A Study of the Microwave Brightness Temperature of Sea Ice.

• Main Author: Stogryn, A
• Other Authors: AEROJET ELECTROSYSTEMS CO AZUSA CA
• Format: Text
• Language: English
• Published: 1986
• Subjects: Snow; Ice and Permafrost; Active & Passive Radar Detection & Equipment; *MICROWAVES; *DIELECTRIC PROPERTIES; *BRIGHTNESS; *ANISOTROPY; *SEA ICE; *BRINES; TEMPERATURE; PARAMETERS; THEORY; VARIATIONS; PURITY; ICE; CONSTANTS; ISOTROPISM; TANGENTS; LOSSES; EQUATIONS; ISOTHERMS; ELECTROMAGNETIC SPECTRA; Ice; permafrost; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/ADA178271; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA178271

The work reported here, considers the computation of the microwave brightness temperatures of various types of sea ice. The methodology is an application of theoretical and experimental results obtained at Aerojet ElectroSystems Company under previous contracts with the Office of Naval Research. In these studies, the bilocal approximation of strong fluctuation theory was used to develop equations for the effective dielectric constant of both isotropic and anisotropic random media as well as equations for calculating the brightness temperature of isothermal isotropic media. The earlier work also examined the present state of knowledge concerning the dielectric properties of the constituents of sea ice. It was found that there were significant uncertainties relating to the loss tangent of pure ice as well as the dielectric properties of brine in sea ice. The latter problem was overcome by a systematic measurement of the dielectric properties of brine and the derivation of Debye parameters which allow the dielectric constant of brine to be calculated throughout the microwave portion of the electromagnetic spectrum. The uncertainties with respect to the loss tangent of pure ice remain so that a tentative model based on available experimental data must be used.