Group on Earth Observation Webinar

1. Group on Earth Observation Webinar 28 June 2013 Steef Peters + GLaSS Partners & advisory board http://www.glass-project.eu/ GEO webinar, 2013-06-28

2. Outline • Consortium • Rationale for GLaSS • Scope and overall aim • Specific objectives • Project structure and phases • Sentinel 2 and 3 characteristics • Validation • Case studies • Atmospheric correction questions • Algorithm development questions • Expected achievements • Collaborations 2

3. The consortium • Steef Peters, Annelies Hommersom, Kathrin Poser, Nils de Reus, Marnix Laanen, Semhar Ghezehegn: Water Insight, Wageningen, Netherlands • Sampsa Koponen, Kari Kallio, Jenni Attila, Timo Pyhälahti, Mikko Kervinen, Saku Anttila: SYKE, Helsinki, Finland • Karin Schenk, Thomas Heege, EOMAP team: EOMAP, Oberpfaffenhofen, Germany • Marieke Eleveld, Steef Peters, VU/IVM, Amsterdam, The Netherlands • Ana Ruescas, Norman Fomferra, Carsten Brockmann, Kerstin Stelzer: Brockmann Consult, Geesthach, Germany • Claudia Giardino, Mariano Bresciani, CNR, Milano, Italy • Krista Alikas, Anu Reinart, Kristi Uudeberg, Ilmar Ansko, Martin Ligi, Tartu Observatory, Estonia • Petra Philipson, Niklas Hahn: Brockmann Geomatics Sweden, Stockholm, Sweden 3

4. Advisory board Prof. Yunlin Zhang (China: Taihu Lake Laboratory Ecosystem Research Station, Nanjing Institute of Geography and Limnology) Prof. Arnold Dekker (Australia: CSIRO, aquatic earth observation research team within the Environmental Earth Observation research group) Dr. Steven Greb (USA: senior scientist at the Wisconsin Department of Natural Resources) 4

5. consortium + advisory board 5

6. Rationale for GLaSS • Man-induced processes (eutrophication, influx of suspended solids, acidification) influence surface water quality • Largely unknown effect of climate change • and global warming • Water quality focus of monitoring agencies and the public, subject • of several European Directives and regional conventions • Integrated approach towards watershed and surface water quality management required, • based on a scientific understanding of the spatio-temporal aspects • of the processes and their interactions 6

7. Lakes in the North are more rapidly becoming warmer Most lakes are becoming warmer In deep lakes global warming could cause semi-permanent stratification

8. Pressures on lakes (withdrawal, waste) are increasing Precipitation relocation (droughts or excess wet periods) caused by global climate change can have severe consequences for lakes

9. Scope and overall aim • Earlier EC studies (e.g. Geoland and Geoland-2) approached inland water quality from a modeling point of view, not using satellite observations for model calibration and validation • Advent of Sentinel 2 and 3 with their high spatial and temporal • resolution will make such monitoring, model calibration and validation • feasible • GLaSS intends to contribute to integrated studies with innovative, detailed and reliable spatio-temporal monitoring information on key water quality aspects to underpin new policy making and management options 2013 or 2014 or...2015 9

10. 1001011010101010000111010100010011101001010100010100110010110101010100001110101000100111010010101000101001001011010101010000111010100010011101001010100010100100101101010101000011101010001001110100101010001010010010110101010100001110101000100111010010101000101001100101101010101000011101010001001110100101010001010010010110101010100001110101000100111010010101000101001001011010101010000111010100010011101001010100010100 Specific objectives Prepare for use of Sentinel data in the context of lakes and reservoirs Ingest large quantities of Sentinels data Automatic processing to higher level products Data-mining and search techniques for large quantities of data Access tools for the wider group of space data users Demonstrate applications including data validation activities Attract active participation of researchers and students Activities in the global domain 10

11. Project structure 11

12. Who are the users?

13. Project phases Preparation, inventory of user requirements & system specification Implementation of additional tools (data mining and improved algorithms) System implementation Trainings and course ware development Validation of results Global use cases 13

14. Detailed project structure

15. Sentinel 2: properties

16. Note the low SNR levels... MERIS SNR > 1000 CDOM @higher concentrations Case1 Chl-a band ratio TSM from any band 2..6 depending on concentration range Case2 Chl-a band ratio

17. Sentinel-3 Optical Revisit time and coverage Optical missions: Short Revisit times for optical payload, even with 1 single satellite • Data delivery timeliness: • Near-Real Time (< 3 hr) availability of the L2 products • Slow Time Critical (STC) (1 to 2 days) delivery of higher quality products for assimilation in models (e.g. SSH, SST)

19. OLCI: Ocean and Land Colour Instrument comparison to MERIS Pushbroom Imaging Spectrometer (VIS-NIR) – similar to MERIS • Key Improvements: • More spectral bands (from 15 to 21): 400-1020 nm • Broader swath: 1270 km • Reduced sun glint by camera tilt in west direction (12.20°) • Absolute (relative) accuracy of 2% ( relative 0.5%) • Polarisation sensitivity < 1% • Full res. 300m acquired systematically for land & ocean • Reduced res. 1200m binned on ground (L1b) • Improved characterization, e.g. straylight, camera boundary characterization • Ocean coverage < 4 days, (< 2 days, 2 satellites) • Timeliness: 3 hours NRT Level 2 product • 100% overlap with SLSTR • => Improved L2 products e.g., Cla, Transparency, TSM, Turbidity, PFTs, HAB, NDVI, MGVI, MTCI, faPAR, LAI

