Date: Sat, 5 Jun 1999 05:37:00 -0600
From: long@apo.nmsu.edu (Dan Long)
Subject: 2.5m obslog 990604 ( MJD 51334 )
                           FRIDAY JUNE 4, 1999
                     APACHE POINT OBSERVATORY SDSS 2.5m
                              OBSERVING  LOG
    Observering team:   Dan Long                (APO)
                        Jeff Hayes              (APO)
                        Ellyne Kinney           (APO)
                        Matt Newcomb            (CMU)
   Tonight we verified that the pointing model seems to be quite good, and
that there are some bugs in the instrument block generation code.
   Opening was delayed tonight due to high winds and dust.  Things settled
down to openable levels by a little after 23:00.
   At this time we needed to take the imager off ( which had been put on
the telescope so it could be pumped during the day ), and put cartridge one
with the field L plate.  This took a couple of hours to complete.  Some
extra fiddling was involved, including having to swap kinematics from the
EC once the corrector was installed, and putting them on cartridge one.
   There was some trouble in removing the imager.  The SW protection bolt
had not been entirely removed, when we started lowering the camera.  Once
it was about an inch down, I noticed a discrepancy in the weight shown on
the lift control.  It was registering around 800 lb, instead of 1200 lb.
The camera however did not appear tilted at all.  We took the camera back
up and removed the bolt.  An inspection of the bolt and mount didn't show
any damage.  This demonstrates that the inability to see the bolt due to
the mounted spectrograph is a problem.
   The cartridge and corrector were mounted, and the balance was set.  The
counterweight setting was 380.
   There was a power outage on site during the day which necessitated
homing the primary and secondary ( the controllers are not on UPS power ).
I had to power cycle the secondary controller in order to be able to talk
to it.  I got no response at all to a HOST or telnet session.  It would
connect but nothing more.
                                MIRROR NUMBERS
   Primary:
   setmir:  0   3.9   -2.3   -128.1   -213.5
   galil:   4350 -1750   0 -16300  -11550  -11450
The linear gauges after setting to above position and relaxing
   1.9330
   0.5540
   0.5560
   0.4225
   1.8835
   0.3840
   Secondary:  30 deg El.  Spectro as instrument
      SecOrient= 3875, -320, -100.0, -50.0, 275
      galil:  4819050, 4559989, 4925036, -21696, -27432
   I set the altitude and rotator fiducials inside the enclosure while
waiting to open.  The azimuth was done later.
        Az:     120:45:44.756
        Alt:     14:53:07.724
        Rot:      0:59:42.970
  We got setup on field L by about 02:30.  The new pointing model appears
quite good, as stars showed up in some of the fibers with no offsetting!
For an elevation of 42 deg and azimuth of about -50 the calibration offsets
which brought all the stars in were -.002, -.0015, -.105.  The rotation
offset seems a little higher than usual.
   Best focus was at a piston of around 4000. I updated the spectro
instrument block to reflect this offset, so the focus value should be
around zero when the spectro inst block is set in future runs.
   Matt and I attempted to generate an instrument block for this field.  We
ran into trouble with the positions of the fibers.  When we would generate
the block info, it would put all zeros for the positional offsets.  We
didn't notice this until we attempted guiding and the GUIDE process died on
the first update.  Matt traced this to a formatting problem in the files
which supply the offset info.
   Unfortunately the field was too low to try anything by the time this was
sorted out.  The telescope was closed at about 04:20.
   One thing to note is that the stars stayed in the fibers and drifted
very little in the hour and a half we were tracking it; another indication
that the pointing model is pretty good.
                                WEATHER
   Weather tonight was clear or mostly clear all night.  Winds were
southwesterly at 15 to 30 MPH, temperatures were 7 to 10 C, the dewpoint
depression was between 15 and 32 C, dust counts started the night over
10,000 and ranged between 1000 and 1500 after midnight.
                                  Dan