The most recent version of the ATCA Sensitivity Calculator is available here -- this version is retained for use with archival data.
This page provides a means of estimating the characteristics of ATCA observations with the Compact Array Broadband Backend (CABB) system. The calculator allows both available and planned CABB modes to be selected: please check the CABB webpage for which modes have been implemented. (The pre-CABB sensitivity calculator is still available and may be useful for those considering archival ATCA data.) The calculator 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 calculations of antenna efficiency as a function of frequency, revised (CABB era) 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. For CABB it is assumed that the full 2GHz is available at 4GHz and above, and that 500MHz is available at 20cm and 13cm. RFI may reduce the usable bandwidth, particularly at 20cm.
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. The most recent version of the ATCA Sensitivity Calculator is available here -- this version is retained for use with archival data.
Page last updated: 14-Nov-2009.
This tool was originally developed by Steven Tingay and Lister Staveley-Smith, and developed further by Bob Sault and Phil Edwards.