Data Processing

by Stephan W. Witz last modified Apr 29, 2013 by Stephan Witz

The primary data reduction package for the VLA is the CASA (Common Astronomy Software Applications) package, which is also used for ALMA.  See http://casa.nrao.edu for more information on the latest release.

It is possible to reduce VLA data taken in all correlator modes that are offered for general observing using CASA.  More complex correlator set-ups are generally better handled by CASA, and advanced imaging algorithms are available in CASA.  The VLA calibration pipeline uses CASA.

The Astronomical Image Processing System (AIPS) can reduce all observations made with simple correlator set-ups (e.g., identical spw bandwidths and channel widths throughout).  AIPS is currently required for the reduction and analysis of phased-array VLA observations for VLBI and low-band observations (P-band, 230-470 MHz). NRAO will continue to support AIPS for the foreseeable future, at least until VLBI functionality and the full data path for frequencies below 500 MHz have been incorporated into CASA.  See http://www.aips.nrao.edu for more details.