FLuorescence EXplorer (FLEX): an optimised payload to map vegetation photosynthesis from space

Abstract

The FLuorescence EXplorer (FLEX) mission proposes to launch a satellite for the global monitoring of steady-state chlorophyll fluorescence in terrestrial vegetation. Fluorescence is a sensitive probe of photosynthetic function in both healthy and physiologically perturbed vegetation, and a powerful non-invasive tool to track the status, resilience, and recovery of photochemical processes and moreover provides important information on overall photosynthetic performance with implications for related carbon sequestration. The early responsiveness of fluorescence to atmospheric, soil and plant water balance, as well as to atmospheric chemistry and human intervention in land usage makes it an obvious biological indicator in improving our understanding of Earth system dynamics. The amenability of fluorescence to remote, even space-based observation qualifies it to join the emerging suite of space-based technologies for Earth observation. FLEX would encompass a three-instrument array for measurement of the interrelated features of fluorescence, hyperspectral reflectance, and canopy temperature. FLEX would involve a space and ground-truthing program of 3-years duration and would provide data formats for research and applied science. Michael E (2006). FLuorescence EXplorer (FLEX): an optimised payload to map vegetation photosynthesis from space. ABSTRACTThe FLuorescence EXplorer (FLEX) mission proposes to launch a satellite for the global monitoring of steady-state chlorophyll fluorescence in terrestrial vegetation. Fluorescence is a sensitive probe of photosynthetic function in both healthy and physiologically perturbed vegetation, and a powerful non-invasive tool to track the status, resilience, and recovery of photochemical processes and moreover provides important information on overall photosynthetic performance with implications for related carbon sequestration. The early responsiveness of fluorescence to atmospheric, soil and plant water balance, as well as to atmospheric chemistry and human intervention in land usage makes it an obvious biological indicator in improving our understanding of Earth system dynamics. The amenability of fluorescence to remote, even space-based observation qualifies it to join the emerging suite of space-based technologies for Earth observation. FLEX would encompass a three-instrument array for measurement of the interrelated features of fluorescence, hyperspectral reflectance, and canopy temperature. FLEX would involve a space and ground-truthing program of 3-years duration and would provide data formats for research and applied science.

Evaluating the predictive power of sun-induced chlorophyll fluorescence to estimate net photosynthesis of vegetation canopies: A SCOPE modeling study

“…FLEX will operate in a tandem mission with ESA's Sentinel-3 satellite, the latter to provide atmospheric and land surface data needed for atmospheric corrections and accurate SIF characterizations. FLORIS will measure the radiance between 500 and 780 nm with a bandwidth between 0.3 nm and 2 nm (depending on wavelength), providing images with a 150 km swath and 300 m pixel size (Kraft et al, 2013;Moreno, Asner, Bach, et al, 2006). Such finely resolved spectral sampling will allow retrieval of the full broadband fluorescence emission spectrum and related products such as F total (i.e., integral of the fluorescence broadband spectrum).…”

Towards the quantitative and physically-based interpretation of solar-induced vegetation fluorescence retrieved from global imaging

“…After such studies and campaigns, in 2005, a full proposal for a dedicated mission to map vegetation fluorescence was again presented to ESA. Still named FLEX for historical reasons, the new concept was much more elaborated and technically mature (Moreno et al 2006). The mission was then selected by ESA for successive phases and reshaped in 2010 to be converted into a tandem-mission concept flying together with Sentinel-3 to share data and optimize resources.…”

Global Trends of Usage of Chlorophyll Fluorescence and Projections for the Next Decade

“…Chlorophyll fluorescence is an intense signal (with a yield of around 2% of the absorbed light) and requires little sample preparation [ 8 ], making it one of the most attractive techniques in plant phenomics. Several methods explore different properties of photosynthetic material via fluorescence, such as structure (confocal and epifluorescence [ 9 ]), energy transfer (time correlated to single-photon counting, fluorescence lifetime microscopy, or just steady-state fluorescence [ 10 , 11 ]), and charge recombination reactions (delayed fluorescence [ 12 , 13 ]).…”