Data Set Overview
  =================
  This data set is intended to include all published groundbased asteroid
  radar detections through April 2012.  These entries were extracted from the
  compilation of published and unpublished asteroid radar detections,
  established by Steven J. Ostro and currently maintained by Lance A.M. Benner
  at http://echo.jpl.nasa.gov.  Disc-integrated radar properties have been
  collected from the published papers and added to the file by Carol Neese.
 
  Modification History
  ====================
  The radar data set was first introduced into PDS at the April 1994 asteroid
  data sets review, and has been updated yearly since that time.  Updates
  consist in adding entries for asteroid radar detections published since the
  previous update.  The 1997 update added radar albedos, and these have
  continued to be added in subsequent updates.  Prior to version 10.0, the
  data set included unpublished detections.  Starting with version 10.0, only
  published detections are included.
 
  Parameters
  ==========
  An entry for each detection reports radar cross-section, circular
  polarization ratio and radar albedo, if known, error values for  these
  parameters, year of observation, and the reference in which  the
  observations were reported.  There is also a flag indicating whether a shape
  model is reported.
 
  Ancillary Data
  ==============
  The references of the papers in which the asteroid radar detections were
  reported are compiled in the file 'radarref.tab'.  For a complete list
  including unpublished asteroid detections, see the file
  'astradarhist0111.htm' in the document directory.

Confidence Level Overview
  =========================
  The confidence level of each data value reported is reflected in the
  uncertainty value in the same entry.  Further information about the
  observations can be obtained by consulting the original reference for each
  entry.
 
  Data Coverage and Quality
  =========================
  This data set is intended to include all published groundbased radar
  detections of asteroids.  It is complete through April 2012.  If an item of
  data is missing from the table (appearing as a null value such as 9.99),
  this indicates that the data item is not available from the published paper.
  For example, for monostatic radar observations, circular polarization ratio
  cannot be derived, so it is left blank.  In some cases, the data provided in
  the paper are too complex to be presented in the table, as in the case of a
  time-series of values.  In case of questions, the original papers should be
  consulted.