Accession Number:

AD0736593

Title:

Reflection of MM Waves from Snow and Sea Ice

Descriptive Note:

Semi-Annual technical rept. 1 Jun 1971-31 Jan 1972

Corporate Author:

ALASKA UNIV FAIRBANKS INST OF ARCTIC ENVIRONMENTAL ENGINEERING

Report Date:

1972-01-31

Pagination or Media Count:

109.0

Abstract:

The report relates to utility of imaging radars for arctic surface guidance. The program involves field measurements of backscatter from snow, ice and sea ice for a wide variety of meteorological and surface conditions. Laboratory measurements of the complex dielectric constant are presented also, to enable the separation of the roughness contribution to the backscatter. During the first seven months of the program, the dielectric properties of sea ice were measured in the laboratory from 36 to 40 GHz, over a representative range of temperatures, salinities, and orientation. The real part of the dielectric constant is close to 3 for most conditions, but the loss tangent can vary over three orders of magnitude, depending upon the temperature and salinity. Under most conditions, an incident wave of 1 cm wavelength would penetrate less than one meter into the sea ice. Strong distinction of freshly- formed sea ice from old sea ice appears likely. Backscatter from sea ice is currently being measured. Distinction of rough and smooth surfaces is possible, based upon preliminary interpretation of the data.

Subject Categories:

  • Snow, Ice and Permafrost
  • Active and Passive Radar Detection and Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE