Efficient wide-field VLBI imaging

Talk at a meeting of the LOFAR long baselines working group, 20 May 2009

O. Wucknitz [1]

  1. Argelander-Institut für Astronomie, Auf dem Hügel 71, 53121 Bonn, Germany

Abstract

I present results from our wide-field VLBI experiment at 90cm wavelength in which we mapped regions of interest around known WENSS sources within the primary beam of the telescopes. In order to image the complete primary beam, more efficient methods are required. These are now being worked out. I present how the complete primary beam of any VLBI observation with sufficient resolution in time and frequency can be mapped with moderate effort using a hierarchical down-averaging approach. This is faster than classical methods by several orders of magnitude.
A brief discussion of w-projection is also included.
Even though my new method was developed for VLBI, it may also be of use for wide-field mapping with the international LOFAR. The gain is less than for VLBI, but any improvement in efficiency is even more urgently needed.



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Script last modified on 7 Sep 2010
Last change to this data base entry on 25 May 2009