SKA South Africa: Activities and Simulation Questions

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SKA South Africa Activities and
SimulationQuestions

• Jasper Horrell
• Saratoga Software

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• Government Backing for Astronomy
• Funding from NRF
• Seen as high tech new industries, etc. Build
  local capacity.
• Promotes local and international collaboration.
  Academic and industry involvement.
• Projects to inspire nations young scientists and
  engineers
• Successful projects and facilities SALT,
  Sutherland, HARTRAO, HESS,
• SKA

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• SKA Related Activities
• Site bid
• SA Pathfinder Instrument
• HPC
• Involvement in global SKA effort working
  groups, etc.

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• SKA Simulation and Site Planning
• Early days. Getting up to speed with existing
  software etc. Immediate focus to be mostly in
  support of site bid.
• Catherine Cress and Angel Rodriguez MAPS,
  AIPS
• George Nicolson array layouts
• Sheereen Rawat - GIS

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• Catherine Simulation Detail
• Used the MAPS array module to generate antenna
  positions.
• Tried various simulation tasks in MIRIAD and
  AIPS, inputting FITS images of potential targets
  and looking at the images the telescope would
  produce given various layouts and parameter
  settings.
• Thinking about simulating the "input" images ...
  so far simple things like taking 21cm images of
  nearby galaxies and figuring out what they would
  look like at much larger distances but we're also
  thinking about applications of large-scale
  structure observations to cosmology.
• Goodness-of-fit (U-V coverage stats) The
  process you outlined is nice simple .. I'm
  going to think about it a bit more and get back
  to you

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• RFP Discrepancy? comment from George
• The configuration requirements in the RFP are
  consistent but for one point. The RFP specifies
  that one half of the remote stations should lie
  within 150 km from the core, whereas SKA Memo 45
  states within 150 km diameter. The remaining
  stations should then be distributed out to at
  least 3000 km.
• It is clear that the figure in Memo 45 is correct
  for a logarithmic distribution. This is also
  consistent with the definition of the RQZ which
  is also 150 km in diameter, so that 75 of the
  array will lie within the RQZ.

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• Array Layout Simulation Issues
• Short Timescales layout in 2 months
• Avoid weakening site proposal due to
  non-optimised layout
• Figures of merit beam shape, coverage, image
  fidelity, sidelobes, ?
• How to optimise?
• Reference array spiral, number of arms, core
  layout?
• Standard sky scene is this necessary?
• LNSD and LDSN layouts
• Software tools create new, easy access, local
  install with source
• Agreement on standard evaluation procedure and
  software
• Transparent process best layouts available for
  all to scrutiny?
• Approval for layouts?
• Amendments to RFP

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• Action Plan?
• Support Stevens action plan
• Lots of unknowns. Short timescales. Attempt to
  remove clutter from process. Reference array idea
  sounds a useful one.
• Need standard, open, process, endorsed by ISSC
• Need standard software
• Need array layout by end November 2004 !!