Observing descriptions and execution

Specifically for service observing the general description of observations, in the form of Observing blocks (OBs), and the execution of observations through (sequencer) scripts have up to now been handled by two different web forms. Beyond this we also have been and are developing more, and more extensive, sequencer observing scripts. The obvious thing to do is to integrate these to make the definition and execution of observations easier and more reliable.

One of the main problems in this is allowing for flexibility without making things too complex as this is counter to the idea of making it easier and more reliable. To avoid this we have decided to limit the definition of any OB to a single instrument $and$ observing mode (e.g., ALFOSC-imaging, NOTCam-spectroscopy, etc). For each of these combinations we now have defined which parameters need to be set and what the available options should be for each parameters. In this way we limit the number of parameters in each case (e.g., no slit or grism needs to be defined for imaging) and we can provide specific options in a limited number of input windows and pull-down windows. The next step will be to define how each parameter setting is ``translated'' to a specific (set of) sequencer command(s) or script(s). The final step would to provide an interface to define instrument+observing-mode specific OBs and an application that translates this to a complete sequencer script that combines all the commands and scripts that are defined by the parameters for execution.

The number of observatory supported sequencer scripts has been further expanded and are more and more used by observers. More complex and extensive scripts are also being developed by one of the groups that have a target-of-opportunity (ToO) program running at the telescope. Together with the further integration of our observing system and the above described developments the idea is that in the future the observer will need to run a script which will, as far as possible, execute the ToO observations automatically, and guide the observer through its execution and afterwards the return to the original observing set-up.

As part of allowing for full scripting of observations also all the (post-processing) procedures that process the data to allow its analysis as part of the observations (e.g., to define if the data are of sufficient quality, or to identify an object to be place in the slit for spectroscopic observations) are now fully integrated sequencer commands and scripts.

Thomas Augusteijn 2009-05-14