ALMA Memo # 430

Compact Configuration Evaluation - Mosaicing

Melvyn Wright Radio, Astronomy laboratory, University of California, Berkeley 

22/07/2002

Keywords: Antenna Configurations, Image Simulations, Mosaicing 

Abstract 
In this memo, we compare the mosaicing performance of compact
configurations.  MIRIAD scripts simulate mosaic observations with ALMA,
calculate error images and pipeline the results into tables.  The
residual imaging errors are characterized by the recovered flux, peak
flux density and the sidelobe levels.  We present tables of the
sidelobe levels and image fidelity for source declinations from +60 to
-60 degrees.  Mosaic images for source diameters 24 and 32 arcsec
are analyzed.  For the 24'' source, a Gaussian configuration provides
the best image fidelity.  For the 32'' source, the most compact
configuration provides better sampling of the large scale structure and
better image fidelity, except at high declinations where the array is
strongly shadowed.