The QC group processes a stream of
science-grade data products for selected VLT instruments. They are created using certified pipelines and certified master calibrations.
Find an overview of the current streams here.
Science raw data are contaminated by well known instrumental signatures and by the atmosphere. Both effects are eliminated from science raw data by using master calibrations. The day-time calibrations like DARK, FLAT, WAVE are to extract the instrumental signatures while the night time calibrations using standard stars are to monitor the point spread function and the telluric absorption lines, both effects are due to the terrestrial atmosphere and are changing more frequently than the instrumental signatures.On special request by the user, day-time calibrations can be scheduled during night time, on charge of the allocated science observing time. nighttime (so-called attached calibrations). Day-time calibrations and the observation of telluric standard stars come for free. See the User's manual for details.
The different science templates are supported, they differ only by the pointing offset sequence (the jitter strategy). Science frames come as IFS stacks. Some or all raw frames of a raw stack (on observation block) show DPR.TYPE == OBJECT, the others (or none of the stack) show DPR.TYPE == SKY. If no SKY frames are part of the science stack, sky emission lines cannot be reduced. This is different to ISAAC long-slit spectroscopy, where the ABBA nodding sequence is used to get rid of the spectrally resolved night sky. As for ISAAC and NACO imaging , the SINFONI GenericOffset template allows for telescope offsets, exceeding a so-called jitter box. The correlation star retrieved from the first raw frame and used for the rest of the stack could get lost by being jittered out of the jitter box. For this reason, the rarely used science case of mosaicing is not supported by the pipeline.