Quality control of VLT NACO data

The Nasmyth Adaptive Optics System (NAOS) and the High-Resolution Near IR Camera (CONICA) are mounted at the Nasmyth B focus of Yepun (UT4) telescope of the ESO VLT. NACO (NAOS+CONICA) is an IR (1-5 micron) imager, spectrograph, coronograph and polarimeter which is fed by the NAOS - the first adaptive optics system installed on Paranal. NACO data products are pipeline-processed, and quality checked, by the Data Flow Operations Group in Garching. The calibration data are processed to create calibration products and to extract Quality Control (QC) parameters. These parameters provide health checks and monitor instrument's performance. They are stored in a database, compared to earlier data, trended over time and made available on the NACO QC web page that is updated daily. NACO is an evolving instrument where new observing modes are offered with every observing period. Naturally, the list of QC parameters that are monitored evolves as well. We present current QC parameters of NACO and discuss the general process of controlling data quality and monitoring instrument performance.