Date: Wed, 24 Feb 1999 06:45:34 -0700 (MST)
From: Russet McMillan
Subject: 3.5m Night Log 990223
                        TUESDAY FEBRUARY 23, 1999
                         APACHE POINT OBSERVATORY
                              OBSERVING  LOG
                                                          ACTUAL
ASTRONOMER      OBSERVER(S)        INSTRUMENT   DATE   START FINISH
Staff         Gloria, McMillan      SPIcam    2/23-24  19:18 05:15
 INST        SCHEDULED     WEATH     EQUIP      OBS    DAY   NOTUSED
I/RS/DN    START FINISH   D    B    D    B    D    B   USE   D    B
EN01/R     19:18 05:15    0    0    0    0   3.3  6.7   0    0    0
(note: times listed include instrument change time)
                              ACTIVITY LOG
(* means a trouble report has been issued or appended to)
1st half observing specialist: Karen Gloria
The telescope was opened at 17:30 MST.  We had excellent seeing at the
beginning of the night.  I got several sub-arcsec images both with the
guide camera and SPIcam.  Sometime between 19:00 and 20:00, the seeing
"went south".  FWHM were close to 2 arcsec for a while.  The seeing
improved to around 1.3 arcsec towards midnight.
I spent most of the evening recollimating the telescope.  This just
involves retilting the secondary mirror.  I found, however, that the
tilt values we have been using are the best as far as I was able to
determine.
I took a few SPIcam images in the northern part of the sky to compare
with the fwhm measurements coming out of the seeing monitor.
A pointing model sequence was started shortly before midnight.
2nd half observing specialist: Russet McMillan
The pointing model finished around 01:00, and the results looked good
(RMS error less than 5 arcseconds), so I saved it under both naming
conventions as TELMOD.DAT;91 and TELMOD_NA2.DAT;91.
After that, I moved to the north pole to do some seeing tests that
could be compared to the DIMM seeing monitor.  Even using the same
minute-long exposure times as DIMM, the 3.5m seemed to get
consistently better seeing, by about 0.3 to 0.4 arcseconds.  After
some thought, I realized that the DIMM telescopes were looking
directly over the output of the intex fans that draw air from the
enclosure.  I turned the fans off and continued taking measurements.
The DIMM seeing improved a little and the telescope seeing degraded,
but they were only really in agreement when the 3.5m was clearly out
of focus due to a temperature change.  After I refocused, the 3.5m was
getting sub-arcsecond seeing, again better than the seeing monitor.
Later, when I turned off the fans in order to move the tertiary for
WSMR, the seeing monitor showed no appreciable change.
At 04:00, the WSMR folks started up their program and continued until
after dawn.
                            OBSERVER COMMENTS
                                FOCUS LOG
                             FEBRUARY 23 1999
						 Wind
Time   Inst        Focus     Az  El   #Temp    Dir  MPH  filt  FWHM "
18:30 guider  52639(6131)   188  58  3.6/4.7   278   7   R+ND2  1.1
19:00 SPIcam   -175(6014)   353  66  3.7/4.3   265   5    R     0.83
20:10 SPIcam   -275(6020)     0  34  4.5/3.4   265   7    R     1.7
20:20 guider  50486(6000)     1  36  4.5/3.3   269   9   R+ND2  1.8
20:55 SPIcam   -225(5964)    12  52  4.8/3.2   260   7    R     1.2
22:50 SPIcam   -175(6019)   355  53  4.4/3.5   287   9    R     1.4
01:20 SPIcam   -225           0  34  4.6/3.8   303  16    R     0.97
01:25 SPIcam   -200           0  34                       R     1.2
01:35 SPIcam   -225(6088)     0  34  4.4/3.8   308  17    R     1.02
01:50 SPIcam   -215(6100)     0  34  4.7/3.7   319  17    R     1.09
03:10 SPIcam   -300(5984)    -1  34  3.0/2.7   289  11    R     1.09
05:15 AMBER     275(6025)   237  68  3.2/2.7   331  13   none    ?
#First temp is air, second temp is telescope.
                                 WEATHER
                             FEBRUARY 23 1999
                               Wind
     Time   Temp F Dewp F  MPH  Direction    Dust      Sky      Precip.
     16:01    44     3      5   272  (W)      334    cirrus      none
     17:01    43     1      6   285  (WNW)    409    cirrus      none
     18:01    39     0      8   307  (NW)     225    cirrus      none
     19:01    39     0      5   265  (W)      369    cirrus      none
     20:01    40    -1      6   257  (WSW)    340    cirrus      none
     21:01    40    -1      8   264  (W)      499    cirrus      none
     22:01    40    -2     10   285  (WNW)    402    cirrus      none
     23:01    40    -1     11   304  (NW)     658    cirrus      none
     00:01    39    -2      8   299  (WNW)    743    clear       none
     01:01    40    -1     11   321  (NW)     654    clear       none
     02:01    40    -1     14   323  (NW)     532    clear       none
     03:01    37    -4      8   317  (NW)     739    cirrus      none
     04:01    39    -2     11   334  (NNW)    517    cirrus      none
     05:01    39     1     12   323  (NW)     453    cirrus      none
     06:01    38     6      9   343  (NNW)   1001    cirrus      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
> 1 micron per 0.1 cu. ft.
                             TELESCOPE STATUS
Primary, secondary, and tertiary mirrors in place and collimated.
Primary support system operational.  Mirror ventilation system in
place.  Telescope drives operational.  Current Remark version: 2.52
Current guide software version: GIm Ctrlv3.0b17.
- Karen Gloria, Russet McMillan