MDM Observatory 1.3m Telescope Observing Report for 2011 Aug 27

Observer(s): Jules Halpern
Institution(s): Columbia U.

Instrument: R4K

Worked for 3 hours (last half of the night)
Conditions were Overcast most of the night.
No equipment or software problems were encountered.

Seeing and Weather:
   Beg: Overcast, Winds Light & Variable
   Mid: Overcast, Winds Moderate
   End: Seeing 1.3 arcsec, Patchy Clouds, Winds Moderate

Observing Summary:

The weather was not suitable for science observations, and I
couldn't even open until 2:30.  So I did some tests of the
guiding, imaging, and tracking.  This afternoon Dick Treffers
working remotely found, using some nifty software, that the
tracking servo motor was inducing a periodic component at
1.8 Hz. This was probably getting amplified to produce the
double images that I had seen.  He increased the frequency.
Tonight, there was no evidence of double images at the same
telescope positions that I used last night.  This seems
promising as a fix, although I would like to reserve conclusion
until we get a couple of more active nights.

I also worked on optimizing the tracking rates so that the
guider has to do as little as possible.  I'm not quite finished
with that because it also needs a small declination rate.

I investigated the effect of the guide rate (paddle gain)
on the quality of the guiding, but it didn't seem to make
much difference, which I suppose is good.  Actually, this
should be tested again when it is not so cloudy so the
guider can get a constant star signal.  I have a question
about how the Maxim DL autoguider software, together with the
TCS, is supposed to make the cos(dec) correction to the guide
rate (the Scope dec field in the guider window).  I sent this
in a separate message to John.

An acrobatic but stupid mouse got into the wastepaper basket,
and there is a large bee in here as well.  I'd give them about
equal long-term prospects.

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Submitted on 2011 Aug 28 [6:14:28]