The forest reflectance model by Nilson and Peterate a satellite or aerial imagery-based forest management son has been extensively modified. Leaf optics model system, forest reflectance models capable of acting as an PROSPECT2, atmosphere radiative transfer model 6S, interface between the images and forestry databases are and homogeneous canopy reflectance model MCRM have required. These models should be able to make maxibeen incorporated into the model. The new model works mum use of the forestry data contained in the database in the spectral region 400-2500 nm with the same set of and allow to simulate the optical images, for example, in input parameters. Any Sun and view directions are alterms of standwise ground-level reflectance factors. Origlowed. Sample calculations are compared to published inally, the forest reflectance model described in Nilson data on the old black spruce stand of the BOREAS and Peterson (1991) has been derived just from these Southern Study Area. The new model is able to adestarting points. The previous version of the model quately simulate both the reflectance spectrum and anguneeded several improvements. First of all, to make use lar distribution. The determination of the whole set of of multiangular remote sensing data, the model should input parameters of the model is a difficult practical be modified into a multiangular version. Second, a multiproblem. Β©Elsevier Science Inc., 2000 spectral version of the model is required to study the relations between leaf biochemical and high spectral resolution reflectance data. Several improvements were also β’ Several tree classes of different size and/or spe-*Tartu Observatory, To Λravere, Estonia cies are possible. Within each class, trees are