Bent Gregorian Technical Observing with LUCIFER:
UT 2009 September 24

Observer: DThompson, MPedani, NAgeorges, MJuette, WSeifert (@LBT), DMiller (Tucson)
Telescope Operator: David Gonzalez-Huerta
SW support: NCushing, MDeLaPena (Tucson)

Summary

  • Thursday will start the LUCIFER commissioning run

  • Telescope not rebalanced after mounting LUCIFER - lost the 1 hour before sunset.
  • Two spontaneous shutdowns of GCS in rapid succession last night
  • Rotator hit some limit tracking into 438 degrees, but manually we can send it to 450.
    Is there an excessively conservative SW limit in there somewhere?

A busy and productive night...

  • LUCIFER rotational offset from PA = 0.047 (+/- 0.018) degrees.
    • LEFTZEROPOINT would be -187.656, but...
  • AGw transform aligned to LUCIFER columns to ~10 arcsec (0.1 pixel in 1666)!
    • No offset applied to LEFTZEROPOINT, no need to recalibrate AGw transform.
  • ROTCEN on LUCIFER at pixel 1014.1 1043.5 (ARC method)
  • Collimation model looks OK from 28 to 80 degrees
  • Pointing Model - collected 52 points.
    • LUCIFERSX.20090924.ptmod generated. Set as default for PCS
    • rms of fit is 3.75 arcsec with only simple model + tube flexure
    • LUCIFER computer found to be 124 seconds fast!
  • Field Aberration measurements collected in <1 arcsec seeing

Preparations

  • Marco, Norm, DGH, please spend some period of time tonight watching GCS and note the time when you see any corrupt images. See IT#2358.

Details

01:37 ~10 minutes post-sunset. Tair=5.3C RH=42.8% DewPt=-6C Wind=3.5 m/s max. Mirror is colder than outside. Telescope not ready. When LUCIFER was attached the telescope was not rebalanced, recovery took a while. 1h lost.

01:40 Opening dome.

01:50 LUCIFER sends preset with proper motions:
PCS logged 17:57:48.498 +04:41:36.25

02:10 Slew to WT10_198 to adjust pointing: New CA=-44 IE=-131

02:23 Slew to StoneM GS=44 Hit Mirror Limits X and Y at +51 EL

02:27 Slew to WT10_196 to adjust pointing again New CA= -44 IE=-143 Not sure this is the star

02:33 Slew to M5_0656 gs=0 Ok we see the star now

02:40 Slew to WT10_196 to adjust pointing again New CA= 12 IE=-58 Perfectly centered
LUCIFERSX.200909temp.ptmod edited to include these IE, CA, and PCSInstrument.conf modified to use this ptmod for LUCIFER.

02:43 Slew to StoneM GS=44

02:54 Testing LUCIFER DETXY offsets. +X does now move the source on the detector the correct direction, but we hit a -Y limit on M1 again. Offset +2mm to M1 and M2 and recheck pointing.

02:59 Adjust pointing on WT10_196. IE=-62, CA=11

03:00 pointto StoneMagw gs=44. Seeing on guider is ~1.5 arcsec.

03:01 LUCIFER DETXY offsets now with correct orientation

luci_20090924_0011 & 12 on StoneMagw at PA=352.45
luci_20090924_0013 at PA=10

03:18 pointto StoneOagw gs=17 PA=0 ... too faint
03:23 pointto StoneOagw gs=4 PA=0 ... luci_20090924_0014 & 15

03:31 pointto StoneAagw gs=16 PA=0 ... too low ! El=+19
03:37 pointto BS9182 gs=30 ... luci_20090924_0016
03:48 pointto BS9178 gs=146 ... luci_20090924_0017
03:53 pointto BS9183 gs=27 ... GCS GUI dies ... and GCS GUI dies again! ... luci_20090924_0018
04:00 pointto BS9185 gs=19 ... luci_20090924_0019
offset 10 10 ... luci_20090924_0020
04:08 AGW seeing = 1.3" T_air =5.6 T_mirror = 5.2
04:14 pointto BS9188 gs=15 ... luci_20090924_0021
offset 10 10 ... luci_20090924_0022
04:22 pointto BS9177 gs=19 ... luci_20090924_0023
offset 10 10 ... luci_20090924_0024

