UT 20130902 Technical Observing - AGW1 Alignment and Calibration 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)

Summary

We made decent progress aligning AGw1 until humidity closed us at 6UT. We completed the alignment of the AGw1 guider probe to the rotator center. We were interrupted by the humidity during the step of adjusting M3 tip-tilt to minimize the pupil wobble. We struggled most of the night getting the M3 tilt correct. We had some problems because our improved measurement technique converged to slowly. We also had problems with running out of M3 Tilt travel and having to reposition the selector. We did get a clean minimum pupil wobble at the very end of the night.

Doug M found a problem where some unknown task is blocking the AOS connection to AdSec DX. See Issue 4779. It turned out to be a stray task from Chris Cox downtown.

We have NOT checked LUCI1 focus wrt AGw.

The next LFBG activity should be to set the rotator zeropoint on sky.

Preparations

Dave T. worked on LUCI1 checkout.

Olga worked on MODS1 checkout (and found detector readout problem).

Mtn crew put the door on the SX cell (it was open last night).

Dan C improved the ECSGUI.

Details

Open

02:20 Open in partly cloudy skies. No problems opening, but the display on ECSGUI still has issues.

02:28 ACQUIRE preset with LUCI1 EL=74 - confirm that the large mis-pointing is similar to last night. Will use M3 motion to recover the pointing....

02:39 TRACK preset with LUCI1

Use LUCI1 image to adjust pointing back toward nominal. We adjusted the SX M3 Tip-Tilt to get close to the nominal pointing model (which is working for MODS1). This helped the LUCI pupil alignment considerably.
SX M3 Global Offsets Tip=+450 Tilt=-1000 (near negative limit) Absolute: Tip=-416 Tilt=-184 Piston=0 RZ=+25.959
(See additional adjustments below.)

02:56 ACQUIRE preset - pointing is also better. Now recenter with IE=-66 CA=-40

03:05 ACTIVE preset - sextractor had trouble acquiring the defocussed donut. Converges to 0.65 arcsec FWHM

AGw1 Probe - Rotator Center Alignment @LFBG

Detailed instructions are in BGTechProcedures

03:20 TRACK preset to BS9178

setxy -u 1 -x 0 -y 612.5

/lbt/work/lbto/20130902_agw1/

readGuideCam left -e 1000 ----> 001 BUT THIS DOESN'T WORK BECAUSE /lbt/work is not mounted on tcs4

/home/lbto/work/20130902_agw1/

readGuideCam left -e 1000 ----> 001

Start Mirror Ventilation

03:33 ACTIVE preset to BS9178 at EL=52.8 -- seeing has improved to 0.5 arcsec FWHM on guider (0.635 on wfs)

03:39 TRACK preset

setxy -u 1 -x 0 -y 612.5

readGuideCam left -e 80000 ---> 002

old values from 20120204 in LUCI_L.cfg
guidecam_hotspot_x      255.0
guidecam_hotspot_y      230.0

lbto@obs2:53 % readGuideCam left -e 80000

left: acquiring full guider image ...
GCS side: L
exposureTime = 80000 ms
AzCam server timed out waiting for full CCD readout
guide image invalid!
Exit 255

On the next image the rotator screwed up.......Murphy is back in the building!

03:48 ACTIVE preset

[telescope@agw0 ~]$ getfocus -u 1 Focus position: 30.988000

[telescope@agw0 ~]$ getxy -u 1 Guide probe position

x

0.220000

y

612.136000

03:52 TRACK preset

[telescope@agw0 ~]$ setxy -u 1 -x 0 -y 612.5

[telescope@agw0 ~]$ getxy -u 1 Guide probe position

x

0.029000

y

612.500000

[telescope@agw0 ~]$ getfocus -u 1 Focus position: 0.001000

[telescope@agw0 ~]$ setfocus -u 1 -p 30.988 Command successfully transmitted!

ptincrement 0 CA -5

03:55 readGuideCam left -e 80000

readGuideCam left -e 80000

left: acquiring full guider image ...
GCS side: L
exposureTime = 80000 ms
AzCam server timed out waiting for full CCD readout
guide image invalid!
Exit 255

ds9 /home/lbto/work/20130902_agw1/left_guider000005.fits ---> 126,127.5 and accounting for binning ---> 252,255

04:09 home the AGw1 stages, and collimate M1 and M2, and put probe back in middle (to check this relatively large change)

04:13 readGuideCam left -e 80000

ds9 left_guider000006.fits ---> 128.5, 128 ---> result is confirmed

update ooffset for AGw1 RAD by increasing it by 1200 microns from 416855 to 418055 (did not change limits).

04:29 Stop GCSs, stopAGW, stop and restart oacserver, wait 30 sec, startAGW, wait 1 min, Start GCSs

04:36 ACTIVE preset humidity is up to 83% and seeing has increased to 1.1 arcsec.

