Once the data has been acquired by an interferometer such as the NOrthern Extended Millimter Array (NOEMA) or ALMA, two different approaches may be used for its reduction and analysis:
The choice of clearly separating calibration and imaging+deconvolution was
taken at start of the Plateau de Bure Interferometer,
when the limiting number of antennas prevented
the use of self-calibration.
While many points of the calibration algorithms
inside red CLIC are specific to NOEMA data (in particular its range of
Signal-to-Noise ratio), the algorithms of imaging+deconvolution can be used
in many different contexts and the visualization and analysis of spectra
cubes is mainly independent of the instrument that delivered the data.
This last point implies that users can import data from ALMA (mainly through FITS format)
in [rgb]1,0,0IMAGER for imaging and deconvolution, and in red VIEWER for
visualization. But the reverse is also true. While calibration
of NOEMA data should be done inside red CLIC, imaging+deconvolution and
visualization+analysis can be done in other softwares (e.g.
With the improvement of NOEMA (increase of the number of antennas
and better receiver sensitivities) and with the advent of a new
generation of interferometer (ALMA), the additional step of
self-calibration may improve the consistency of the final results by
imposing additional consistent constraints on the calibration. This
self-calibration step is further presented in Section
miriad ,
AIPS, CASA for the imaging and deconvolution
and KARMA for the visualization and analysis).
.