Deparment of Astronomy: Kemball Research Group

Square Kilometer Array Technology Development Project (TDP): Calibration and Processing Group (CPG)

US participation in the international SKA program is via the US SKA Consortium, a community collaboration of US universities, institutions, and national centers who are collectively working toward achieving the goals of the SKA program.

The National Science Foundation has funded a US Technology Development Project (TDP) for the Large-N/Small-Diameter (LNSD) SKA Concept (NSF 0431486) for the period Oct 2007 to Sep 2011, under the leadership of Professor J. Cordes of Cornell University. The TDP Calibration and Processing Group (CPG) is an integral part of the TDP.

Calibration and processing is recognized by the SKA program as a substantial area of design risk and project cost. Many calibration and processing issues required for the SKA represent substantial advances over current state-of-practice at existing radio interferometers. Data rates and computational demands for LNSD SKA designs are unsolved petascale problems, as are the associated imaging fidelity goals. Research in these areas strengthens the TDP by developing a comprehensive case for achieving SKA science goals with a reference LNSD design. No plausible SKA construction proposal for either Phase 1 or the full SKA is possible without answering feasibility and cost equation questions concerning calibration and processing. These issues play a particularly important role in the SKA project as a result of the science need for large field-of-view and high sensitivity, and various considerations that drive digitization much closer to the receptors in contemporary radio interferometer designs, making calibration and processing costs an increasingly dominant design and cost driver. It is also important for the US to maintain engagement in this important area of the international SKA program. It is expected that calibration and processing costs will be large enough to influence the overall cost optimization and thus will influence both the diameter, D, and number of antennas, N, in LNSD designs, and, hence, the range of antenna design solutions pursued.

With a special focus on problems related to the LNSD parabolic antenna SKA design, single-pixel feeds, and the mid- to high-range SKA frequencies, the overall goals of the CPG are to:

  • Determine the feasibility of calibration and processing required to meet the SKA science goals (e.g. dynamic range, calibration and imaging feasibility).
  • Determine the quantitative cost equation contributions and design drivers arising from calibration and processing, as a function of key design parameters (e.g. antenna diameter, mount type, frequency, instantaneous and multiple field-of-view, array geometry, bandwidth and spectral resolution, amongst other factors).
  • To measure algorithm cost and feasibility using prototype implementations of new or existing calibration and processing algorithms.
  • To demonstrate calibration and processing solutions using pathfinder data.