PIPELINES AT ESO
Pipelines are used at ESO to process both calibration data and science data
and to retrieve quality information.
There is a dedicated
pipeline for each VLT and VLTI instrument.
Find general information about ESO reduction pipelines here.
The main functionalities of the pipelines are:
QC Garching creates master calibration data from all raw calibration data. The
raw data are stored in the ESO Archive and are public. They are
quality-checked and used for data reduction and for trending.
- create master calibration data,
- reduce science frames,
- extract QC information from the data.
For selected instrument modes, we offer science-grade data products processed
with the pipelines.
There are two instances of the data reduction pipelines:
The automatic mode is used for quick look and for on-site quality
control. It processes all raw data sequentially, as they arrive from the
instrument. If calibration products ("master calibrations") are required for
processing science data, these are taken from a database with standard,
pre-manufactured calibration products. The automatic mode is not tuned to
obtain the best possible results.
- at the instrument workstation on Paranal, running in automatic mode,
- at HQ Garching, run by the Quality Control Group in the optimized mode.
The optimized mode is the mode, which uses all data of a night, including the
daytime calibrations. The calibration data are sorted and grouped according to
their dependencies. Master calibration data are created. Their quality is
The FORS pipeline is publicly available. It (since 2008-09-17) supports the reduction of imaging and spectroscopic data (LSS , MOS, and MXU mode). However, the HIT mode data are not supported.
Since 2015-04-22 new, significantly modified FORS2 pipeline version v.5 has been adopted. Master calibrations created by previous pipeline versions are not compatible any more and the pipeline requires modified static calibrations.
CALIBRATION and SCIENCE data
Find the description of FORS2 data processing and pipeline recipes for
calibrations here and for
science data here.
During the FORS2 detector upgrade on March 22, 2002, the old CCD has been replaced by a mosaic of two red/IR-optimized CCDs. The upper CCD is referenced as Chip1 (also called master), while the lower CCD is referenced as Chip2 (also called slave). Each FORS2 exposure is
split into two files, one for each CCD. The CCD mosaic is mounted off-axis so that the target falls by default on Chip1 and gap between the two CCDs falls between two MOS slits.
The raw FORS2 files in the standard CCD format (2x2 binning, no windowing) have 2048x1034 pixels. The field of view is limited by the MOS unit, therefore the field of Chip1 is larger than that of Chip2.
Two pre/overscan regions are present in the CCD. For the standard CCD format (2x2 binning), these regions are 5 pixels wide (i.e. rows 1...5 for the prescan and 1030...1034 for the overscan).
Graphical description of the detector sections:
Note that for presentation reason, the pre-scan regions have been artificially enlarged.