Maple Canopy

PMT Logo

LMD Logo Jülich Logo UVAL Logo


Seven organizations from seven countries
were involved in the Photosynthesis Study.
Click the logos to visit their websites.

About the FLEX Photosynthesis Study

This study targetted the linkage between solar-induced chlorophyll fluorescence and photosynthesis in terrestrial vegetation.  A dedicated photosynthesis model based on state-of-the-art existing modules was developed and implemented.  We also developed and tested a prototype algorithm to derive photosynthesis from FLEX tandem mission measurements.

The aim was to be able to map terrestrial photosynthesis from space by measuring vegetation fluorescence emission.  Scientific objectives of the study were:

  • To assess the quality of fluorescence-derived photosynthesis data against classical optically-based methods (the fraction of absorbed photosynthetically active radiation times Light Use Efficiency).
  • To address in more detail temporal and spatial scaling issues (from towers to satellite footprints).
  • To identify and characterise the effects of different types of stress on fluorescence and photosynthesis (especially drought and freezing air temperatures).
  • To indicate potential applications and usage of the novel fluorescence observations.

The potential of fluorescence to serve as an early indicator of stress – that is, before damage is irreversible – is a major aspect to be considered in the exploitation of FLEX measurements, since reflectance changes often are detectable only in dramatic or advanced cases of physiological strain.  Furthermore, visible plant colour does not matter to fluorescence.

The Photosynthesis Study was part of the package of parallel study activities needed for assessment of the FLEX candidate mission.

To read or download the Final Project Report, see below.

To read about the follow-up FLEX Bridge Study, click here.

You can visit the ESA FLEX Project Page by clicking HERE.

   Photosynthesis Study Project – Final Report

2012 FLEX/Sentinel-3 Tandem Mission Photosynthesis Study – FINAL REPORT

PMT / Gina Mohammed – 2014-07-28

Gina H. Mohammed, Yves Goulas, Federico Magnani, José Moreno, Julie Olejnícková, Uwe Rascher, Christiaan van der Tol, Wout Verhoef;  Alexander Ac, Fabrice Daumard, Alexander Gallé, Zbynek Malenovský, Dan Pernokis, Juan Pablo Rivera, Jochem Verrelst;  Matthias Drusch.

Acknowledgements:  Sabrina Raddi, Marijke van der Tol, Antonio Volta, Elena Mezzini, Karel Klem, Frantisek Zemek, Ismael Moya, Anke Schickling, Luis Alonso, and Jesús Delegido Gómez;  FLEX Mission Advisory Group, including Elizabeth (Betsy) Middleton, Andreas Huth, Ladislav Nedbal, and Franco Miglietta;  ESA: Stefan Kraft, Umberto Del Bello, and Dirk Schüettemeyer.

The PS Study developed and tested a mechanistically-based model to link steady-state chlorophyll fluorescence with photosynthesis (an advancement of the SCOPE canopy model).  The Study also identified steady-state or solar-induced fluorescence (SIF) features that can be useful as indicators of stress effects from water deficit, temperature extremes, and nitrogen insufficiency, using red and far-red fluorescence peaks and their ratios.

A key finding from both the modelling initiative and the stress evaluations was the inherent value of having both the red and far-red fluorescence emission peaks for applications.  This underscores the unique advantages of FLEX, since its FLORIS sensor would be optimized to extract these spectral features with appropriate spatial and spectral detail.

The FULL REPORT file contains the Abstract and Executive Summary (and the latest Errata sheet), although these are also provided as separate files.  The Cover Title Page is intended only for printing a cover on cardstock, so it is not included within the main document.

To download an item, right-click the VIEW link and use your web browser's "Save As" or "Save Link As" function.

The Final Report is laid out with page parity (all sections start on an odd page), so there are alternating blank pages at the very beginning of the PDF file.

PDF file (5.19mb) – FULL REPORTView
PDF file (180 kb) – COVER TITLE PAGE Only (for cardstock)View
PDF file (392 kb) – EXECUTIVE SUMMARYView
PDF file (229 kb) – ABSTRACTView
PDF file (179 kb) – ERRATAView