A Scale Transform Method for Leaf Area Index Retrieved from Multi-Resolutions Remote Sensing Data

Scaling effect of leaf area index (LAI) in remote sensing field means that values of LAI derived from different resolutions images also differ. The foundation of discussing LAI scaling effect problem is accurately retrieving LAI values from remote sensing images, and trying to exclude the influence of other factors. A hybrid model for continuous vegetation is chosen to retrieve LAI from reflectance images of 2.5 m, 10 m SPOT as well as 250 m and 500 m MODIS data. The task of scaling transform of LAI at different scales is deriving the expectation of LAI value at one specific scale from values of other scales. A formula for transforming LAI values at different scales is presented and successfully applied on these remote sensing images. The application results match well with ground truth.