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VIRCAM pipeline:
general information

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general info
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general VIRCAM


This page provides information about pipeline processing and data types.

Raw data are selected, associated and inserted into a reduction mechanism which produces calibration products, science products and quality control information. This mechanism is the data processing pipeline. There is one such pipeline for each VLT and VLTI instrument.

Find general information about ESO reduction pipelines here.


The main functionalities of the pipelines are:

  • create master calibration data,
  • reduce science frames,
  • extract QC information from the data.

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.

Before October 2011 QC Garching processed science data, using the best available, quality-checked master calibration data. As of October 2011 this service is not offered anymore.


There are two instances of the data reduction pipelines:

  • at the instrument workstation on Paranal, running in automatic mode,
  • at HQ Garching, run by the Quality Control Group in the optimized mode.

The automatic mode is used for quick look purposes 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.

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 checked.

VIRCAM pipeline

The VIRCAM data processing pipeline is operational since Oct 2009 (ESO observing period 84).

The VIRCAM pipeline is not publicly available. Details on the VISTA pipeline can be found at CASU.


VIRCAM calibrations are acquired and reduced according the VIRCAM calibration plan. The calibration cascade is illustrated in the next figure.


The only observing mode of VIRCAM is : IMAGING

The pipeline supports all types of calibrations of the calibration plan. There is also a science recipe which reduces science images on the paw print level.


Raw data. The detector head of VIRCAM is equipped with 16 Raytheon VIRGO 2048 x 2028 pixel detectors. VIRCAM raw frames come as fits frames with one primary header and 16 extensions, each one consisting of an header containing detector specific information and pixel data.

Products. Pipeline products have can have two formats:

  • Fits frame with one primary header and 16 extensions each one consisting of an extension header and pixel data.
  • Fits file with one primary header and 16 extensions each one consisting of an extension header and a binary table