Function for Calculating Soil Dielectric Constant

Soil dielectric constant calculation is a crucial research topic in fields such as remote sensing, agriculture, and geophysics, playing a particularly vital role in soil moisture inversion. The Dobson model is a classical semi-empirical model used to estimate the complex dielectric constant of soil.

This model calculates both the real and imaginary parts of soil dielectric constant based on soil physical properties including volumetric moisture content, soil texture (such as percentages of sand, silt, and clay), and frequency parameters. A typical MATLAB implementation of the Dobson model function accepts soil physical parameters (moisture content, temperature, soil composition ratios) and electromagnetic wave frequency as inputs, then returns the complex dielectric constant.

The computational process within the function generally follows these key steps: Input parameter validation: Ensures that parameters like soil moisture content and frequency fall within reasonable physical ranges through conditional checks and error handling. Soil composition weighting calculation: Adjusts dielectric property contributions using weighted averages based on different soil component proportions (e.g., sand, clay ratios) through matrix operations. Dielectric constant computation: Calculates complex dielectric constant via Dobson's empirical formulas by combining dielectric properties of free water, bound water, and soil solids using complex number arithmetic. Temperature correction: Incorporates temperature effects on dielectric properties through polynomial fitting, typically applicable within 0°C to 50°C range using temperature compensation coefficients.

This function supports dielectric property estimation across various frequency bands including L, C, and X microwave bands, making it widely applicable for soil moisture remote sensing inversion and surface scattering modeling in environmental studies.