pointto BS9177 gs=19 PA=0 luci_20090924_0025
pointto BS9177 gs=19 PA=31 luci_20090924_0026
pointto BS9177 gs=19 PA=6 luci_20090924_0027
pointto BS9177 gs=19 PA=341 luci_20090924_0028
pointto BS9177 gs=19 PA=316 luci_20090924_0029
pointto BS9177 gs=19 PA=291 luci_20090924_0030
pointto BS9177 gs=19 PA=266 luci_20090924_0031
pointto BS9177 gs=19 PA=241 luci_20090924_0032

ROTCEN on LUCIFER from ARC test
The rotator center was found to be at 1014.06 1043.51 with an rms of ~1 pixel.

pointto BS9188 gs=15 PA= 210.09 luci_20090924_0033
pointto BS9188 gs=15 PA= 165.00 luci_20090924_0034
pointto BS9188 gs=15 PA= 255.00 luci_20090924_0035

ORIENTATION results
17 pointings fit with WCS at various position angles and over several different fields. The mean offset of the achieved position angle is 0.047 (+/- 0.018) degrees below the requested PA. The LEFTZEROPOINT could be updated to -187.656, but see below.

05:37 pointto StoneO gs=3 PA=203.6 to measure existing AGw transform on LUCIFER
luci_20090924_0036

offset 0 -120 luci_20090924_0037 (star unusable)
offset 0 120 luci_20090924_0038 (star unusable)
offset 0 -120 luci_20090924_0039 (ok)
offset 0 100 luci_20090924_0040 (ok)
offset 0 -100 luci_20090924_0041 (ok)
offset 120 0 luci_20090924_0042 (sky background)
offset 0 100 luci_20090924_0043
offset 0 -100 luci_20090924_0044
offset 0 100 luci_20090924_0045
offset 0 -100 luci_20090924_0046
offset 0 100 luci_20090924_0047
offset 0 -100 luci_20090924_0048
offset 0 100 luci_20090924_0049
offset 0 -100 luci_20090924_0050

OFFSET results
We offset +/- 100 arcsec from center, repeating the cycle 5 times. The mean positions at both ends were within 0.084 pixels in X over the 200 arcsec offsets. This is so close that I recommend not changing the LEFTZEROPOINT, and we do not at this time need to recalibrate the AGw transform.

Collimation model check
06:40 Lpoint C22+15 PA=0 Tel="TRACK" (check collimation at +61 EL)
luci_20090924_0050

luci_20090924_0051 fwhm=14.7 pixels
luci_20090924_0052 fwhm=9.5 pixels
seeing variable; collimation looks reasonable.

06:59 Lpoint 00+25 PA=0 Tel="TRACK" (check collimation at +80 EL)
luci_20090924_0053 (Collimation looks pretty good)

07:06 Lpoint 00-28 PA=0 Tel="TRACK" (check collimation at +28 EL)
luci_20090924_0054

07:15 Lpoint 00-00 PA=0 Tel="ACTIVE" (re-collimate before taking a pointing model)

