HR: 1340h
AN: C23A-0928    [Abstracts]
TI: An Assessment Of The Correlation Between Radar Backscatter And Statistical Parameters Of Snow Microstructure
AU: * Yurchak, B S
EM: yurboris@umbc.edu
AF: University of Maryland Baltimore County, GEST, 8800 Greenbelt Rd., Greenbelt, MD 20771,
AB: Snow microstructure irregularities are one of the numerous factors that affect radar backscatter. In this work, the correlation is retrieved between the volume component of radar backscatter and the statistical parameters of snow microstructure. This study uses the "slice" approach: snow particles close to the front of incident radar wave are considered to be approximately at the same distance from the radar. Therefore, these particles reflect incident electromagnetic wave coherently. Each slice is much narrower than the radar wavelength in the wave propagation direction. In the transverse plane the slice has spherical configuration (in accordance with the spherical wave front) within the cross section of the backscatter volume, which, in turn, is formed by main lobe of the antenna pattern. The snow radar equation, which is based on the slice model of backscatter volume, is derived. The equation includes contributions to the backscatter from uncorrelated small-scale fluctuations of snow reflectivity. It is shown that the average power of an echo signal is proportional to radar reflectivity, i.e. to the sixth moment of the snow particles' size distribution function, for the case of Poisson fluctuation of particle concentration within the slices and uncorrelated small-scale snow reflectivity fluctuations within a backscatter volume. In this case the known semi-empirical model of volume backscatter is valid. Overall, the volume component of the backscatter coefficient depends on the first three moments of the particle size distribution function. For completely homogeneous microstructure the volume component of return signal is zero. Preliminary estimates of microstructure parameters of dry snow zone of the Greenland Ice Sheet, which can cause the observable very low radar backscatter, is presented.
DE: 0700 CRYOSPHERE (4540)
DE: 0726 Ice sheets
DE: 0736 Snow (1827, 1863)
DE: 0758 Remote sensing
SC: Cryosphere [C]
MN: 2007 Fall Meeting