Optical versus radar roughness in agricultural tillage

The relationship between soil roughness as measured with an optical roughness meter and soil roughness causing microwave radar scatter is explored. Optically measured soil profiles and associated soil moisture measurements will be analyzed using the FDTD technique to solve for the electromagnetic fields within the soil. Through the volume equivalence theorem these fields can be shown to generate the radar backscatter. The microwave roughness can then be defined in terms of the shape of these equivalent currents in the soil. Changes in both the rms surface roughness and the surface autocorrelation between optical and microwave roughness are shown