Millimeter wave reflectivity of sea ice

The physical nature of the sea ice surface is discussed with respect to small-scale roughness. The dielectric properties of sea ice at 34 GHz are presented. Results of in situ reflectivity are presented. Interest in the Arctic Ocean in recent years has produced the need for new and better methods of transport through and over its ice cover. To facilitate routing of ice breakers and surface effect vehicles, better ice navigation systems and methods of determining ice surface topography are needed. One area of major emphasis is in the development of radar systems which produce an image of the ice surface, both for large area surveillance, as in the case of airborne side-looking radars, and for navigational radars carried by the vessels themselves. Because of the detail of the surface and the guidance information needed high degrees of resolution are desired, requiring the use of systems operating at frequencies in excess of 20 GHz. To aid in design of such systems, some fundamental information about sea ice as a millimeter wave reflector has been obtained.