Quality control systems for the Very Large Telescope

The operational applications needed to quantitatively assess VLT calibration and science data are provided by the VLT Quality Control system (QC). In the Data Flow observation life-cycle, QC relates data pipeline processing and observation preparation. It allows the ESO Quality Control Scientists of the Data Flow Operations group to populate and maintain the pipeline calibration database, to measure and verify the quality of observations, and to follow instrument trends. The QC system also includes models allowing users to predict instrument performance, and the Exposure Time Calculators are probably the QC applications most visible to the astronomical community. The Quality Control system is designed to cope with the large data volumes of the VLT, the geographical distribution of data handling, and the parallelism of observations executed on the different unit telescopes and instruments.