Pointing Model Data 07:25 Start Pointing Model /home/telescope/20090924.ptlog

Pos 1 WT10_353 luci_20090923_0057
Pos 2 ACT_0404 luci_20090923_0058
Pos 3 ACT_0403 luci_20090923_0059
Pos 4 ACT_0336 luci_20090923_0060
Pos 5 WT10_270 luci_20090923_0061
Pos6 WT10_202 luci_20090923_0062
Pos7 WT10_240 luci_20090923_0063
Pos8 ACT_0087 luci_20090923_0064
Pos9 ACT_0155 luci_20090923_0066
Pos10 ACT_0278 luci_20090923_0065
Pos11 WT10_231 luci_20090923_0067
Pos12 WT10_344 luci_20090923_0068
Pos13 WT10_342 luci_20090923_0069
Pos14 ACT0_299 luci_20090923_0070
Pos15 ACT0_248 luci_20090923_0071
Pos16 ACT0_310 luci_20090923_0072
Pos17 WT10_208 luci_20090923_0073
Pos18 ACT_0089 luci_20090923_0074
Pos19 WT10_119 luci_20090923_0075
Pos20 ACT0293 luci_20090923_0076
Pos21 ACT0257 luci_20090923_0077
Pos22 WT10_236 luci_20090923_0078
Pos23 ACT0289 luci_20090923_0079
Pos24 WT10_338 luci_20090923_0080
Pos25 ACT0393 luci_20090923_0081
Pos26 WT10_401 luci_20090923_0082
Pos27 ACT0410 luci_20090923_0083
Pos28 ACT0340 luci_20090923_0084
Pos29 WT10_395 luci_20090923_0085
Pos30 WT10_381 luci_20090923_0086
Pos31 ACT0402 luci_20090923_0087
Pos32 ACT0411 luci_20090923_0088
Pos33 WT10_364 luci_20090923_0089
Pos34 ACT0380 luci_20090923_0090
Pos35 WT10_360 luci_20090923_0091
Pos36 WT10_362 luci_20090923_0092
Pos37 ACT0323 luci_20090923_0093
Pos38 ACT0293 luci_20090923_0094
Pos39 ACT0221 luci_20090923_0095
Pos40 WT10_149 luci_20090923_0096
Pos41 WT10_151 luci_20090923_0097
Pos42 WT10_189 luci_20090923_0098
Pos43 WT10_261 luci_20090923_0099
Pos44 WT10_191 luci_20090923_0100
Pos45 WT10_174 luci_20090923_0101
Pos46 WT10_108 luci_20090923_0102
Pos47 ACT_0176 luci_20090923_0103
Pos48 WT10_265 luci_20090923_0104
Pos49 WT10_297 luci_20090923_0105
Pos50 WT10_299 luci_20090923_0106 (Rotator reached limits 2 times!Pls check software and hardware limits. Which comes first?)
Pos51 ACT0286 luci_20090923_0107
Pos52 ACT0346 luci_20090923_0108

09:26 Pointing run done. 52 stars in 2 hours. Stop pointing log. Note that the rotator hit some limit at 438 degrees. but manually we can send it to 450. Is there a conservative SW limit in there somewhere?

Pointing model: LUCIFERSX.20090924.ptmod
rms of simple model fit (AZALT + Tube flexure) 3.75 arcsec. Implemented but unable to reall test before dawn. Set as default in PCSInstrument.conf. Lucifer computer found to be 124 seconds ahead of the TCS computers. This caused a problem with the new pointing model until realized and compensated for.

09:55 Corrected pointing (only CA, now 3.0) and collimation (FWHM ~0.9). Doug to take over and make aberration measurements.

Field measurements

10:07 pointto M5_1133 Telmode=ACTIVE. David set IE=-60.5 CA=3

10:15 pointto BS9107 TeleMode=ACTIVE. Several ActOpt iterations to collimate. Acquisition image had offset. Will reset IE and CA

10:20 pointto BS9107 TeleMode=ACQUIRE. No star found. Go to lower star (this was at 83 el)

10:30 pointto M5_0151 TeleMode = ACQUIRE. IE=-58 and CA=-1.5

10:35 pointto BS9105 TelMode=ACQUIRE. IE=-67.5 anc CA=-4

10:37 pointto BS9105 TelMode=ACTIVE wfsc 14,15 not sent. Had to register as Lucifer

10:50 My IDL routines are added coma to the collimation. Found that had the wrong value of agw_x_probe_flip (had -1, should be 1)

11:15 pointto BS9105 TelMode=GUIDE. Start collimating with IDL

11:20 looks to be diverging. (was that seeing got worse). Collimated with GCS. Getting exactly the same zenike value with IDL as with GCS.

11:25 pointto gs=16. Can see star in Acquisition image and GCS puts X marks the spot, but when GCS tries to guide with 5x5" box it can not find a star.

