Commissioning Notes from 12th-13th June 2008 MST

Observers: D. Miller, A. Rakich (in Tucson).
OSA: David G.-H., J. M. Hill
Software: T. Leibold, S. Hooper

Summary

GCS much improved since last night, on and off-axis guiding acquisition and guiding working pretty reliably. Wild oscillations while guiding seem to have gone, although we saw a few mild oscillations. Tested GCS WFS and came up with a list of things to do ASAP. Verified beyond a doubt that the tertiary mirror is the main source of pupil vignetting (which is expected). Also we are running off the lenslet array 2 whole subapertures when we get to the edge of the AGW field (this needs an adjustment of the camera inside AGw). Spent the latter part of the night taking data for a new pointing and collimation model . Concluded taking data to refine Chris's coefficient for z4. Seeing on guider was 0.4 to 0.6 arcsec for most of the night, degrading to 0.7-0.8 arcsec at the end.

Night time Activities

(Times are in MST)

8:30 gone to BS9153, used following pointing offsets: CA=-88, IE -47

8:39 add +7000 z4 manually

8:43 got onto guiding straight away, star bullseyed in the centre of the guide box. Collimating using 11X11 array. WFSC 2-7

8:56 going off-axis to #12 at AGw Y coordinate 446mm, 4.625 arc minutes offaxis. Torsten's changes to GCS seem to work, acquiring guiding off-axis, no oscillations, star bullseyed on guide box, all very good. No pupil vignetting from tertiary (wfsc9) but obvious loss of a row of sub-apps at top of WFS image.

9:07 Going to star #2, a little over 90 degrees around from #12, so now we expect to see tertiary vignetting. Find star is off-chip. Go back to #12 to offset star up and to the right, should bring 2 on-chip.

9:23 reset as follows: IE = -55; CA= -77; no star at #2, doing spiral search... new offsets 30"RA, 0" Dec. Doug comments that this is the same magnitude as the initial offset to the pointing model from the start of the night. Doug predicts IE=-38, CA=-108 will match this new star. End up with zero offset with IE = -73, CA = -108

9:37 Killing GCS and restarting.

9:46 Star #2 showing significant pupil vignetting (wfsc 10) presumably from tertiary also now we are at 427 on AGw Y axis = 5.15' offaxis and we are now losing 2 rows of subapps. This is not good. Now going to star #16.

9:55 went to star 16 but couldn't find it, reverted to IE=-55, CA = -77 and found the star but too close to the edge for offset to hotspot, putting it on... end up at IE = -45 CA =- 81. Sending preset. Star # 16 is at 5.29' radial off-axis and pretty much diametrically opposite star#2. Andrew sees clear outline of octagonal tertiary corner (wfsc16).

10:15 test running GCS WFS. Switch sendZernikesToPSF (0,1 for on-off). triggerWFS command. Produced underexposed image, redoing with 15 seconds.

10:37 first successful GCS WFS image on sky! wfscimage00002-5 in /temp. Clear outline of Tertiary there. Now going on-axis and testing sending Zernikes to PSF. Not working sending a new build of GCS with increased timeouts waiting for images.

11:00 move to star BS9177 trying GCS WFS collimation on aberrated on-axis star. GCS says that it sent Zernikes to PSF, but Zernikes not received. Also we need to turn off values for Z2 and Z3.

11:20 identified several bugs with GCS WFS as follows: 1) not sending to PSF. 2) need to implement pupil shift. 3) problem with de-rotation. 4) Zernike's not matching Doug's code. 5) field offsets for aberration. 6) tip/tilt removal algorithm 7) sent Zernike coefficients

11:42 have decided to proceed wtih an upgrade to the pointing and collimation models as we are having too much trouble finding stars offaxis and the collimation model usually starts us off with pretty aberrated stars at the moment.

Pointing and Collimation Model

11:45 Reset telescope elevation encoders. This fails on first 6 attempts.

12:20 June132008PointingLog

Preset Telescope with Guiding using Persson stars from the Marco list.

Collimate using the Doug IDL code.

Record last WFS image number for its header information.

takepic 1 with NOTHING on IRTC for collecting additional header information.

Write down Total Collimation values from PSF.

Preset to next star, and so on............

Jun 14 00:51:52 lbtmu107 LBT_left_GCS: fatal error: did not receive full CCD readout from guide camera within timeout period of 3659 ms.

12:57 Polycom network problems which are cured after 10 minutes by power cycling both units.

Jun 14 01:07:14 lbtmu107 LBT_left_GCS: fatal error: did not receive full CCD readout from guide camera within timeout period of 3659 ms. (recovered by retrying the acquisition)

Jun 14 01:09:35 lbtmu107 LBT_left_GCS: fatal error: did not receive full CCD readout from guide camera within timeout period of 3659 ms.

Jun 14 01:26:44 lbtmu107 LBT_left_GCS: AGW::setxy(-0.4, 612.3) returned 201 Jun 14 01:26:44 lbtmu107 LBT_left_GCS: error: setProbePosition: couldn't move probe to position (SFP) (x,y): 0.375574, 0.186937 mm.

Remember to roll out more negative X next time so we can go to lower elevation. We are hitting the +X limit at +40 deg EL.

Jun 14 02:13:46 lbtmu107 LBT_left_GCS: fatal error: did not receive full CCD readout from guide camera within timeout period of 3659 ms.

Jun 14 02:24:04 lbtmu107 LBT_left_GCS: fatal error: did not receive full CCD readout from guide camera within timeout period of 3659 ms.

2:35 Have observed a constant astigmatism residual in the guide camera images when the WFS reports <50 nm aberration. It turns out that we are not currently using the null file taken using the AGw test source, so need to test that soon.

3:11 continuing taking images for collimation and pointing model, have run out of BS stars, moved onto much brighter WT stars. Now taking 2s WFSC images, so active optics is giving returns at about seeing limit, so still useful for collimation and pointing model.

IRTC# in the list below indicates IRTC filename like irtc.20080614.111806.fits (presently in /Repository)

WFS# is the last collimated WFS image with filename like wfsc000023_dd.fits (in sub-directory)

STAR	UTIME	X	Y	Z 	RX	RY	EL	TEMP	WFS#	IRTC#
BS9166 07:38	1.066	-0.700	1.222	34.35	-30.03	73.0	13.47	23	074007
BS9162 07:49	1.546	-1.101	1.611	33.89	-33.13	62.7	13.49	28	074901
BS9169 07:56	1.527	-1.100	1.479	32.85	-33.62	66.1	13.50	31	075634
BS9177 08:03	1.287	-0.796	1.219	33.39	-32.47	73.0	13.51	34	080338
BS9158 08:18 	2.110	-1.352	2.143	33.67	-35.86	46.9	13.54	38	081833
BS9164 08:24	2.067	-1.331	2.036	33.76	-35.98	49.6	13.53	41	082443
BS9170 08:34	1.987	-1.297	1.932	33.94	-35.68	52.1	13.55	44	083420
BS9160 08: x-limit
BS9152 08: x-limit
BS9177 08:59	1.330	-0.768	1.192	33.96	-32.83	72.5	13.54	55	090127
BS9183 09:09	1.841	-1.137	1.775	35.01	-35.04	56.5	13.54	58	091008
BS9178 09:19	2.010	-1.086	1.916	36.14	-35.89	52.2	13.52	63	092003
BS9162 09:28	2.291	-1.246	2.110	34.78	-37.64	46.2	13.52	66	092842
BS9166 09:35	2.149	-1.224	2.030	34.95	-36.64	48.6	13.52	69	093528
BS9169 09:41	1.976	-1.116	1.835	35.54	-36.05	54.5	13.52	72	094137
BS9177 09:47	1.375	-0.805	1.363	35.43	-32.34	67.8	13.51	75	094758
WT10_287 too bright at 1 millisec
WT10_319 10:08	1.092	+0.175	0.618	35.48	-33.06	87.4	13.47	83	100850 1ms 2sec
WT10_319 10:15	1.086	+0.102	0.677	35.57	-32.75	86.7	13.46	92	101513 1ms 2sec
WT10_304 too bright at 1 millisec
WT10_272 10:28  1.087	-0.508	1.097	35.27	-30.67	75.3	13.43	102	102905 1ms 2sec
BS9183 10:37	1.434	-0.850	1.533	36.08	-32.12	64.0	13.41	106	103656
BS9183 11:16	1.590	-0.917	1.538	35.62	-33.41	62.6	13.31	150	111806

Z4 coefficient tuning

3:30 Going to BS9183 to take Z4 as a function of Z11 changes data, collimating wfsc 103-106; taking set of five data after collimation wfsc107-111

3:38 z11 +250 wfsc 112-116

3:42 z11 back to zero recollimate

3:49 taking set of 5 with +500 z11 wfsc120-124

3:53 recollimate

3:55 set of 5 at Z11 +1000nm wfsc 127-131

3:59 recollimate

4:01 z11 -500 5 images wfsc 133-137

4:04 recollimate

4:11 z11 -1000nm 5 sets of images wfsc145-149

The impending dawn limits any more pointing stars.

4:30 close, stop pointing log.

-- JohnHill - 14 Jun 2008
Topic revision: r5 - 14 Jun 2008, JohnHill
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