From: Russet McMillan
Subject: 3.5m Night Log 20000607
Date: Thu,  8 Jun 2000 05:35:57 -0600 (MDT)
                          WEDNESDAY JUNE 07 2000
                         APACHE POINT OBSERVATORY
                              OBSERVING  LOG
                                                          ACTUAL
ASTRONOMER      OBSERVER(S)        INSTRUMENT   DATE   START FINISH
Kron		Wilhite, Kron      DIS-M,2.0  6/7-6/8  20:30  04:05
Turner		McMillan           SPIcam       6/8    04:30  04:52
 INST        SCHEDULED     WEATH     EQUIP      OBS    DAY   NOTUSED
I/RS/DN    START FINISH   D    B    D    B    D    B   USE   D    B
UC08/S	   21:13 04:17    0   1.0   0    0   3.2  2.9   0    0    0
PU05/S	   04:17 04:52    0    -    0    -   0.6   -    0    0    -
(note: times listed include instrument change time)
                              ACTIVITY LOG
(* means a trouble report has been issued or appended to)
Observing Specialist: McMillan
The night was partly cloudy for the most part, with a few hours of
clear sky during second half.  The telescope was closed from 22:50 to
23:50 due to clouds.  The seeing was good to moderate during first
half (1 arcsec on the guider, and about 1.2 arcsec on the DIS
slitviewer), gradually degrading to 2 arcsec near morning twilight.
The guider seeing was generally comparable to DIMM (also to DIMM2 and
the 2.5m), but the slitviewer was getting somewhat larger FWHM.
A dark pattern, possibly due to dust, was very noticeable on the cloud
camera images when the sky was clear.  When clouds were present, this
pattern was less obvious because of the different grayscale stretch
for the images.  It may have started some time over the last few
nights without being noticed due to the persistent clouds.
* During checkout, the clamps on the tertiary rotator failed to close
when the mirror was first moved away from stow.  On a second attempt,
they worked normally.  Later in the evening, the light on the stop
button in the control room stopped working, although the stop button
itself was still functional.
The telescope and instruments behaved well.  The grating zerosteps
were correct after the instrument was mounted (and homed twice),
without a need for recalibration.  The guider failed twice during
offsets.  A few overshoots of the rotator occurred, but they were
small and self-correcting.
While DIS was in use, the pointing was good but not excellent.  I
experimented with zeroing out the guider offsets on some slews to see
if it would improve the pointing.  When the observers had many targets
in the same part of the sky (first several on the meridian in the
south, then several in the north), zeroing the offset seemed to reduce
but not eliminate the drift I saw accumulating in consecutive slews.
Zeroing the offset after a long slew did not help, often moving the
star at right angles to the direction it needed to go.  I think this
may point to some sort of slippage in the rotator; it could be
partially corrected by a guider offset in altitude and azimuth only as
long as the telescope stays in the same part of the sky.  On long
slews, when the rotator angle becomes very different, the guider
offset is no longer appropriate.
		            OBSERVER COMMENTS
                                FOCUS LOG
Time	Instrument   Focus     Az  El   #Temp    Dir MPH filt FWHM "
20:50  DISslit     275(1118)  177  61 14.4/16.8  145  18  --  1.27
20:55  Guider      775(1118)                                  1.1
04:20  SPIcam      125(726)   127  47 12.6/11.9  175  16  r'  1.49
#First temp is air, second temp is telescope.
                                 WEATHER
                               Wind
     Time   Temp F Dewp F  MPH  Direction    Dust      Sky      Precip.
     17:01    66    31      0   321  (NW)     488    ptly cldy   none
     18:01    65    34     11   242  (WSW)    512   mstly cldy   none
     19:01    63    33      3   162  (SSE)    593   mstly cldy   none
     20:01    59    39     14   134  (SE)     715    ptly cldy   none
     21:01    58    39     15   142  (SE)     782    ptly cldy   none
     22:01    58    38     15   134  (SE)     787   mstly cldy   none
     23:01    57    35     16   132  (SE)     749   mstly cldy   none
     00:01    56    31     19   137  (SE)     945    mstly clr   none
     01:01    55    31     17   132  (SE)    1005    mstly clr   none
     02:01    54    33     20   140  (SE)    1095    ptly cldy   none
     03:01    54    35     21   159  (SSE)   1116   mstly cldy   none
     04:01    53    36     12   178  (S)      989    ptly cldy   none
     05:01    53    36     11   173  (S)     1082    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
> 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: 2.55b5.
Current guide software version: GIm Ctrlv3.0b27.  Current TCC version:
2.2.9.  Current MC version: 1.7.2.
- Russet McMillan