To better understand the role of vegetation in the carbon cycle and the effects of global warming on it, LMD is developing new airborne lidar observation instruments, using a laser beam to probe photosynthetic activity through chlorophyll fluorescence. The flight measurements carried out with the LASVEG instrument in April 2026 between the Gers and Haute-Garonne regions and in northern Hérault made it possible, for the first time worldwide, to simultaneously record over the same target: Laser-Induced Fluorescence (LIF) on two channels, Sun-Induced Fluorescence (SIF), and the vertical structure of trees.

The LASVEG (LASER Vegetation) instrument, designed and developed at LMD, is an airborne fluorescence lidar combined with a hyperspectral radiometer and two spectroradiometers centred on the atmospheric oxygen absorption bands. Green laser pulses at 532 nm, emitted from the SAFIRE ATR42 aircraft, induce chlorophyll fluorescence in the red spectral region on two channels at 690 nm and 740 nm. By measuring these signals accurately, it is possible, using dedicated analysis algorithms, to characterize the dynamics of photosynthetic activity at large scales.

This project, led by Yves Goulas and Abderrahmane Ounis at LMD, will make it possible to compare the airborne measurements with those from ground-based instruments and will help prepare future satellite missions for vegetation observation, in particular the FLEX mission of the European Space Agency (ESA).

To learn more about LASVEG and the remote sensing of photosynthesis:

https://polipapers.upv.es/index.php/raet/article/view/3982/4850

https://journals.openedition.org/hrc/11043