The structure of red-infrared scattergrams of semivegetated landscapes

A physically based linear stochastic geometric canopy-soil reflectance model is presented for characterizing spatial variability of semivegetated landscapers at subpixel and regional scales. Landscapes are conceptualized as stochastic geometric surfaces, incorporating not only the variability in geometric elements but also the variability in vegetation and soil background reflectance, which can be important in some scenes. The model is used to investigate several possible mechanisms which contribute to the often observed characteristic triangular shape of red-infrared scattergrams of semivegetated landscapes. Scattergrams of simulated semivegetated scenes are analyzed with respect to the scales of the satellite pixel and subpixel components