SUNLIT/SHADED LIGHT-USE EFFICIENCY ESTIMATION OF CROPLAND USING HYPERSPECTRAL DATA

摘要

The light-use efficiency (LUE) is one of critical parameters in the terrestrial ecosystem production studies. Although some published paper on the LUE in cropland had used hyperspectral data, lack of study in literature investigated the cropland LUE using the surface reflectance with high spatiotemporal and high spectral data with multiple angles. Based on the observed reflectance and flux data, a Bidirectional Reflectance Distribution Function (BRDF) of vegetation index (Photochemical Reflectance Index, PRI) at continuous time series was established by integrating of a semi-empirical kernel-driven BRDF model (RossThick-LiSparse), a footprint model (the Simple Analytical Footprint model on Eulerian coordinates for scalar Flux, SAFE-f) and a LUE model. Besides, based on the sky-condition (direct/diffused radiation) data, the relationships between the PRI and sunlit/shaded LUE under corresponding sky conditions were established.