M1 cell near MV hoses.
red2013-06-23.LogLog red2013-06-23.Log manage 21 K 23 Jun 2013 - 21:27 OlgaKuhn red2013-06-23.Log
sx_20130623.jpgjpg sx_20130623.jpg manage 148 K 23 Jun 2013 - 23:28 OlgaKuhn Sx x,y,z,rx,ry plot for 20130623 collimation data
sx_t301range_20130623.jpgjpg sx_t301range_20130623.jpg manage 133 K 23 Jun 2013 - 22:58 OlgaKuhn SX model for T301=9(blue),10.75(black),12.5(red)
sxraw_20130623.jpgjpg sxraw_20130623.jpg manage 184 K 24 Jun 2013 - 00:48 OlgaKuhn SX raw X,Y,Z,RX,RY mirror positions
Topic revision: r5 - 24 Jun 2013, OlgaKuhn
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