04:40 TRACK preset

setxy -u 1 -x 0 -y 612.5; setfocus -u 1 -p 30.988

04:43 readGuideCam left -e 90000

AzCam server timed out waiting for full CCD readout
guide image invalid!

I think the first image after the last GCS thread has taken an image fails.......so you always need to take a test image after the active preset. (but perhaps this is not true for wfs images)

Collimate M1 and M2 and try again

04:49 readGuideCam left -e 90000

ds9 left_guider000008.fits ---> 126.5, 110 ---> 253, 220 (too far by 5 pixels modulo the measurement uncertainty)

update ooffset for AGw1 RAD by decreasing it by 200 microns from 418055 to 417855 (did not change limits).

04:59 Stop GCSs, stopAGW, stop and restart oacserver, wait 30 sec, startAGW, wait 1 min, Start GCSs

ptincrement 0 CA -5

ACTIVE

ACQUIRE

05:10 TRACK

05:12 readGuideCam left -e 90000

ds9 left_guider000009.fits ---> 129, 113.5 ---> GOOD

Checking the AGw1 wfs Hotspot Position

05:20 ACTIVE preset off-axis to a fainter guide star gs=3

Used setHotspot command to drive around and confirm hotspot position of 255,230.

(On AGw1, +Y moves stars down of the wfs image, +X moves the stars to the right wrt/lenslets.)

AGw1@LFBG Pupil Wobble Measurement

05:36 ACTIVE preset to a new target BS9183 at EL=64

Allow ACTIVE optics to collimate, then Stop WFSing

/home/aoeng/Desktop/data/sh_pupil_wobble/

SX M3 Global Offsets Tip=+450 Tilt=-1000

05:42 pupil_collect

0.00000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000003.fits
60.0000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000004.fits
120.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000005.fits
180.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000006.fits
240.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000007.fits
300.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000008.fits

We got 1 set of data that says the pupil is wobbling by 10 pixels. (We were previously able to adjust the wobble down to ~2 pixels.)

---

Close

05:57 Close for humidity as we move above 95%

Open

06:44 Open again

06:45 ACTIVE preset to BS9183 at EL=58

StopWFSing; block guiding

---

Move SX M3 Tilt from -1000 to -800 arcsec in steps of 50 while compensating with IE/CA. Tip remains +450.

resume guiding

06:54 pupil_collect

0.00000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000009.fits
60.0000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000010.fits
120.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000011.fits
180.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000012.fits
240.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000013.fits
300.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000014.fits

Doug is analyzing the images. The above set had a diameter of 5 pixels, so that was the correct sign of tilt correction (fortunate because it was away from the limit).

---

07:05 Move SX M3 Tip from 450 to 650 arcsec in steps of 50 while compensating with IE=-75 CA=-14. Tilt remains -800.

07:08 pupil_collect

What does this mean displayed on GCSGUI? "GCS is guiding but PCS is not accepting g"

see IT #4781 https://lbt.issuetrak.com/Issue_View.asp?IssueNbr=4781

0.00000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000015.fits
60.0000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000016.fits
120.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000017.fits
180.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000018.fits
240.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000019.fits
300.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000020.fits

The above set had a diameter of 7 pixels, so I went the wrong way in Tip (so much for tonight's lottery ticket).

---

07:44 Move SX M3 Tip from 650 to 250 arcsec in steps of 50 while compensating with IE=-90 CA=-44. Tilt remains -800.

07:45 pupil_collect

0.00000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000021.fits
60.0000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000022.fits
120.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000023.fits
180.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000024.fits
240.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000025.fits
300.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000026.fits

The above set had a diameter of 8 pixels.

---

08:22 Move SX M3 Tilt from -800 to -600 arcsec in steps of 50 while compensating with IE= CA= Tip remains +250.

08:23 pupil_collect

0.00000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000027.fits
60.0000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000028.fits
120.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000029.fits
180.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000030.fits
240.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000031.fits
300.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000032.fits

The above set had a diameter of 8 pixels.

---

08:34 ACQUIRE preset to BS9104 at EL=50 IE=-95 CA=-49

08:40 ACTIVE preset on-axis to BS9104

08:46 Move SX M3 Tip from 250 to 100 arcsec, and Tilt back from -600 to -800 arcsec. IE=-90 CA=-65. Absolute Tip=-766 Tilt=16.

08:49 pupil_collect

0.00000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000033.fits
60.0000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000034.fits
120.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000035.fits
180.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000036.fits
240.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000037.fits
300.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000038.fits

The above set had a diameter of 6+ pixels.

---

09:08 Star is lost. Why? Clouds?

09:14 resend ACTIVE preset

09:35 Move SX M3 Tip from 100 to 500 arcsec in steps of 50 while compensating with IE=-76 CA=-34. Tilt remains -800.

