From: Russet McMillan
Subject: 3.5m Night Log 20070530
Date: Thu, 31 May 2007 04:44:18 -0600 (MDT)
                         Apache Point Observatory
                         3.5m Telescope Night Log
                         Wednesday, May 30, 2007
                                                           ACTUAL
 ASTRONOMER     OBSERVER(S)             INSTRUMENT      START  FINISH
 --------------------------------------------------------------------
 M.Klaene       R.McMillan              SH,NA2gdr       20:15  02:30
  INST     SCHED(TWILIGHT)   WEATH     EQUIP     OBS     DAY  NOT USED
 I/ROW/DN   START  FINISH   D    B    D    B    D    B   USE   D    B
 ---------------------------------------------------------------------
 EN01/W     21:07  04:54    0    0    0    0    0   7.8   0    0    0
   note: scheduled times listed include instrument change time
                ------------- ACTIVITY LOG --------------
 Observing Specialist: R.McMillan
 With the az and alt drives both swapped out, we got on sky at sunset
 for some drive tuning.  Nick was present to see the magic of
 eliminating tracking errors via PID tuning -- but alas, there were
 no tracking errors to be seen.  Stars were rock solid on the SH
 video even when transiting at 84.7 degrees!  I checked many former
 trouble spots around the sky and found tracking was beautiful
 everywhere.  So I changed the PID loop parameters to favor low noise
 during slews and fast damping of perturbations.
 Next I took some Shack-Hartmann data for a quick collimation check,
 which turned out to be not so quick.  I couldn't reduce the data
 with tonight's reference frame, possibly because of an old familiar
 problem involving placement of the reference LED -- but the way in
 which the software choked on the reference frame was unfamiliar and
 unpleasant and cost me some extra time to figure out.  I got the
 data reduced with last month's reference frame and found the
 collimation was too near-perfect to bother adjusting.
 Next I took a pointing model, which had moderately large scatter.
 This may be related to the only warning flag I noticed during
 checkout, which was that magnesensor errors in azimuth were
 uncommonly large right after changing directions.  Before seeing the
 pointing model, Nick was planning to re-clean the driive surfaces
 tomorrow.  I favor that plan and suggest that possibly there will be
 time for another pointing model tomorrow night for comparison -- in
 any case, I do recommend lots of test slews with changes in
 (azimuth) direction followed up MS.DUMP.
 When the pointing model was done and I was setting up for Fastcam, I
 saw a lot of noise on the azimuth dataq during slews.  I tried
 changing the tune parameters around some more, without much effect.
 Finally I re-measured the velocity scale, which had been measured in
 the afternoon (no change from before drive swap) and by myself at
 sunset (very little change from before drive swap).  Now there was a
 large change, certainly more than the mild temperatures could
 account for.  I'm not sure what could have caused this delayed
 change, but updating the parameter got rid of the noise.  This
 couldn't by itself account for the scatter in the pointing model,
 since there was almost no noise in the first several slews, and the
 data don't show an increase in scatter over the course of the model.
 I finished up with some fastcam data under conditions that were
 pretty comparable to the set taken May 13 -- wind just a teensy bit
 stronger, star just a little higher in altitude.  Hopefully the two
 datasets will be similar enough for a good before/after comparison
 of the drives.
 Tomorrow night is open to spend time on Agile and SPIcam tests, with
 a pointing model as a low-priority fill-in, only if Nick feels he
 made some significant difference in cleaning the drives.  Watch
 az and alt currents closely on dataq, and re-measure velocity scale
 if strong noise patterns appear.  Check azimuth MS.DUMP frequently.
                       ------- FAILURE LOG -------
  PROG   INST   FAILURE MODE     TIME
       (SEDFNVOG)   TI/SHU    START  FINISH  DESCRIPTION
 ----------------------------------------------------------------------
               ---------------- FOCUS LOG ---------------
 Time  Instrument  Focus    Az  El  Temp Strc Prim  Sec  Air  filt FWHM
 ----------------------------------------------------------------------
                ------------- WEATHER LOG ----------------
                                   Wind                      Precip.or
     Time   Temp F Dewp F  MPH  Direction    Dust    Sky    Conditions
    -------------------------------------------------------------------
     16:00    64    13      5   262    (W)    637    clear     none
     17:00    67    16     11   270    (W)    778    clear     none
     18:00    63    14     10   299  (WNW)    768    clear     none
     19:00    61    16      9   264    (W)    759    clear     none
     20:00    57    19      7   224   (SW)    721    clear     none
     21:00    56    18      9   193  (SSW)    806    clear     none
     22:00    56    18     13   181    (S)    747    clear     none
     23:00    57    15     14   190    (S)    812 mstly clr    none
     00:00    56    15     10   213  (SSW)    889 mstly clr    none
     01:00    57    13     12   216   (SW)    774 mstly clr    none
     02:00    57    14     14   213  (SSW)    755 mstly clr    none
     03:00    55    15     11   218   (SW)    728 mstly clr    none
     04:00    54    15     10   207  (SSW)    795 mstly clr    none
     Note: the wind was coming from the azimuth listed.
     The convention used is north=0 degrees, east=90 degrees.
     The dust count is particles > 1u per 0.1 cubic feet.
                              TELESCOPE STATUS
      Telescope drives operational. Current TCC version: 2.9.0
      Current TUI version: TUI 1.3