Estimating subpixel surface roughness using remotely sensed stereoscopic data

Surface roughness at the 10^-2-10¹ m scale is estimated using the ratio between the reflectances of the surface measured from two view angles. As reflectance is dependant on surface roughness at these scales, this ratio provides us with a proxy for relative surface roughness within a single image that is largely independent of surface composition. Roughness estimates using stereoscopic data with 15-m spatial resolution from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) in Death Valley, California and ground based stereoscopic measurements at the ∼1-m scale were both found to be in good agreement with observed surface roughnesses.