Applications of laser-induced fluorescence for remote sensing

Recent experiments conducted using a ground-based lidar have shown that laser-induced fluorescence spectral emissions from green plants are detectable from a remote platform. A pulsed Nd-YAG laser emitting at 532 nn was used as an excitation source. The fluorescence maxima in Populus tree were found to be at 685 nm and 740 nn. An increase of the ratio 685/740 nm between the intensity maxima of the fluorescence spectra was observed for that tree in the case of water stress. The morphological differences or difference in the photosynthetic properties between the two sides of the leaves cause differences between the ratios of the intensity maxima at 685 nm and 740 nm of the fluorescence spectra observed in cases of different geometries of measurement during the laboratory study.