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The Study Of Fresh-Water Lake Ice Using Multiplexed Imaging Radar, 1975

By:  Bryan, M.L.and Larson, R.W.


The study of ice in the upper great lakes, both from the operational and the scientific points of view, is receiving continued attention. Quantitative and qualitative field work is being conducted to provide the needed background for accurate interpretation of remotely sensed data. The data under discussion in this paper were obtained by a side-looking multiplexed airborne radar (slar) supplemented with ground-truth data. Because of its ability to penetrate adverse weather, radar is an especially important instrument for monitoring ice in the upper great lakes. It has previously been shown that imaging radars can provide maps of ice cover in these areas. However, questions concerning both the nature of the surfaces reflecting radar energy and the interpretation of the radar imagery continually arise. The analysis of ice in whitefish bay (lake superior) indicated that the combination of the ice/water interface and the ice/air interface is the major contributor to the radar backscatter as seen on the imagery. At these frequencies the ice has a very low relative dielectric permittivity (less than 3.0) and a low loss tangent. Thus, this ice is somewhat transparent to the energy used by the imaging slar system. The ice types studied included newly formed black ice, pancake ice, and frozen and consolidated pack and brash ice. (sims-isws)

Bryan, M.L., Larson, R.W., The Study of Fresh-Water Lake Ice Using Multiplexed Imaging Radar: Journal of Glaciology;
Vol. 14, NO. 72, P 445-457, 1975. 7 Fig, 19 Ref. Nasa Nas 3-18239. 

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