11:27 pointto gs=3. Star found

11:30 pointto gs=0. Collimate with IDL

BS9105
GS PA WFSC
0 149.8 24-26
3 262.89 27-29
0 262.89 30-32
6 337.51 33-35
0 337.51 36-39
21 77.41 40-42
0 77.41 43-44
22 132.06 45-47
0 132.06 48-49
2 303.62 50-52
0 303.62 53-55
18 46.45 56-58
0 46.45 59-60
3 262.89 61-63
0 262.89 64-65
7 344.36 66-67

Last one, 7, is too dim!

Not a bad set of data

On 26-Sep-2009 MST, Andrew wrote:

Here's the field data Doug took the other night. Haven't analyzed it yet, but there's a stand-out feature I'd be interested in your comments on: every single measurement of Z4 is negative.

So, we were collimating on-axis, measuring off axis, collimating on axis etc.

Temperature had been static for several hours. were looking at one elevation, not really changing elevation much over the measurements. The mirror was within 0.1 degree of ambient. So why the monotonic focus drift?

JMH: Temperature stability near 5.3 degC is confirmed by the attached plot. I think what you are seeing is that Doug is not updating the collimation between individual WFS measurements (only when he changes stars), so this is the normal effect of the telescope changing focus with elevation. See the collimation update times extracted from the TCS log in the following table.

Sep 24 11:26:22 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 11:28:52 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 11:30:46 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 11:33:30 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 11:38:14 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 11:41:43 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 11:45:41 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 11:48:45 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 11:53:49 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 11:57:04 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 12:00:24 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 12:04:29 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 12:07:22 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 12:11:17 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 12:15:25 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 12:19:01 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 12:22:22 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 12:26:07 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 12:29:11 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 12:33:18 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 12:37:18 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated
Sep 24 12:38:39 lbtmu303 LBT_PSFL: ACTOPT: Primary collimated

12:43 Closing dome.

Observing Plan

Closed dome
  • Test communication with TCS
  • Presets with proper motions [SW:B30t1] use highpm.cat
  • Discuss with Marcus dropping images onto archive [done]
  • Discuss with team astronomical applications for "IDLE" mode on rotator

Early in the night
  • Correct initial collimation/pointing

  • Check DETXY offsets in X - everything flipped as needed? [SW:B32t1]
    • positive X offset should move source right, positive Y moves up

  • Re-orient on sky (N accurately along columns at PA=0)
    • Need pairs of offset 30s images for skysub.
    • Persson stds or Stone fields OK
    • Keep WFS collimated
    • Take at least one field at two position angles

  • Re-measure AGw/Rotator center with ARC method
    • Use fixed on-axis source and guide star
    • Observe at multiple PAs spanning 120-160 degrees
    • 60s images (keep WFS collimated)

Middle of the night
  • Re-calibrate AGw transform [SW:B30t3]
    • use StoneOagw if you can get to this earlier
    • use StoneAagw field, but stars are faint so seeing must be good

  • Make new collimation model, implement (optional if it looks good)
    • Derive and implement before pointing model obs

End of the night
  • Make new pointing model, implement (if coll model good)
    • Have TO start the pointing log!
    • Check first position in AZ > 360 degrees wrap
    • Use ARC method to measure AGw/Rotator center
    • 28 points are sufficient, more is always better
    • Can use NB filter in LUCIFER, the pointing stars are ~7.5 mag
    • needs stable temps!

  • Test re-calibrated Instrument-AGw alignment
    • needs Jesper to make new transform first

Other SW tests
  • B30t2 verify tracking recovers from IDLE mode on rotator (do as LUCIFER?)
  • B28t1 new workstation astro SW all set up? (hushiraf)

Tasks not completed with IRTC: Field aberration measurements (DMiller)
  • Guide to 18th mag. Scaling from last night's observations, we should be able to guide at 18th mag only when the r' seeing in the guider is better than ~0.7 arcsec FWHM.
  • WFS on 18th mag. Will need to set the wfs max exposure time to 120s

-- DavidThompson - 23 Sep 2009
I Attachment Action Size Date Who Comment
daq.20090924.gifgif daq.20090924.gif manage 42 K 27 Sep 2009 - 00:51 JohnHill Plot of Telescope and Mirror Temperatures
Topic revision: r8 - 27 Sep 2009, JohnHill
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