Quality Control and
Data Processing

General information

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.

FUNCTIONALITIES

The main functionalities of the pipelines are:

• 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.

OPERATIONS

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 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.

Raw Data

The ESPRESSO detector consists of two e2v CCDs, each with 9216x9232 optically active pixels.

file type	binning	size of raw file
calibration or science frame	1x1	352 MB
calibration or science frame	2x1	176 MB
calibration or science frame	4x2	44 MB
calibration or science frame	8x4	11 MB

Extensions

Raw calibration and science data come as FITS files with one primary header unit (HDU) and at least two extensions, one for each chip. The primary HDU has all keywords necessary to identify the observation and the state of the telescope and the instrument; the data part is empty. Pixel data are stored in the extensions.

Observations of standard stars and of science targets have additional extensions which contain data from the exposure meter (as binary table) and integrated images of the fibre heads. The size of these extensions is negligible compared to the first two extensions.