Poster Abstract

P.20 Des Small (JIVE)

VLBI data processing with CASA

The CASA software package is the de facto standard for the reduction of
radio data from connected-element interferometers, but until recently
it did not have all the features needed for Very-Long Baseline
Interferometry (VLBI) data reduction, where an array of
widely-separated antennas -- sometimes on a global scale -- observe
together through different atmospheric conditions using separate
clocks.

In the last few years an effort lead by JIVE has added the new
functionality necessary for VLBI data processing to CASA. With the
current release, tasks for fringe fitting and amplitude calibration
based on auto correlations are included and the package is now capable
of end-to-end processing of VLBI data, while work is ongoing on novel
methods for dispersive delays and wide-band data, with applicability from
LOFAR long-baseline observations, the next generation of antenna
receivers and the forthcoming SKA

In this oral presentation we will describe these features, and show
some results from a variety of VLBI arrays produced using the new CASA
tools, including their use as part of the data reduction process for
the recent EHT image of a black hole shadow.