From: Russet McMillan
Subject: 3.5m Night Log 20050221
Date: Tue, 22 Feb 2005 06:23:33 -0700 (MST)
                        Apache Point Observatory
                        3.5m Telescope Night Log
                        Monday, February 21, 2005
                                                         ACTUAL
 ASTRONOMER      OBSERVER(S)            INSTRUMENT     START FINISH
 --------------------------------------------------------------------
 M.Klaene        J.Barentine,C.Loomis,  S-H            18:30  19:55
                 W.Ketzeback,R.McMillan WIYNSpeed      19:57  23:00
                                        NIC-FPS        05:15  05:45
 A.Seth          A.Seth,K.Covey         NIC-FPS        --:--  --:--
  INST     SCHED(TWILIGHT)   WEATH     EQUIP     OBS     DAY  NOT USED
 I/RO/DN     START FINISH   D    B    D    B    D    B   USE   D    B
 ----------------------------------------------------------------------
 EN01/O      18:48  00:10   0   0.7   0    0    0   4.7   0    0    0
 UW15/R      00:10  05:45   0   5.6   0    0    0    0    0    0    0
  note: scheduled times listed include instrument change time
                ------------- ACTIVITY LOG --------------
 1st Half Observing Specialist: J.Barentine
 Engineering.  The night starts out with a thin layer of cirrus over the
whole sky.
 1) Altitude PID loop
    Using the Shack-Hartmann video camera, we verified the behavior of the
altitude tracking which moves the image of a star back and forth a small
distance (~1 arcsec) in altitude.  We attempted to tune out the motion by
changing the parameters of the PID loop that regulates the altitude motor
motion.  For later reference, we videotaped the output from the camera
starting at approximately 01:46:20UT.  We tried a couple iterations of
changing the PID parameters and checked results by monitoring stars at
different altitudes and parts of the sky (where the rate of tracking in
altitude varies).  Stopped recording at 02:52:50UT.
 2) WIYNSpeed tests
    Switched to the visiting WIYNSpeed high frame-rate camera just before
20:00 for gathering test data.  We began with verifying the validity of
the instrument block taken during recent engineering.  Then we took
time-series data on brightish stars under varying arrangements of
guiding/not guiding and telex fans off/on to study image motion while
tracking on the sky.
 Thicker clouds moved in toward 23:00 and shortly thereafter the sky was
more or less overcast.
 2nd Half Observing Specialist: R.McMillan
 Second half had thick clouds nearly the whole time.  The observers,
 needing 2 hours on-sky to get usable science, gave up around 04:30
 while I awaited the inevitable pre-dawn clearing.  After 05:00, the
 clouds thinned and I was able to do some tests of image quality with
 NIC-FPS to see how much the recent tracking irregularities might
 affect imaging.  I found that about 10% of 10s exposures were
 affected but probably still usable.  20% of 20s exposures were
 affected, and half of those were perhaps unusable.  The fraction may
 increase for longer exposures.  I had to stop testing for the
 inevitable humidity increase which accompanied the pre-dawn
 clearing.
                      ------- FAILURE LOG -------
  PROG   INST   FAILURE MODE     TIME
      (SEGDFNVO)    TI/SHU   START  FINISH  DESCRIPTION
 -----------------------------------------------------------------------
                 ---------------- FOCUS LOG ---------------
                                        Air/Truss   Wind
 Time   Instrument   Focus     Az  El    Temp-C    Dir MPH  filt  FWHM
---------------------------------------------------------------------
 21:03  wiynspeed *500(1177)   299 67  2.9/2.2    224  9    -     0.62
 05:11 NICFPS      125(1364)   169 72  1.3/1.6    253  12   H     0.75
 * The instrument zeropoint was changed after this measurement.
                ------------- WEATHER LOG ----------------
                                   Wind                      Precip.or
     Time   Temp F Dewp F  MPH  Direction    Dust    Sky    Conditions
     ------------------------------------------------------------------
     16:01    43    21     12   221  (SW)          MstlyClr    none
     17:01    40    24      9   196  (SSW)         MstlyClr    none
     18:01    36    21     11   190  (S)           MstlyClr    none
     19:01    35    24     14   217  (SW)          MstlyClr    none
     20:01    37    21     12   220  (SW)          MstlyClr    none
     21:01    37    24      9   200  (SSW)         MstlyClr    none
     22:01    38    25      5   205  (SSW)         MstlyClr    none
     23:01    38    26     12   212  (SSW)         MstlyCldy   none
     00:01    38    27     20   218  (SW)         mstly cldy   none
     01:01    37    28     13   221  (SW)         mstly cldy   none
     02:01    37    27     13   207  (SSW)        mstly cldy   none
     03:01    36    27     10   240  (WSW)        mstly cldy   none
     04:01    36    27     13   264  (W)          mstly cldy   none
     05:01    35    27     10   259  (W)           ptly cldy   none
     06:01    33    28      9   267  (W)           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.
     Note: The Tower Dust counter appears to be down at this time
                              TELESCOPE STATUS
      Telescope drives operational. Current Remark version: 2.85b
      Current TCC version: 2.7.2  Current TUI version: TUI 0.94b2