FLEX EE8 Concept

ESA FLEX Earth Explorer 8 Concept / ESA Image

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Nine organizations from eight countries
were involved in the FLEX Bridge Study.
Click the logos to visit their websites.

About the FLEX Bridge Study

The FLEX Bridge Study advanced the work of the PS Study and PARCS projects by addressing priorities identified in these studies and in ongoing FLEX preparatory activities.  The goal of the FLEX Bridge Study was to optimize approaches for SIF retrievals and applications in the assessment of photosynthesis and stress status in terrestrial vegetation, including the development of a calibration/validation strategy for FLEX products.

Scientific objectives of the study were:

  • To address priorities identified by previous studies and in ongoing FLEX preparatory activities.
  • To optimize the fluorescence retrieval algorithm developed under the PARCS project.
  • To optimize the photosynthesis retrieval model (SCOPE v1.53) and its related algorithm developed under the PS Study.
  • To consolidate and develop retrievals for additional Level 2 data products.
  • To further exploit applications in photoynthesis modelling and stress detection.
  • To develop a calibration/validation strategy for FLEX products.

A key finding in our previous work is the inherent value of having both the red and the far-red fluorescence emission peaks for applications.  This underscores the unique advantages of FLEX and its FLORIS sensor which will be optimized to extract these spectral features with appropriate spatial and spectral detail.  Furthermore, visible plant colour does not matter to fluorescence.

FLEX Bridge formed a foundation for subsequent science & applications development during mission development and deployment.

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

Find out more about Earth Explorer 8 by clicking HERE (or HERE).

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

   FLEX Bridge Study Project – Final Report

2014 FLEX/Sentinel-3 Tandem Mission FLEX Bridge Study – FINAL REPORT

PMT / Gina Mohammed – 2016-01-14

Gina H. Mohammed (Study Manager), Roberto Colombo, José Moreno, Christiaan van der Tol, Uwe Rascher;  Alexander Ač, Luis Alonso, Marco Celesti, Sergio Cogliati, Alexander Damm, Dominic Fawcett, José Gomez-Dans, Claudio Henry, Philip Lewis, Natasha MacBean, Federico Magnani, Jacques Malaprade, Maria Matveeva, Julie Olejnícková, Dan Pernokis, Francisco Pinto, Sabrina Raddi, Nastassia Rajh Vilfan, Juan Pablo Rivera, Micol Rossini, Neus Sabater, Anke Schickling, Carolina Tenjo, Wout Verhoef, Jochem Verrelst, Jorge Vicent Servera;  Matthias Drusch (ESA/ESTEC Technical Officer).

Acknowledgements:  Gustau Camps-Valls, Daniel Kovác, MaPilar Cendrero Mateo, Silvia Garbari, Luis Guanter, Ari Kornfeld, Jordi Muńoz-Marí, Caroline Nichol, Cinzia Panigada, Patrick Rademske, Fabian Schneider, Giulia Tagliabue, Sebastian Wieneke, and Mat Williams;  FLEX Mission Advisory Group, including Yves Goulas, Andreas Huth, Elizabeth (Betsy) Middleton, Franco Miglietta, and Ladislav Nedbal;  ESA: Stefan Kraft, Umberto Del Bello, and Dirk Schüettemeyer.

The FB Study has advanced approaches for retrieval & applications of solar-induced fluorescence (SIF) for assessment of photosynthesis & stress status in terrestrial vegetation, including development of a calibration/validation strategy for FLEX products.  Specific advances include:  (i) optimisation of SIF retrieval algorithms, formalisation of fluorescence-derived indices, and development of biophysical products;  (ii) SIF-photosynthesis model improvements and evaluation of data assimilation techniques;  (iii) testing of stress indices, extension of the range of potential applications, and evaluation of non-photochemical protection mechanisms;  and (iv) development of calibration/validation strategies, including metrics for validation error & product accuracies, definition of FLEX Level 2/3 products and their validation plan, and definition of a common protocol and state-of-the-art instruments to be used for estimation of fluorescence in the context of cal/val activities.  This activity now forms the foundation for subsequent science & applications development during FLEX mission development & deployment.

Whereas much of the space-based SIF detection to date has focused on the far-red fluorescence – owing to the fact that the sensors were not specialised for full fluorescence retrievals – current information is incomplete and limits the ability to derive important interpretive information for identifying & tracking stress effects and also for quantification of photosynthetic rates.  Both the visible and near-infrared spectra are important for retrieval of both red and far-red fluorescence peaks, peak wavelength positions & shifts, and ancillary indices such as PRI and NDVI (or EVI).

The FULL REPORT file contains the Abstract and Executive Summary (and the latest Errata sheet if applicable), 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 (6.97 mb) – FULL REPORTView
PDF file (482 kb) – COVER TITLE PAGE Only (for cardstock)View
PDF file (716 kb) – EXECUTIVE SUMMARYView
PDF file (372 kb) – ABSTRACTView
PDF file (363 kb) – ERRATAView