An investigation of remotely-sensed soil depth in the optical region
The remotely-sensed soil depth in the visible and near-infrared (near-IR) spectral region is investigated by using a numerical radiative transfer model of the coupled atmosphere and soil media. The sensible depth is determined by examining the downward hemispheric transmittance profile, hemispherical reflectance, and bidirectional reflectance with different solar zenith angles at different wavelengths. The particle size distributions and particle shapes are also evaluated. Under an ordinary condition, the sensible optical depth is about 3, which corresponds to geometric depth of 4-5 times the particle effective radius.