Soil surface backscatter model using FDTD method

The effect of inhomogeneous soil properties, such as wetting and drying fronts, on backscattering behaviour is examined. A FDTD model is developed to simulate the electromagnetic backscattering by a random three-dimensional soil surface excited by a sinusoidal plane wave of 5.3 GHz. The total-field/scattered-field formulation is used along with Berenger's (1994) perfectly matched layer (PML). A number of three-dimensional random surfaces with known surface statistical properties are generated and computed to obtain the value of the backscattering coefficient. The FDTD results are compared with existing theoretical and empirical models.