Phase: RAMI 2
The drat model is an efficient Monte Carlo ray tracing (MCRT) model, which is driven by 3D locations and orientations of scattering elements (including triangles, spheres, cylinders, spheroids, ellipsoids, Bezier patches etc.) combined with descriptions of radiometric properties of the primitive set (reflectance, transmittance at specified wavelengths). This model has been used in a number of simulation studies and has been shown to agree with both measurements and other models of canopy scattering (Liang, 2004; Pinty et al., 2004).