A complete set of calibrations consists of day-time calibrations (darks,
biases, flats, optical distortion) and optional user defined on-the
sky calibrations (e.g. PSF standard stars,
telluric standard star.). The science template allows for science frames
(tagged DPR.TYPE=OBJECT) and for OB-specific calibrations which are
tagged SKY, OBJECT,CENTER and OBJECT,FLUX. All day-time, night time
and OB-specific calibrations need to be processed in a certain order,
that the products of a previously processing step are available for
following steps in the calibration cascade. The SPHERE calibration scheme
is composed of eight independent calibration cascades, for each mode one.
A graphical representation of all eight SPHERE calibration cascades can be found
here.
Within the data reduction cascade, a subset of calibration types
is supported by the data reduction pipeline. The supported
calibration types generate product of which a subset contain
quality control parameters useful to monitor the health of the three arms.