The results of measurements of the complex permittivity at the range of 100 MHz - 40 GHz and the conductivity of the water out of the reservoirs of Tomsk and Kemerovo regions and the Altai Territory are presented in the article. The method of the open-end-coaxial was applied. The conductivity was measured with LCR-meter at a frequency of 100 kHz. All the measurements were performed at temperatures of 10°C and 23°C. The samples are varied significantly in the values of conductivity, which is related to the geographical sampling place. Differences in permittivity values are greater at the low temperature and low frequencies and at the same time they are also significant at the high temperature and at high frequencies. The results of this study in order to improve the reliability of the analysis of the pollution degree and water salt content of natural water reservoirs should be taken into account the measurement made at wide frequency range.
Reflection and transmission coefficients of marsh vegetation such as mosses, grasses, shrubs, were measured using coaxial line at the range of 100 MHz – 18 GHz. Weight moisture content of the samples varied from 3 to 100%. The measurement results show that the absolute value of the reflection coefficient for marsh vegetation samples dependent on both moisture content and frequency of the electromagnetic wave, and also on the plant species. The study results will be used in the next step – the development of a mathematical model of the complex permittivity for the determination of marsh vegetation species in order to monitor of climate changing.
The present work is devoted to the measurement of the dielectric properties of mosses and lichens in the frequency range from 500 MHz to 18 GHz. Subjects of this research were three species of march vegetation – moss (Dicranum polysetum Michx), groundcedar (Diphasiastrum complanatum (L.) Holub) and lichen (Cladonia stellaris). Samples of vegetation were collected in Tomsk region, Western Siberia, Russia. Complex dielectric permittivity was measured in coaxial section by Agilent Technologies vector network analyzer E8363B. Green samples was measured for some moisture contents from 100% to 3–5 % during a natural drying. The measurements were performed at room temperature, which remained within 21 ÷ 23 ° C.
The frequency dependence of the dielectric constant for the three species of marsh vegetation differ markedly. Different parts of the complex permittivity dependency on moisture were fitted by line for all frequency points. Two break point were observed corresponding to the transition of water in the vegetation in various phase states. The complex permittivity spectra of water in the vegetation allow determining the most likely corresponding dielectric model of water in the vegetation by the method of hypothesis testing. It is the Debye’s model. Parameters of Debye’s model were obtained by numerical methods for all of three states of water. This enables to calculate the dielectric constant of water at any frequency range from 500 MHz to 18 GHz and to find the parameters of the dielectric model of the vegetation.
This paper describes a comprehensive approach which combines the application of OKO-2 ground penetrating radar, conventional method of cross sectioning accepted in edaphology, soil-testing parameters, mobile and laboratory research of dielectric permittivity for stratified soil cover research. Dielectric characteristics measurements of selected contact samples by the waveguide–coaxial technique showed a correlation between electrophysic characteristics of soil with soil moisture and density. Location of deep aquifers was detected and the real local topography was restored. Research was performed within the Timiryazevskoye forest district near Tomsk. Comparing the results of radar non-destructive sounding and contact measurements demonstrated high correlation of detected structural soil features. The suggested approach provides a solid basis for verifying the non-contact radiophysical methods of research in the interests of rational nature management and land utilization.