Scale Conversion Of Spectral Simulation Based On LAI And BRDF Model

Forests,as a principal component of terrestrial ecosystems,account for nearly 25% of the world's land and play an important role in the ecological balance and environment.Forests are the main important material basis and environment guarantee for the human,but also structure the most complex and most biologically diverse natural ecosystems.It is practically and theoretically significant for people to enhance the supervision of importance the forest and scientific utilization of forest resources,to in-depth study the forest and description the changes of carbon,water and energy.Leaf Area Index(LAI)is defined as the one-sided green leaf area per unit ground surface area,and it is one of the important parameters of canopy structure.LAI has become a hot academic issue in recently years.Leaf is the main alimentative organ of the plant for the material energy exchange with the outside world major organs.And photosynthesis occurs almost exclusively in the leaves.Transpiration also is forced from the leaves through hydathodes.LAI is already considered reference index for describe the forest resources worldwide,study the energy cycle and matter circulation between vegetation and the outside world.In this study,the leaf area index in Daxing'anling was retrieved by using remote sensing data.As an important vegetation parameter,foliage reflectance has extraordinary significance for the study of forest,while the pixel information obtained from remote sensing image is canopy reflectance information.This study using four-scale model and PROSOECT model simulation canopy reflectance,establish the look-up-table of foliage reflectance and canopy reflectance.Using MODIS Surface Reflectance products(MOD09A1 date),Leaf Area Index products(MOD15A2 date),and land cover types(MCD12Q1 data),inversion the foliage reflectance in the August,2014,Daxing'anling region,using red band and infrared band.Making accuracy test using foliage reflectance achieved by SVC-1024 i in field.Results show that,measured data and inversion data have better correlation(R2 is 0.789 and 0.796),and suggest that the inversion result using four-scale model establish the look-up-table inversion foliage reflectance is feasible.