Microwave/optical Studies of Saline Ice, Snow, Melt Ponds and Refrozen Melt Pond Ice
View/ Open
Date
1993-03Author
Gibbs, D.
Betty, C.
Fung, Adrian K.
Gogineni, Sivaprasad P.
Bredow, Jonathan W.
Metadata
Show full item recordAbstract
Optical and microwave measurements of a
variety of ice and snow targets were obtained in a
large indoor cold room at the U.S. Army Cold
Regions Research and Engineering Laboratory
(CRREL) in Hanover, N.H. Bistatic measurements
performed in the plane of incidence were obtained at
632.8 nm and backscatter measurements as a
function of incidence angle were obtained at 13.6
GHz. The 632.8 instrument that was used is a
portable version of the UTA Automated
Bidirectional Reflectance Acquisition Measurement
System (ABRAMS) and the University of Kansas 13
GHz instrument is a step frequency radar that is
based around the HP8753 network analyzer. In this
report we will consider the scattering behavior of
thermally modified saline ice, snow, melt ponds and
refrozen melt pond ice. Preliminary results indicate
that air bubbles in saline ice and melt pond ice are
important sources of scattering at optical
wavelengths. Microwave frequencies, on the other
hand, are sensitive to brine inclusions in the ice and
to liquid water at the ice surface; microwave
measurements showed a dramatic (8 dB) decrease in
nadir backscattering as a quiescent melt pond
refroze. Other topics that will be included in this
report deal with system calibration, and the use of
polarization in the plane of incidence to distinguish
between volume and surface scattering.