FLEX/Sentinel‐3 Tandem Mission FLEX Bridge Study FINAL REPORT January 2016 ESA ESTEC Contract No. 4000112341/14/NL/FF/gp FLEX Bridge Study – Final Report – January 2016 ESA ESTEC Contract No. 4000112341/14/NL/FF/gp Gina H. Mohammed (P & M Technologies, Canada) (Chapters 1, 3, 4, 6-9) Roberto Colombo (University of Milano-Bicocca, Italy) (Ch. 2) Jose Moreno (University of Valencia, Spain) (Ch. 2, 5) Christiaan van der Tol (University of Twente, The Netherlands) (Ch. 4) Uwe Rascher - , Germany) (Ch. 3) Alexander Ač (Global Change Research Centre AS CR, Czech Republic) (Ch. 3) Luis Alonso (University of Valencia, Spain; and IBIMET-CNR, Italy) (Ch. 5) Marco Celesti (University of Milano-Bicocca, Italy) (Ch. 2) Sergio Cogliati (University of Milano-Bicocca, Italy) (Ch. 2) Alexander Damm (University of Zurich, Switzerland) (Ch. 2, 3) Dominic Fawcett (University of Zurich, Switzerland) (Ch. 2, 3) Jose Gomez-Dans (University College London and NERC/NCEO, United Kingdom) (Ch. 4) Claudio Henry (University of Zurich, Switzerland) (Ch. 3) Philip Lewis (University College London and NERC/NCEO, United Kingdom) (Ch. 4) Natasha MacBean (LSCE – L S C ’E v ) (Ch. 4) Federico Magnani (University of Bologna, Italy) (Ch. 4) Jacques Malaprade (University College London and NERC/NCEO, United Kingdom) (Ch. 4) Maria Matveeva - , Germany) (Ch. 3) Julie Olejníčková (Global Change Research Centre AS CR, Czech Republic) (Ch. 3) Dan Pernokis (P & M Technologies, Canada) (Ch. 4) Francisco Pinto - , Germany) (Ch. 3) Sabrina Raddi (University of Florence, Italy) (Ch. 4) Nastassia Rajh Vilfan (University of Twente, The Netherlands) (Ch. 4) Juan Pablo Rivera (University of Valencia, Spain) (Ch. 2, 4) Micol Rossini (University of Milano-Bicocca, Italy) (Ch. 2, 4, 5) Neus Sabater (University of Valencia, Spain) (Ch. 2) Anke Schickling - , Germany) (Ch. 3) Carolina Tenjo (University of Valencia, Spain) (Ch. 2) Wout Verhoef (University of Twente, The Netherlands) (Ch. 2, 4) Jochem Verrelst (University of Valencia, Spain) (Ch. 2) Jorge Vicent Servera (University of Valencia, Spain) (Ch. 5) Matthias Drusch (ESTEC, The Netherlands) Study Manager: ESA/ESTEC Technical Officer: Dr. Gina H. Mohammed Dr. Matthias Drusch Research Director Land Surfaces Principal Scientist P & M Technologies Mission Science Division (EOP-SME) 66 Millwood Street European Space Agency, ESTEC Sault Ste. Marie, Ontario P6A 6S7 Earth Observation Programmes Canada Postbus 299, 2200 AG Noordwijk The Netherlands 1 FLEX Bridge Study ESA Contract No: 4000112341/14/NL/FF/gp Subject: Final report Contractor: P & M Technologies *ESA CR( ) No: No. of volumes: 1 Contractor’s reference: 39451 ABSTRACT: The FLEX Bridge Study advanced approaches for retrieval and applications of solar-induced fluorescence (SIF) for assessment of photosynthesis and stress status in terrestrial vegetation, including development of a calibration/validation strategy for FLEX products. Specific advances included: (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 and 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 forms the foundation for subsequent science and applications development during FLEX mission development and deployment. The work described in this report was done under ESA Contract. Responsibility for the contents resides in the author(s) and organisation(s) that prepared it. Names of authors: Gina H. Mohammed (P & M Technologies, Canada) Roberto Colombo (University of Milano-Bicocca, Italy) Jose Moreno (University of Valencia, Spain) Christiaan van der Tol (University of Twente, The Netherlands) Uwe Rascher (Institute of Bio- and , Germany) Alexander Ač (Global Change Research Centre AS CR, Czech Republic) Luis Alonso (University of Valencia, Spain) Marco Celesti (University of Milano-Bicocca, Italy) Sergio Cogliati (University of Milano-Bicocca, Italy) Alexander Damm (University of Zurich, Switzerland) Dominic Fawcett (University of Zurich, Switzerland) Jose Gomez-Dans (University College London, United Kingdom) Claudio Henry (University of Zurich, Switzerland) Philip Lewis (University College London, United Kingdom) Natasha MacBean (LSCE – L S C ’E v ) Federico Magnani (University of Bologna, Italy) Jacques Malaprade (University College London, United Kingdom) Maria Matveeva - , Germany) Julie Olejníčková (Global Change Research Centre AS CR, Czech Republic) Dan Pernokis (P & M Technologies, Canada) Francisco Pinto (Institute of Bio- and Geosciences, Forschungsz , Germany) Sabrina Raddi (University of Florence, Italy) Nastassia Rajh Vilfan (University of Twente, The Netherlands) Juan Pablo Rivera (University of Valencia, Spain) Micol Rossini (University of Milano-Bicocca, Italy) Neus Sabater (University of Valencia, Spain) Anke Schickling - , Germany) Carolina Tenjo (University of Valencia, Spain) Wout Verhoef (University of Twente, The Netherlands) Jochem Verrelst (University of Valencia, Spain) Jorge Vicent Servera (University of Valencia, Spain) Matthias Drusch (ESTEC, The Netherlands) ESA Study Manager: Matthias Drusch **ESA Budget Heading: **Division: SM **Directorate: EOP * To be completed by ESA ** Information to be provided by ESA Study Manager 3 Table of Contents Table of Contents ............................................................................................................................ 5 Acknowledgements ......................................................................................................................... 9 Abstract ......................................................................................................................................... 11 Executive Summary ....................................................................................................................... 13 1. Introduction .............................................................................................................................. 21 2. Solar-induced fluorescence (SIF) retrieval optimisation and analysis ...................................... 25 2.1 Introduction ........................................................................................................................ 25 2.2 Data generation .................................................................................................................. 25 2.2.1 Extension of SCOPE-generated FLEX/S3 spectral database ......................................... 25 2.2.2 Generation of a synthetic Level-1b products dataset using FLEX End-to-End Mission Performance Simulator (FLEX-E) .................................................................... 26 2.3 Towards Level-2a products ................................................................................................. 26 2.3.1 Optimisation of the atmospheric correction algorithm using S3/FLEX ....................... 26 2.3.2 Optimisation of retrievals of the full SIF spectrum and contributions from Photosystem I & II ................................................................................................................. 32 2.4 Towards Level-2b products ................................................................................................. 38 2.4.1 Assessment of strategies to improve APAR estimates for calculation of yields ......... 38 2.4.2 Definition and derivation of additional SIF-derived indices ........................................ 44 2.5 Towards Level-2c products ................................................................................................. 47 2.5.1 Development of biophysical parameter retrieval algorithms for advanced exploitation of FLEX data products .............................................................................. 47 2.5.2 Simultaneous retrieval of canopy state variables by model inversion of integrated tandem mission data ................................................................................. 50 2.6 Conclusions ......................................................................................................................... 53 3. Development of vegetation stress indicators and applications ............................................... 55 3.1 Introduction ........................................................................................................................ 55 3.2 Stress indicators and applications ...................................................................................... 55 3.2.1 Results .......................................................................................................................... 55 3.3 Sources of variability and error in stress detection ............................................................ 62 3.3.1 Results .......................................................................................................................... 63 3.4 Linking HyPlant data to vegetation stress .......................................................................... 69 3.4.1 Results .........................................................................................................................