20. The GLaSS system

21. The GLaSS system Source: GLaSS D2.1 User requirements report: CNR, SYKE, VU/VUmc, BC, TO, BG, 2013-05

22. Source: GLaSS D2.1 User requirements report: CNR, SYKE, VU/VUmc, BC, TO, BG, 2013-05

23. BC: Expansion of BEAM withRapid Miner • Freely available open-source data mining and analysis system • GUI mode, server mode (command line), or access via Java API • Simple extension mechanism • More than 500 operators for data integration and transformation, data mining, evaluation, and visualization • Standardized XML interchange format for processes • Graphical process design for standard tasks, scripting language for arbitrary operations

24. Data Visualisation

25. Graphical Application Builder

26. Trained Model (Decision Tree)

27. Validation • validation of L2 reflectance and L2 water quality products in nearby lakes 27

28. TO: Study sites: lakes Lake Peipsi and Võrtsjärv

29. Water remote sensing group in Tartu Observatory Dr. Anu Reinart & colleagues Underwater light field, optical properties of lakes, MERIS validation )

30. Transect measuremets in Lake Peipsi

31. AERONET ? Garda WISP-3 Flow-through systems ASD-FR 0+ 0- Water-lab (Spectrophotometer, HPLC) Fluorimeters Ramses ac9 H6 Commercial software: ENVI, ArcGIS ATCOR, MODTRAN Hydrolight-Ecolight (5.0) CNR Facilities Sun-photometer 31

32. CNR-Data Starting data (2/2) Remotely sensed 32

33. SYKE • Validation • ASD spectrometers, WISP3? • SYKE laboratory • CDOM dominated • lakes

34. BG: Lake Vänern Aeronet-OC station at Pålgrunden Inlet – Bay of Mariestad • Chl: 8.04 ug/l • SPM: 2.49 mg/l • CDOM: 1.57 m-1 • Secchi: 2.9 m • Chl: 1.96 ug/l • SPM: 0.63 mg/l • CDOM: 1.06 m-1 • Secchi: 6.2 m Clear water • Chl: 35.79 ug/l • SPM: 30.49 mg/l • CDOM: 3.20 m-1 • Secchi: 0.4 m River mouth • Chl: 11.5 ug/l • SPM: 4.53 mg/l • CDOM: 4.68 m-1 • Secchi: 1.8 m Dättern Foto & Data: A. Hommersson & S.Kratzer (SU)

35. Monitoring service

36. IVM + WI : Lake Marken & Lake IJssel

37. Lake IJssel match-up collection Above water reflectance measured using Wisp-3 Spectroradiometer (in cooperation with University Twente) Continuous measurements of Chl-a fluoresence

38. Case studies Shallow lakes with high eutrophication and potentially toxic algae (Lake Peipsi, Lake Ijssel) Small lakes with high CDOM concentration (boreal lakes) Mine tailing ponds Deep clear lakes with increasing eutrophication (alpine lakes, East African lakes, Great Lakes) Shallow lakes with low transparency due to sediment resuspension (Lake Marken, Tropical lakes) WFD reporting based on GLaSS products 38

39. Case studies: example Lake Malawi

41. Mean monthly MERIS FR

42. Case studies: Mine tailing ponds Sol V.M., Peters S.W.M., Aiking H. - Toxic waste storage sites in EU countries - A preliminary risk inventory (download http://www. wwffreshwater.org). ISBN 90-5383- 656-X, Institute for Environmental Studies, Vrije Universiteit, Amsterdam, The Netherlands, 1999, 82 pp

43. Atmospheric correction of S2 and OLCI -Can we treat OLCI as MERIS and use the tools that are available? -How quickly will we be able to work with the atmo-corr 400 nm band as well? -Will S2 data come with the same ancillary data as MERIS and OLCI -Will Atmo-corr take the height dependent Rayleigh correction into account? -Is there a possible synergy between OLCI and S2 wrt atmo-corr? -Will the standard landmask be sufficient? -Is the adjacency effect relevant, should we correct for that? Are the tools sufficient? -How quickly will new tools be accessible to the users and through which route: BEAM, ODESA, dedicated services (MIP?) -How to organize the match-up validation given the revisiting frequencies

44. Lake water quality algorithms for S2 and OLCI -Can we build a sufficiently large dataset (through LIMNADES?!) to develop and test generic algorithms -Should that dataset contain just spectra and concentrations, or also (S)IOPs? -Can we collect sufficient data to do a sound validation of algorithms -If not, can we develop data-poor methods that at least confirm the applicability of algorithms -How to proceed towards new generic products (phytoplankton functional types, particle size distribution, fraction inorganic to organic matter, WFD relevant indicators) if large scale validation is inherently difficult

45. Expected achievements • Sentinel 2 and 3 data formats integrated into user-accessible tools • Generic tools for S2 and S3 processing available to user community (Atm. Correction, feature extraction, time series analysis, etc.) • Updated algorithms for inland water analysis (Chl-a, TSM, CDOM, PC etc) for S2 and S3 tested and validated • Test datasets of S2 and S3 (simulated, and hopefully real) available • Material from use cases available for education and training • Global user community informed about GLaSS products and actively using project tools, data and results 45

46. Ongoing and future cooperations • There is information and knowledge exchange between GLaSS and ESA-Biodiversity II (BC) and Globolakes (University of Stirling) • Possibilities for Future Cooperation in USA, Australia and China via the Advisory Board • GLaSS team is accepted as S3VT • Cooperation to be set up with new FP7 projects INFORM (VITO) and Sensyf (Deimos) • GLaSS in-situ data to go into the LIMNADES database • Close contact with GEO 46

47. Thanks for your attention!