09:38 pupil_collect

0.00000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000039.fits
60.0000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000040.fits
120.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000041.fits
180.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000042.fits
240.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000043.fits
300.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000044.fits

The above set had a diameter of 7-ish pixels.

---

09:52 Move SX M3 Tip from 500 to 400 arcsec in steps of 50 while compensating with IE=-80 CA=-41. Tilt remains -800.

09:54 pupil_collect

0.00000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000045.fits
60.0000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000046.fits
120.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000047.fits
180.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000048.fits
240.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000049.fits
300.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000050.fits

The above set had a diameter of ~6 pixels.

---

Shifting strategy, picking a particular rotator angle and then adjusting M3 to drive its pupil position to the center of the circle. (Perhaps noiser than what we've been doing above, but converges mush faster.)

10:17 collimate_once 051

Move Tilt from -800 to -700 arcsec allowing the guider to recenter.

10:19 collimate_once 052

Move Tilt from -700 to -900 arcsec allowing the guider to recenter.

10:22 collimate_once 053

---

Move Tilt from -900 to -950 arcsec allowing the guider to recenter. Tip remains at +400. Absolute Tip=-466 Tilt=-134.

10:25 collimate_once 054

10:27 pupil_collect

0.00000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000055.fits
60.0000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000056.fits
120.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000057.fits
180.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000058.fits
240.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000059.fits
300.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000060.fits

The above has a diameter of 4 pixels.

10:41 collimate_once 061

---

Move Tilt to -1000

10:43 collimate_once 062

Move Tip to 550, Tilt remains at -1000 (near the software limit).

10:50 collimate_once 063

Move Tip to 475

10:52 collimate_once 064

Move Selector Global Offset from 0.0 to -0.2 deg (lost the star) to give an absolute value of +25.760. Tip and Tilt remain +475 and -1000.

ACQUIRE preset IE=-100 CA=-22

ACTIVE preset

11:07 collimate_once 065 (wrong direction)

Move Selector Global Offset from -0.2 to +0.2 deg absolute +26.160

ACQUIRE preset IE=-42 CA=-47

11:16 ACTIVE preset

11:18 collimate_once 066

Does Chris have wrong sign tool tips on Global Offsets? (different for SX/DX?) SX seems wrong as we needed +RZ to get more negative tilt.

---

Move SX M3 Global Offset Tilt from -1000 to -750 arcsec (with the new selector angle)

11:25 collimate_once 067

Move SX M3 Global Offset Tilt from -750 to -650 arcsec (with the new selector angle)

11:30 collimate_once 068

11:34 pupil_collect -- failed/killed after 2 or 3 images as we lost the star (due to clouds?)

ACQUIRE preset didn't see anything

11:41 ACQUIRE preset to WT10_210 at EL=58 IE=-52 CA=-47

11:44 ACTIVE preset to BS9108 at EL=63

11:48 pupil_collect

0.00000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000072.fits
60.0000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000073.fits
120.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000074.fits
180.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000075.fits
240.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000076.fits
300.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000077.fits

The above has a diameter of 7 pixels.

Move SX M3 Global Offset Tip from 475 to 250 arcsec. Tilt remains at -650.

12:06 collimate_once 078

Move Tilt from -650 to -525 arcsec. Tip remains at 250.

12:11 collimate_once 079

12:13 pupil_collect

0.00000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000080.fits
60.0000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000081.fits
120.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000082.fits
180.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000083.fits
240.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000084.fits
300.000	/home/aoeng/Desktop/data/sh_pupil_wobble/left_wfsc000085.fits

The above has a diameter of 1.5 pixels.

Final SX M3 Global Offsets for LFBG Tip=+250 Tilt=-525 RZ=+0.2. Absolute: Tip=-616 Tilt=+291 RZ=+26.160 These were saved to SXTMLUCIFERCollimation.dat the following day.

OSS is using this base position:

oss.side[0].terc.focal_stations.bentGregorianFront              map  0:-865.99  1:815.90 2:0.0  3:+25.96

A Summary of the pupil position measurements is in pupil.dat, and can be seen in the attached plot.

An Improved Procedure for Measuring and Converging on Pupil Wobble

Based on Tonight's Experience we think the following is the most expeditious way to measure and adjust pupil wobble.

• ACTIVE preset on-axis, and stopWFSing.
• pupil_collect to capture a set of 6 wfs images at different rotator angles (use diameter of this circle to measure the wobble)
• choose just one of these pupils at some rotator angle, and adjust M3 tip-tilt to move the pupil to the center of the above circle (For now - until we are more clever about the rotator angle mapping - taking single pupil images provides a more efficient convergence to minimum wobble.) Use collimate_once, /send, /dont_ask
• pupil_collect to take a confirmation set of 6 wfs images

-- JohnHill - 02 Sep 2013

• Pupil Wobble at LFBG: