UT 20130903 Technical Observing - LUCI1 and AGW1 Alignment at LFBG
Observer: JHill, DThompson (Tucson) DMiller (LBTO)
Telescope Operator: GBechetti (LBTO)
Software Support: DCox (Tucson)
AO Support: DMiller (LBTO)
Telescope Support: JUrban (LBTO)
Instrument Support: ESolheid (LBTO)
Dave took data for LUCI1 rotator center and zeropoint, and he is analyzing it overnight (see results below).
If weather and seeing are good, we will start Tuesday evening with LUCI1 transformation data.
We took field aberration data for AGW1@LFBG and confirmed that binodal aberration is small (at both LFBG and LDG see results below).
We did the AGw2 wake-up activities and did the initial alignment. The alignment had to be a multi-step bootstrap process
as M2 and M3 and AGW2 had all been dismounted.
Dave T. working on LUCI1 pupil alignment in twilight.
02:31 Open to mostly clear, but not photometric sky. T=14.5 degC, D=5 degC
LUCI1 Rotator Zeropoint and Rotator Center
Dave T. is doing this in a separate log........
03:45 Dave T. is done with his data collection
From the 6 images (3 fields, 2 exposures each) I get a mean residual rotation
(ignoring the usual significant digits rules) of 0.006 +/- 0.030 degrees,
so there is no need to change the LUCI1 LEFTZEROPOINT from the current value.
For the rotator center in the N3.75 camera, I find it is at 1017.17 1040.66 with
about 1-2 pixel rms. This is comparable to where it usually lands (offset about 2 arcsec
from the center of the detector). Don't believe the info in the headers…that is the rotcen
for the N1.8 camera. You can only have one rotcen in the LUCI1 software.
03:50 Doug M is testing his remote collection of LUCI images (getting ready for transformation data).
04:00 Seeing degrades from 0.8 to 2 arcsec, as we go through some clouds. That puts our plans for transformation data on hold.
Doug is having lots of problems trying to display the LUCI desktop on obs3 as LBTO - we think it is related to problems with the monitor configuration. See Issue 4783.
Practice Transformation Data on StoneO
Doug is collecting practice transformation data on the StoneO field. This is to make sure everything is working.
He is also making some improvements to the scripts such as trapping errors returned by the request for a LUCI image.
05:25 The seeing is as good as 0.7 arcsec on the guider, but variable seeing and intermittent clouds make it difficult to
get any consistent data.
Field Data on BS9177 using AGw1@LFBG
05:36 ACTIVE preset to BS9177 - seeing on guider is ~0.8 arcsec FWHM and variable - EL~57
The seeing varied from 0.6 to 1.1 arcsec during this data set.
06:29 Seeing puffs up above 2 arcsec at image 000314 then back to 1.1 arcsec for the next image.
06:41 Seeing blows up to 2 arcsec again
06:44 Lost the star to clouds.......image 000326 is no good.
Getting this message a couple times per hour on the GCSGUI:
"GCS is guiding but PCS is not accepting g"
see IT #4781 https://lbt.issuetrak.com/Issue_View.asp?IssueNbr=4781
06:55 Lost star due to clouds --- end of this data.
|| wfsc #
07:21 Field data Analysis DLM
- Could be some binodal but not really above the noise
- First part of data set was OK (0.8" seeing) but latter data poor (~1.0" seeing)
- No M2 position changes made
=> New Field Data Results
Measured bi-nodal astigmatism
From Astigmatism Measurement
Tip = -0.5", Delta IE = 0.5"
Tilt = 1.9", Delta CA = -1.9"
M2 Arcseconds and Millimeters
Delta RX = -5.", Delta Y = -0.025 mm
Delta RY = -19.", Delta X = -0.098 mm
- LFBG Field Astigmatism:
Switch to AGW2@RFBG for aliveness testing
06:58 to zenith to reconfigure swing arms
07:25 Found star M50036 at EL=51.7 at IE=-104 CA=-177
OK, everything is alive.
Realignment after M2 has been dismounted.
See the procedure in BGTechProcedures
Now we have to bootstrap the alignment when AGW2 and M3 and M2 have been dismounted.
ptreset to the default IE=-43 CA=-124
Adjusting M2 with coma free pointing -- hit limits on M1 and M2 ?? range-balancing?
Can't move M2 coma-free tilt in the negative direction that we need to go, because we hit the RY=899 limit.
Adjust the coma first X=-2.8 Y=-4.65 RX=485 RY=-291 so that buys a bit of RY headroom.
CA can't go any farther than -147 with Tilt limited to -30.
Tip needs -61 to get IE back to -43.
Doug points out that the M3 has been remounted also, so this initial procedure for adjusting collimation after M2 has been dismounted is not valid.
Next we work our way through a more bootstrap alignment procedure.....
Tip=-61 Tilt=-30 on M2 gives X=1.53 Y=3.11 RX=-599 RY=294
Doug and Geno trying active optics while John on Telecon with Italy. The active correction pushed M2 into the RY limit
09:04 Apply to M2 X=-2 RY=-200 Global offsets to get off the RY limit.
09:06 Apply John's coma correction from above to the M2 global offsets.
X=-4.8 Y=-4.65 RX=485 RY=491
We do not have any repointing applied to the secondary at this point, so we are using the corrected IE/CA values.
Updating the on-axis pupil position on the wfs
09:09 ACTIVE Preset
First we need to update the on-axis pupil position on the wfs, and we need to adjust the guiding hotspot.
09:22 New on-axis pupil center is 359.6, 258.4
---> Doug applied this to WFSCam_hotspot_x in LUCI_IRTC_R.cfg
(takes effect without restarting GCSR)
09:29 Clear Primary figure corrections, as we had some high order stuff stuck in there. That makes the wavefront look substantially
09:30 Doug is lowering the gain coefficients for Z9, Z10, Z11 to match those in use on the left side.
Then we ran into the M2 -Y limit (really the 10 mm radius)
Problems with Active Optics running away when hotspot is incorrect.
Adjusting the guiding hotspot
09:54 Adjusting guiding hotspot to get light into the wfs ---> 280, 230
Measuring Pupil Wobble from DX M3
10:13 Have nice 0.8 arcsec image now. Begin measuring pupil wobble.
Total Collimation M2 is X=0.052 Y=-6.875 Z=0.744 RX=391 RY=536 at EL=58.8
but Doug's pupil_collect routine had the side of the preset and offset hardwired to left.......he fixed that in a couple minutes
First measurement was at Tip=250 Tilt=-150
Absolute -208 +529 -25.831
Wispy clouds moving over.....
10:33 Move DX M3 Global Offset Tip from +200 to +500
in steps of 50 allowing the guider to follow
10:40 Move DX M3 Global Offset Tip from +500 to -300
arcsec. Tilt remains -150.
10:47 move DX M3 Global Offset Tilt from -150 to +50
arcsec. Tip remains -300.
10:50 move DX M3 Global Offset Tilt from +50 to +150
arcsec. Tip remains -300.
10:53 move DX M3 Global Offset Tilt from +150 to +250
arcsec. Tip remains -300.
10:56 Move DX M3 Global Offsets Tip from -300 to -200
arcsec. Tilt remains +250
Absolute coordinates: Tip=-608 Tilt=+930 RZ=-25.831
JMH: These were archived in DXTMIRTCFCollimation.dat the following day.
(also adjusting focus and astigmatism by hand)
collimate_once 014 looks good
10:58 Why did the guider image jump at the rotation offset of zero?
11:03 Lost star during the offset. Why?
11:05 ACQUIRE preset to M5 star IE=-114 CA=-139 (but that included some manual pointing offsets)
11:08 ACTIVE preset
Alignment of remounted M2
11:11 ACQUIRE preset to pointing star
Clear global offsets; Clear manual pointing; Clear Active Optics XYZ
M2 Tip -80
Move CA to -139
Manually apply -N000 Z7 and +M000 Z8
M2 Active Optics X=-2.795 Y=-4.658 RX=485 RY=-291
ptreset back to default IE=-43 CA=-124
M2 Tip=-84 Tilt=-24 ---> Manual Pointing X=1.226 Y=+4.290 RX=-825 RY=236
Success! (It is within range.) Need to sum Active Optics and Manual Pointing for the new Global Offsets.
New Global Offsets for DX M2 collimation are: X=-1.569 Y=-0.368 Z=0 RX=-340 RY=-55
JMH- The following day: Those Global Offsets were installed in DXSMIRTCFCollimation.dat and all the other DXSM* files.
Beware that this right side collimation LUT could have a large binodal term with elevation that we need to remove.
Refinement of the Pupil Wobble adjustment
11:39 ACTIVE preset to BS -- seeing is down to 0.5 arcsec on guider
Results of above are peculiar, so we will collimate and try again. See the red curve in the plot below.
12:00 ACTIVE preset to clean up the pupil a bit.
Results of above are also peculiar. The pupil locations are extended in the X-direction, but not Y.
- Pupil Wobble at RFBG:
12:20 close for impending dawn
- 03 Sep 2013