Some Survey Speed Issues 1

1
Some Survey Speed Issues (1)

• SSFoM FoV (A/T)2
• Omits the bandwidth, detection limit, transient
  factors
• FoV is cheaper than A/T so have to consider
  tradeoffs
• HI emission
• FoV ? (A/T)2 OK up to max FoV
• Redshift is compensated by ?/D for SPF but not
  for PAF
• HI absorption
• Needs large FoV to get enough sources
• Needs high angular and frequency resolution
• CPU costs impossible
• But only need a well defined fraction of the FoV
  so use the summed array beams
• Currently 50 NEED INPUT

2
Some Survey Speed Issues (2)

• Continuum surveys
• FoV ? (A/T)2 OK up to max FoV
• But max FoV needed is modest (1sqd)
• Continuum surveys for rare objects
• May need very large FoV
• Steep spectra ( a lt-2) are the high z radio
  galaxies
• Circularly polarised sources
• High angular resolution (VLBI)
• Need summed array beams for sources at known
  locations
• Astrometry calibration

3
Time domain surveys

• Pulsars
• FoV ? (A/T)2 trade not possible in most cases
• Survey needs very compact core
• Data processing limited
• Consider the advantages of using summed array
  beams for the survey
• Forming an image with channels every µsec is a
  huge data expansion array beams
• How many summed array are needed
• SETI
• Summed array beams inside FoV
• How many targets ?
• Cosmic Rays
• Example of need for ?sec time resolution
• Large number of phased array beams