Temporal attributes of the bidirectional reflectance for three boreal forest canopies

Multidirectional ground-based optical measurements were acquired along tramways above and beneath three important boreal forest canopies to characterize the complete radiative transfer of visible through shortwave infrared wavelengths. The three forest canopy types exhibited bidirectional reflectance features that were distinctively different from each other not only in their magnitudes of reflectance in a given spectral wavelength band and at forward and backscatter angles but also in their diurnal and seasonal changes. The above-canopy data analyses indicate that each of these forest types must be considered as having unique bidirectional reflectance distribution functions and should be modeled individually for both direct (e.g. albedo) and indirect (e.g. biophysical parameter assessments) applications in the quantitative remote sensing of the boreal forest biome.