From: "Pete Newman"
Subject: RE: 2.5m obslog 20040609 (MJD 53166)
Date: Thu, 10 Jun 2004 11:07:22 -0600
Dan & John reported:
>         Cartridge 7 1423   2.7  3.6  2.9  3.9
>
> 08:41Z  gotoField
> 08:55Z  preCalib
> 09:03Z  first science
>
>         Had to abort and call it bad due to sp1 XSIGMA and WSIGMA
>         being out of spec in the preCal.  sp2 was fine.
>         In an attempt to salvage something of the night we
>         issued a guess of -3000 mechPiston to sp1 and took another preCal
>
>         All this after checking collimation this afternoon with
>         the rotator at 45 degrees.  Harrumph, grumble, grumble.
The weather system recorded:
>                              Wind
>       Time   Temp F Dewp F  MPH   Direction    Dust  DIMM   Sky
>
>      23:05Z    67    33     19   262  (W)     3660     -    Mostly Cloudy
...
>      09:06Z    51    28     22   267  (W)     1917     -    Clear
So there was a ~16F (~9K) change in outside air temperature between afternoon
and the out-of-spec spectro focus (though possibly more in the enclosure - it
was hot and sunny during the day).  This is similar to other nights at this
time of year (see the one-week temperature plot near the bottom of
http://users.apo.nmsu.edu/sky/weather/latestweather.html).
It continues to be of concern that it's only SP1 that goes out of spec.
--Pete