Studies of BRDF in conifer and deciduous boreal forests using the 4-scale model and airborne POLDER and ground-based PARABOLA measurements

An investigation of directional reflectance of boreal forests is conducted using airborne POLDER (1994) and ground-based PARABOLA measurements (1995) and the 4-Scale model (1997). The model simulates well the pronounced hotspots observed by POLDER and the slight bowl shape in the forward scattering direction observed by PARABOLA. The model is also used to demonstrate the importance of branch architecture in the directionality of NDVI calculated from the red and near infrared reflectance.