This archive contains Earth-based, polarimetric radar image data for Venus
  collected from 1988 onwards, using the Arecibo Observatory 12.6-cm
  (2380 MHz) transmitter and receivers at either Arecibo or the Green Bank
  Telescope in West Virginia. One sense of circular polarization is
  transmitted, and both senses of the reflected echo are recorded in
  amplitude and phase. These data have a horizontal spatial resolution of
  1-2 km in the highest-resolution mode, and about 8 km in a
  lower-resolution mode used to increase the signal-to-noise performance for
  some polarimetric analyses. The first data products archived are
  complex-valued images of the backscatter from Venus for individual
  coherent looks five minutes in duration. Up to about thirty such looks for
  the north and south portions of the planet's disk visible at each inferior
  conjunction are collected. The maps are in un-calibrated, delay-Doppler
  format, and thus require additional processing to normalize the echoes to
  the background noise and convert the spatial sampling to a
  latitude-longitude format. Once those steps are completed, users may sum
  the images as they choose to create multi-look (reduced speckle, higher
  SNR) dual-polarization maps of the surface or Stokes-vector values for
  polarimetric studies. Future PDS releases may include such calibrated and
  summed maps produced by the data providers.

  Please see the document VENUS_RADAR.PDF in the DOCUMENT directory for
  further details, including information about the data collection and
  processing.

TBD.