The influence analysis of reflectance anisotropic of canopy on the prediction accuracy of Cu stress based on laboratory multi-directional measurement

摘要

The atmosphere calibrated airborne and space borne hyperspectral images are the HDRF of canopy. The spatial nonuniformityof HDRF may result in inversion errors of the heavy metal stressing. In this paper, the HDRF of copperstressed plant samples under different illumination conditions was acquired with the laboratory hyperspectral simulationsystem called MHRS~2F. The difference between the HDRF of canopy and the BCRF of leaves was firstly discussed.Then the changes of spatial distribution of the HDRF for different copper concentrations and illumination conditionswere discussed. At last, the sensitivity of various vegetation indices to illumination and observation directions wascompared. By comparing the prediction accuracy of different vegetation indices on different observation directions andillumination conditions, the HVI and mRENDVI were found to be more stable and accurate.