Microwave Emission from Polar Surfaces.

• Main Author: Grenfell, Thomas C.
• Other Authors: WASHINGTON UNIV SEATTLE DEPT OF ATMOSPHERIC SCIENCES
• Format: Text
• Language: English
• Published: 1998
• Subjects: Radiofrequency Wave Propagation; Geography; *MICROWAVES; *POLAR CAP; ALGORITHMS; EMISSION; PHYSICAL PROPERTIES; PASSIVE SYSTEMS; RADIATIVE TRANSFER; SURFACES; MICROWAVE FREQUENCY; EMISSIVITY; Ari; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/ADA343249; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA343249

Based on the work described in this report, our observations and modeling work have revealed several considerations which are central to understanding the physical basis for the application and interpretation of thin ice algorithms for passive microwave imagery. We have shown that passive microwave measurements provide one of the most robust remote sensing techniques for distinguishing among sea ice types including the thin ice types that are pivotal for regional energy considerations. We have found that current theories applicable at microwave frequencies (multi layer SFT wave theory, for example) and in the visible and infrared (radiative transfer theory) can reproduce the radiation signatures of FY ice types quite well incorporating the actual physical structure of the ice. As a result of the cooperative work carried out during the electromagnetics ARI, the determination of the wavelength regions and physical situations appropriate for the application of various radiation models has been improved considerably, and our results, both theoretical and observational, have demonstrate the levels of accuracy of the models. It is clear that our understanding of the microwave emissivities of sea ice and their relation to other types of remote sensing signatures has increased significantly in the course of this grant.