Correlation between Color of Subsurface Soil Horizons and Ground-Penetrating Radar Data

Abstract: The aim of the research was to analyze the relationship of color indicators of soil layers with the parameters obtained by ground-penetrating radar (GPR) profiling. Such parameters were the data of the spectral Fourier transform of the amplitude of the reflected pulse in the subsurface horizons of the soils of the Kamennaya Steppe area. GPR profiling was carried out by a Loza-V geophysical device. The diffraction points of reflected pulse amplitude corresponding to local soil horizons and groundwater surface were determined. The variability in the thickness of horizons and layers was calculated through the modules of amplitude maxima taking into account the conductivity of the horizon (dielectric permittivity and the rate of signal passage in a given medium). The procedure of verification of differentiation of sounding points was based on their comparison with real soil profiles and patterns. Statistical processing included the calculation of mean values, standard deviations, and frequencies of signal amplitude distribution; the use of the principal component method; and cluster analysis. Two polynomial models of connection of changes in parameters of the spectral Fourier transform of electromagnetic pulses in subsurface medium of chernozems with attributive parameters of formation of spectral pure colors of dominant wavelength (λi) were constructed. The indicative parameters included the conditional coefficient of pure color (Kλi), which corresponds to the addition functions in the tri-color colorimetric system MKO XYZ 1931, and its saturation, which is completely determined by the properties of the reflection coefficient (R) in the spectral range of λ 580–720 nm (red band). The calculated parameters of soil chromaticity obtained on the basis of these models were the prerogative for constructing the RGB model of soil layers and its visualization in graphic editors. © 2020, Pleiades Publishing, Ltd.