ATCA Observing Characteristics Calculator
This page provides a means of estimating the characteristics of
an ATCA observation. This includes the theoretical RMS noise in
an resultant image (Stokes I, Q, U, or V). The corresponding brightness
temperature sensitivity is also calculated. These estimates are based
on the expressions appearing in the ATNF technical document
AT/01.17/025, the latest calculations of antenna efficiency as a
function of frequency, the latest measurements of system temperature
as a function of frequency, and simulations of the effects of
different weighting schemes on images made with different ATCA
configurations.
In calculating the effects
of weighting, 30 second samples and Miriad default cell and image
sizes were assumed. It is also assumed that the central 81.25% of the
bandwidth is used for continuum imaging, corresponding to using the
birdie option in Miriad task atlod.
It is assumed that the nominated integration time is
evenly spread over a 12 hour observation.
Note the time given is the integration time: this does not account
for overheads involved in calibration. Depending on the
calibration scheme used, these overheads might vary between 5% for simple
20cm observations, to 50% for 3mm observations.
Page last updated: 13-Jun-2007.
This tool was originally developed by Steven Tingay and Lister Staveley-Smith, and developed further by Bob Sault.