FITS keywords

As a more continuous task we have been working on improving the FITS keyword information provided in the observing data. As a general objective the keywords should provide a complete and unique description of the data in the FITS file. The current set of FITS keywords still not complete and there are a few things which are not, or not correctly defined. We have now started a project to define and implement a full set of keywords which should be complete in the sense that it will cover all the possible relevant parameters for the current `observing system' (telescope, instrument, detector) set-up. A specific set of keywords are those defining the type of any observation (referring to category [science, calib, test, etc], type [object, std, sky, flat, lamp, etc], and [observing] technique (image, spectrum, echelle, polarimetry, etc). For all of the different types of observations the (combination of) values for the 3 `observing type' keywords have been defined. The latter is strongly linked to the OB system that will be involved in setting these keywords, and to the data acquisition and archiving system that will use this information.

Thomas Augusteijn 2012-02-21