About the Possibility of Layer Density
and Wetness Determination in the Snow Cover by Reflectometry
E.V. Vasilenko1, Leonid Kanaev2, and V.P. Smirnov3
A system including the measuring line, automatic impulse reflectometer of picosecond range and
PC/AT, connected to the reflectometer with COM-port, is presented in this article. A system ensures
registration of the profile of the reflection factor along the measuring line depending on the snow
physical parameters in which the line is set; inversion of the reflection profile to the profiles of the
components of the complex permittivity e′ + je′′; calculation of the profiles of the snow volume
wetness w(e′′) and snow dry density p(e', w). At the frequency of 100 KHz, the measuring line is
sounded at t = 0 by the voltage unit step at the wave front of the picosecond length. Reflections in the
beginning of the line (x = 0) at the different moments t > 0 are the result of the line heterogeneities at
some distance x > 0 and can be measured with the stroboscopic method. Observations at the discrete
moments ti > 0, i = 1, 2...1024 correspond to discretization of the measuring line along axis X to 341
layers with three sublayers in the layer. Reflection signals for 1024 two-byte values are being con-
verted into binary code and recorded in RAM to its address. On PC/AT inquiry, the reflectometer
outputs into communication channel 1024 two-byte values of the reflection signals. This file of
values is used in PC/AT together with the stored files of the reflection signal values for the empty line
to calculate the wave parameters Sk, Dk, Zk for all layers having numbers of k = 1, 2...341. The
developed program of the Sk, Dk, Zk sublayer calculations supplies the method of the solution of the
direct and inverse problems of scattering in the heterogeneous media by algebrazation of the non-
line wave equations (method has been proposed by C.Q. Lee in 1982).
The same method (in sublayers) is used to calculate the values e′ and e′′ and values Wk ( e′′ ), ρ
k
k
k
( e′ , wk). While testing meter at the multi-layer snow density at the total depth of 120 cm, and as the
k
density changes from 0.4 to 0.08 g/cm3 and layer depth from 6 to 40 cm, we can identify the layers
between air and fresh fallen snow at a density of about 0.08 g/cm3.
1 Academpribor,
700125, Academgorodok, Tashkent, Uzbekistan
2 Central Asian
Research Hydrometeorological Institute (SANOGMI), Republic of Uzbekistan, 700052,
Tashkent, K. Makhsumov st., 72, Uzbekistan
3 SPE "Hydrometpribor," 700084, Kh. Asomova, 4, Tashkent, Uzbekistan
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