Observing system

A new script alfocs.alfosc-calibs was made that takes biases frames and spectral calibration frames for all instrument set-ups and CCD window settings used in a particular night. Per setup, the script takes 11 biases, 5 spectral flats, and 1 arc for each arc lamp. In principle the script is intended to be run at the end of an observing night. It can be run at any time for any night, but likely the instrument set-up will have changed. The instrument set-up is checked for inconsistencies in the current set-up versus the set-up used during the night. Any such inconsistent set-ups will be skipped, with a warning on the Talker.

Various updates were made to the instrument control software, improving error messages, warnings, time-outs, and status reporting of some of the ALFOSC/FASU mechanisms. Also, various minor updates/fixes were made to sequencer scripts, some of this being streamlining efforts to cut down on overheads.

To optimise a fast-photometry mode using the new CCD controller and data acquisition system we will define how we can provide time-series observations with minimal overheads to effectively replace the fast-photometry mode available with the old detector controller. As part of this, a review will be made of the different commands involved in observing to see if some of the delays can be made smaller to limit the overall delays as much as possible.

A system will be implemented in the data acquisition system that allows the requested exposure time to be corrected for relative delays between opening and closing the shutter. This will include a full set of image keywords that describe all the timing parameters (requested exposure, applied correction, etc).

Thomas Augusteijn 2013-05-10