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This paper explores the potential of Global Navigation Satellite Systems (GNSS) multipath signals for soil moisture retrieval, specifically focusing on Navigation with Indian Constellations (NavIC). Utilizing GNSS-Interferometric Reflectometry (IR) techniques, wavelet analysis is employed to extract the low-frequency signal sensitive to soil moisture from the reflected multipath signals. The reconstructed low-frequency multipath signal is then subjected to Lomb-Scargle Periodogram (LSP) analysis to determine multipath frequency. A comprehensive sensitivity analysis reveals the dependency of multipath frequency on field soil moisture, particularly in the presence of vegetation. The sensitivity varies across different crop growth stages, categorized by crop height. The Pearson correlation coefficient (r) for crop height less than one wavelength was 0.81 and for greater than one wavelength it was 0.67. The sensitivity of multipath frequency for soil moisture was 0.48 rad s−1 cm3 cm−3 and 0.47 rad s−1 cm3 cm−3 for crop height less than one wavelength and crop height greater than one wavelength respectively.This research underscores the potential of GNSS-IR techniques, incorporating wavelet analysis and LSP, for soil moisture sensitivity, especially in areas with varying vegetation and crop growth stages. [ABSTRACT FROM AUTHOR]

The present mathematical model is solved for the study of the effect of vertically aligned cracks present in the elastic half space on the propagation of elastic waves through the interface between double porosity solid and cracked elastic solid. Local fluid flow (LFF) between the inclusions (second fluid) and the host medium (first fluid) has been considered in double porosity solid which is possible due to wave propagation. This study follows Snell's law for reflection and refraction of an incident wave at the interface. Due to the presence of cracks in elastic half space, a loose bonding at the interface between these two media has been considered which is represented here as tangential slip. Final equation is framed in the form of Christoffel equation, which is solved analytically and found four reflected waves (three longitudinal body waves and one transverse body wave) and two refracted waves (one longitudinal body wave and one transverse body wave). The phase velocities and attenuation coefficients are calculated for each inhomogeneous wave. The expression of reflection and refraction coefficients, and energy shares of each of the reflected and refracted waves for a given incident waves is found in closed form. Numerical examples have been considered to discuss the effect of crack density, aspect ratio, local fluid flow, shear consolidation parameter and loose bonding parameter, etc. on energy shares by reflected and refracted waves. [ABSTRACT FROM AUTHOR]

The present study is focused on the numerical investigation in time domain of the deformation in thermoelastic material with one relaxation time (Lord and Shulman theory) with voids under dependence of modulus of elasticity and thermal conductivity on reference temperature. For dependency on reference temperature, we have taken two cases: (i) linear case and (ii) quadratic case. For numerical investigation, the finite element method with eight-/nine-noded isoparametric finite elements has been used. The results demonstrate that finite element method can reliably predict the deformation of the medium. Finite element method has an advantage over Laplace/Fourier transformation as the equations are solved directly in the time domain, but in Laplace/Fourier transformation, numerical inversion is quite complicated with possible errors. The comparison of these two cases has been discussed in result and discussion section for the temperature distribution, the displacement component, volume fraction field and the stresses. A comparison of Newmark method and Galerkin's method for time domain has been given though three-dimensional graphs. An appreciable effect of thermal relaxation times t0 is observed from the various results. [ABSTRACT FROM AUTHOR]