Airborne measurements of forest and agricultural land surface emissivity at millimeter wavelengths

Author

Hewison, Tim J.

Author_Institution

Meteorol. Office, Hants, UK

Volume

39

Issue

2

fYear

2001

fDate

2/1/2001 12:00:00 AM

Firstpage

393

Lastpage

400

Abstract

Passive microwave radiometers have been operated on an aircraft over the an area of Sweden, near Uppsala in September 1995 and March 1997 as part of the Northern Processes Experiment (NOPEX). Their measurements have allowed the calculation of the emissivity of boreal forest and agricultural land surfaces at 24, 50, 89, and 157 GHz over a range of incidence angles and polarizations. These results show consistent differences between dense forestry, where the emissivity is close to 1 and open land, where it is approximately 0.96. These differences are examined and a model is presented to parameterize these surfaces by use of a Debye-like effective permittivity and Fresnel´s reflection coefficients. This will allow retrievals of atmospheric temperature and humidity profiles to be made by satellite microwave sounders, such as the advanced microwave sounding unit (AMSU) over similar land surfaces

Keywords

forestry; geophysical techniques; radiometry; terrain mapping; vegetation mapping; 24 to 157 GHz; AD 1995; AD 1997; Debye-like effective permittivity; EHF; Fresnel´s reflection coefficients; NOPEX; Northern Processes Experiment; SHF; Sweden; Uppsala; agriculture; boreal forest; emissivity; forest; forestry; geophysical measurement technique; incidence angle; land surface; microwave radiometry; millimeter wavelength; mm wave; polarization; remote sensing; terrain mapping; vegetation mapping; Aircraft; Atmospheric modeling; Forestry; Fresnel reflection; Humidity; Land surface; Land surface temperature; Permittivity; Polarization; Radiometers;

fLanguage

English

Journal_Title

Geoscience and Remote Sensing, IEEE Transactions on

Publisher

ieee

ISSN

0196-2892

Type

jour

DOI

10.1109/36.905247

Filename

905247