RELATIONSHIP BETWEEN ERS-1 SAR SIGNATURES AND ARCTIC SEA ICE PROPERTIES DURING SPRING

 
  Robert G. Onstott and Robert A. Shuchman
  Earth Science Group
  Environmental Research Institute of Michigan
  PO Box 134001, Ann Arbor, Michigan, USA, 48113-4001
  Phone: (313)994-1200 FAX:(313)994-5824 Mail: Onstott@ERIM.org

  Studies have been conducted to associate ERS-1 SAR signatures with ice
  form and state to  examine  inter-regional, regional, and temporal
  signature variation. Of  particular interest, is the accuracy of the
  retrieval of ice type, deformation state, thickness, and physical
  property information.  We have conducted five in situ campaigns since
  1992 during which SAR products and ice physical property data have been
  collected in support of the study of the microwave science of sea ice.
  In this paper, the final results of a March-April campaign to study the
  air-ice-sea interaction in association with recently formed leads in the
  Beaufort Sea will be presented.  An ice camp was established and manned
  for a five-week period at a location about 200 nm north of Pruhdoe Bay,
  Alaska.  SAR observations were used to monitor ice conditions in this
  region, and to track floes from the start of the growing season until
  summer melt.  During this investigation, in situ information was gathered
  for thick first year ice of two prominent thickness categories (e.g. 1.3
  and 2 m), multiyear ice, lead ice, and deformed ice.  This included in
  situ microwave scattering measurements to complement the signature
  information obtained by the ERS-1 SAR and to extend it by obtaining a
  full angular (e.g. 0 to 70 degrees) and polarization (e.g. VV, VH, HV,
  HH) response.  Detailed characterization measurements were made of the
  profile properties of the ice sheets.  Vertical height statistics of
  level surfaces were also measured.  Surveys were made of the deformation
  features of various scales.  Features include titled blocks, ridge lines,
  pressure ridges, rubble fields, and  massive hummocks (e.g. pile of
  blocks to heights up to 15 meters).

  Topics which will be emphasized include:

  z association of SAR backscatter intensity with rms vertical height for
  deformed first year and multiyear ice,

  z relationship between SAR backscatter intensity, ice thickness, and ice
  profile properties for medium and thick first year ice,

  z relationship between SAR backscatter intensity and ice forms within
  dynamic leads, and

  z temporal signatures of first year and multiyear ice during the entire
  growing season based on the floe tracking results.

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry