PEPSI Night #3 UT 20190123

OSA: S. Allanson

Observers/ISA: J. Hill (Tucson)

Software: P. Kubanek

ISp:

Mtn Manager:

Summary

The start of the night is a PEPSIPFU transit observation. After that we'll switch to PEPSIPOL.

AGW4 hit the crash switch, so we never got to use RPOL tonight. Also the ADC on RPOL also failed again.

We found that AGW4 probe was mispositioned because the oacontrol.conf file was overwritten after 20180906.

John's latest thought is that GCS and IDL are hard to match because of the array of signs built into IDL. (see below)

Preparations

Probe Centering for AGW4

The thing that puzzles me is that on 20180906 UT with AGW4 at LFBG, I adjusted the guide probe theta encoder offset in order to shift the probe by approx 9 mm to be on the LFBG rotator axis. Unless the mounting holes on the PEPSI spider are off by 10 mm, I would have expected the 20180906 adjustment to be good for LDG too. So do we have the same error now? Or do we have the opposite error and we need to undo the September 2018 correction?

The file /lbt/oacontrol/current/etc/oacontrol.conf (as seen from oac@oac) is the WRONG one. That could explain this discrepancy from September if I have remembered the correct path.

We discovered tonight that the oacontrol.conf configuration file had been overwritten sometime in the multiple switches between oacontrol v4.4 and v5.0 and v5.1 so that the encoder adjustments to AGW4 and AGW2 that we made on 20180906 UT got lost.

This explains the mystery we found on Saturday of why the AGW4 guide probe was ~10 mm from the rotator axis. I expect now it will be a more normal +-2 mm from the axis.

I have replaced those changes (recorded in Commissioning/Com20180906) in the v5.1 version of the file /lbt/oacontrol/current/etc/oacontrol.conf

I've also checked that the new AGW1 transform installed on 20181101 is correctly in place.

I've run rdwrconfig -u 4 and rdwrconfig -u 2. We will restart both GCS subsystems when we switch back to PEPSIPOL in a couple hours.

Divergent Active Optics

I found this afternoon the PEPSIPOL_L.cfg and PEPSIPOL_R.cfg have opposite signs for SFP_rotation. Is that parameter actually used?

PEPSIPOL_L.cfg:SFP_rotation	90.0	
PEPSIPOL_R.cfg:SFP_rotation	-90.0
Switching one of them will change the sign of Z7,Z8 but will not change the sign of Z4,Z5,Z6. And maybe that variable isn't used for active optics. Compare WFS_rotAngleOffs

Details

These are John's notes about AGW3 and AGW4 active optics and collimations. This is not the observing log.

07:06 UT Restarted GCSs to read new oacontrol.conf parameters duriong the switchover from PEPSIPFU to PEPSIPOL.

07:25 UT Stop and restart AGW4 because probe wouldn't move.

07:3x UT put back the old oacontrol.conf and stop/start AGW4 again. Same motor following error.

07:40 UT Reboot oacontrol, and wait 10 minutes. Michael thinks we hit the crash switch. We abandon the right side as ADC is also out of service.

08:00 UT - tried collimate_gcs which ran, but didn't seem to be sending the zernikes.

08:10 UT - took 1 GCS wfs image off-axis

08:30 UT - collimating smoothly with IDL as long as JMH remembers to press stopWFS when a new preset is sent.

There is a little bit too much trefoil, so maybe our Zernike rotation angle is a bit off. Was also contaminated by Z13-21.

Ilya having problems with GCS hotspot locking up when he sends too large a correction (more than 0.5 arcsec?). I think this is a feature of the last non-sidereal work in 2017.

8:48 UT - Clear active optics on M1 as we sent some Z13-21 and were building up trefoil.

09:20 UT - Z5 runs away after I put in wfsc.zernike_factor

09:30 UT - correct version is this to preserve DG signs which are different than BG signs.
            agw_params[i].wfsc.zernike_factor = [ [0.0, 0.0, 0.0, 0.0, $                        ; Cow: Z0-Z3                                          
                                1.5, 1.7, 1.6, 1.4, 1.4, 1.7, 1.7, 1.3, $                       ; Cow: Z4-Z11                                         
                                0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.7], $       ; Cow: Z12-Z22                                        
                               [0.0, 0.0, 0.0, 0.0, $                                           ; Sext: Z0-Z3                                         
                                1.1, 0.8, 1.0, 1.0, 0.9, 1.0, 1.0, 1.5, $                       ; Sext: Z4-Z11                                        
                                0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.7] $        ; Sext: Z12-Z22                                       
                             ]
            agw_params[i].wfsc.zernike_factor *= right_direct_gregorian_sign
where the signs are:
    left_direct_gregorian_sign = [ [0.0, 0.0, 0.0, 0.0, $                                               ; Cow: Z0-Z3
                                    -1.0, -1.0, -1.0, 1.0, 1.0, -1.0, -1.0, -1.0, $                     ; Cow: Z4-Z11
                                    1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -1.0], $          ; Cow: Z12-Z22
                                   [0.0, 0.0, 0.0, 0.0, $                                               ; Sext: Z0-Z3
                                    -1.0, -1.0, -1.0, 1.0, 1.0, -1.0, -1.0, -1.0, $                     ; Sext: Z4-Z11
                                    -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0, -1.0] $ ; Sext: Z12-Z22
                                 ]

    left_bent_gregorian_sign = [ [0.0, 0.0, 0.0, 0.0, $                                          ; Cow: Z0-Z3
                                  -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, -1.0, -1.0, $                 ; Cow: Z4-Z11
                                  1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0], $      ; Cow: Z12-Z22
                                 [0.0, 0.0, 0.0, 0.0, $                                          ; Sext: Z0-Z3
                                  -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, -1.0, -1.0, $                 ; Sext: Z4-Z11
                                  -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, -1.0] $ ; Sext: Z12-Z22
                               ]

09:50 UT - Ilya working on his fiber centering code to use offsetTelescope rather than changing the hotspot.

-- JohnHill - 23 Jan 2019
Topic revision: r3 - 23 Jan 2019, JohnHill
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