Astronomy below the Survey Threshold
  Astronomy at or below the 'survey threshold' has expanded significantly since
the publication of the original 'Science with the Square Kilometer Array' in
1999 and its update in 2004. The techniques in this regime may be broadly (but
far from exclusively) defined as 'confusion' or 'P(D)' analyses (analyses of
one-point statistics), and 'stacking', accounting for the flux-density
distribution of noise-limited images co-added at the positions of objects
detected/isolated in a different waveband. Here we discuss the relevant issues,
present some examples of recent analyses, and consider some of the consequences
for the design and use of surveys with the SKA and its pathfinders.
