In this subproject a review of all aspects of ``quality'' and how certain performance factors impinge on the ``quality'' of the final products has been performed. It was recognized that there are different factors that have bearing on performance. There are, for instance, static factors that relate to permanent conditions. These can be global, and relate to the fundamental technique (deficiencies in choice of operating frequency, i.e. attenuation, etc.), and/or they can relate to the particular installation (local interference, both physical and electrical, and the particular hardware employed). There are also changing factors that relate to variable performance of the equipment and the ability of the technique to cope with changes in the environment that it is trying to sample. These can be long-term trend type changes or very rapid dynamic changes.
I Holleman, G Galli, B Urban, D Michelson. Definition of Product Quality Descriptors
2002, EUMETNET OPERA, 2002