Status Report from Cincinnati, July 2002

Mike Gutzwiller
July 10, 2002

It's been a while since I published a report on progress in Cincinnati so here goes.

The main effort here in Cincinnati has been on four fronts:

  1. writing the control program,
  2. alignment, calibration and operations development,
  3. development of an observation plan and
  4. analysis of engineering data.

The control program at this point fits my needs though there are several improvements that could be made. Most notably lacking is the ability to control the focus motors. I don't need that right now since the cameras are pretty well focused as it is.

The camera is better aligned now. I can still improve it though. The RA drift is about 0.27 degrees over two hours. It is linear so I should be able to adjust it by setting the VCO DAC value. The equatorial axis seems to be off 0.6 degrees (if my calculations are correct). I should be able to adjust this with some small shims. I have been able to eliminate ice crystals in the V camera by running dry air through the camera about an hour before taking images.

My first observation plan is to look at the celestial equator and follow in RA for 2 hours. I also plan to center the image (at least at first) on RA values which are multiples of 30 degrees. This way I can generate multiple nights worth of data on certain regions of the sky instead of starting at a random RA value each night. Concentrating on the celestial equator will allow me to use multiple Landolt standards for color calibration later. I still need a viable plan for generating flats. Right now I'm thinking of automatically generating twilight flats at the end of each observing session but I don't know if there will be enough time to generate a good set of flats. Right now I'm creating 2 minute exposures every 3 minutes.

I have been looking at the data I've generated so far and am also getting a base of about 0.01 magnitudes sigma for bright stars. I'm using my own pipeline based on the code used for the Mark III data analysis.