Echelle CCD Readout Weirdness
Monday, September 2, 2019 1:42 PM
I started to get going at 10:30 pm with flats and HgNe comparison exposures, but then had trouble with Echelle. At first, the frames read out as biases, similar to the problem Eric encountered on Thursday. We cycled the power, both on Owl and on the instrument, and it eventually began reading out, but then had these problems:
(1) flats had an abnormally high level in the blue
(2) flats had wavy noise pattern at times
(3) HgNe had weird noise pattern, and also looked like a flat+Ne (vertical stripe pattern like a flat).
Eventually, it seemed to go back to normal. We lost a less than an hour to this, and I started taking science data at 11:30 pm, and had no problems since.
There is certainly something odd with the readout, or electronics in general, for Echelle. With ARC now MIA, alternatives will be explored for how to detail Echelle and get it back to full functionality. Fortunately, it always seems to just fix itself when given the time. Not satisfying though.