The Detector Monitoring Project

Many detectors, optical CCDs and IR arrays, are currently in operation onboard ESO instruments at the La Silla Paranal Observatory. A unified scheme for optical detector characterization has been adopted since several years in La Silla, and it is used by the Science Operation team to monitor the IS CCDs belonging to the eight instruments operated by ESO at the Observatory. This scheme has been proven successful in ensuring a high quality performance of the detectors along the years. In Paranal the science operation team and QC Garching monitor the performance of the detectors using instrument-specific data reduction pipelines. Understanding the performance limits and the calibration requirements of an instrument is fundamental in the operational scheme followed at the observatory and crucially depends on our knowledge of the nature of the detector arrays, their key performance parameters and the way these are defined and measured. Recently two issues were addressed: (1) despite the many commonalities among detectors, different ways to check their performance are in use and (2) the characterization matrix is often incomplete, i.e. not all crucial parameters are measured for all detector systems. The detector monitoring project arises from the desire to improve the efficiency of the data How, simplify Quality Control (QC) operations and promote standardization of testing procedures among detectors in use at ESO. The goals of the project are: (a) designing a detector monitoring plan that covers all the detectors in use; (b) reviewing the current reduction procedures and associated pipeline recipes; (c) standardizing the test procedures whenever applicable; (d) merging the test. procedures for IR and optical detectors when possible and describe the differences in all the other cases; (e) consolidate the measurement procedures and the use, of data reduction recipe and algorithms. The ultimate goal is to provide the observatory and the instrument operation teams (IOTs) with a complete and homogeneous detector-monitoring scheme.