Erroneous Pointing

Monday, May 6, 2013 1:18 PM

Problem(s) Encountered:

We set up the instrument and got some calibrations but were unable to take any science images. We think the pointing might be off but we reset the pointing from the zenith and that did not help. We were not able to find any of our science images.


Solutions:

With the tilt sensors at their nominal values for zenith, HA was at ~1sec but declination showed +31 54 12.  Tried to set the encoders to zero the errors (+31 57 12) but the declination value did not change (RA changed as expected).  Tried setting the declination readout to various values and found that it came out consistently 4 minutes south of the demanded position.  This could obviously cause issues with moving target-to-target.  Powered down TCS software/hardware and restarted.  This appeared to correct the issue (perhaps the epoch was not reading out correctly?).  Just spoke with the observer (21.00 LT) and was informed that pointing looked good so far.