title: IDEAS-QA4EO WP-2650: S24ICOS
title: Web-based tool for validation of Sentinel-2 and Sentinel3 derived bio‐geophysical products against ICOS terrestrial ecosystems measurements
titleType: Subtitle
Creators: name: Cremer, Noelle
name: De Grandis, Erminia
name: Niro, Fabrizio
name: Papale, Dario
name: Nicolini, Giacomo
name: Sabbatini, Simone
Publisher: name: Zenodo
Year: 2023
Subjects: ICOS
Cal/Val
Sentinel-2
Sentinel-3
faPAR
LAI
IDEAS-QA4EO
QA4EO
Remote Sensing
Earth Observation
Multispectral
Validation

description: The Integrated Carbon Observation System, ICOS, is a pan­‐European research infrastructure for observing and understanding the greenhouse gas (GHG) balance of Europe. The major mission of ICOS is to integrate highly standardized networks from multiple domains, such as atmosphere, terrestrial ecosystems, oceans, and collect and make available standardised open data from more than 140 measurement stations across 14 European countries. 
Besides, as a science-based infrastructure, ICOS has been developed by addressing the Essential Climate Variables (ECVs) and in the terrestrial ecosystem domain provides both observations towards the ECV anthropogenic GHG fluxes mainly related to land use and biophysical parameters such as land surface albedo, leaf area index, aboveground biomass, and soil carbon.
The aim of this study is firstly to demonstrate that ICOS terrestrial ecosystems sites can serve as network for validation of Earth Observation products and then enhance our ability to validate satellite EO data in terms of spatial and temporal coverage. To this end, focusing on the current ESA optical imaging sensors, namely Sentinel-2 and Sentinel-3, the WP provides a web-based tool for validation of satellite‐derived biophysical products against in situ data, by identifying ways how to properly scale and compare the ground-based measurements with satellite measurements: the objective is to ensure a good representativeness of the validation dataset impacted both by an inner spatial heterogeneity and temporal variability of terrestrial surfaces and a different spatial and temporal sampling between the two dataset. 
In detail, the project will focus on the validation of a subset of radiation and vegetation parameters, including key terrestrial ECVs, namely: Fraction of absorbed photosynthetically active radiation (FAPAR) and Leaf Area Index (LAI). The Terrascope platform was selected from an assessment of existing cloud-based data services to guarantee an effective EO data access, a good data completeness and an easy interoperability.
description: D-1 Strategy and methodology used for validation of Sentinel-2 and Sentinel-3 derived bio‐geophysical products against ICOS terrestrial ecosystems measurements
Strategy and methodology are explained in the file S24ICOS ProjectDescription.pdf. The notebooks/tutorials found in the S24ICOS_terrascope folder (see [D-3]). Further documents include a list of variables of interest in S24ICOS_VarSynthesis.pdf and a list of possible improvements in data distribution for satellite cal/val update in S24ICOS_MeasurementSuggestions.pdf.
D-2 Prototype with first results
First results are shown in the S24ICOS_FirstResults.pdf presentation, the three prototypes can be found within the notebooks (see [D-3]).
D-3 Jupiter Notebooks in the selected cloud platform
For Terrascope users, the notebooks have been placed in a public folder /data/users/Public/noellemarie/S24ICOS and can be freely accessed. Further information on how to access and copy the data can be found here.
D-4 Tutorial material associated to the Notebooks
Tutorial material, code and notebooks can all be found in the S24ICOS_terrascope folder. Notebooks including tutorials are the following:

S24ICOS_terrascope /S24ICOS_Match-UpDatabase.ipynb
S24ICOS_terrascope /S24ICOS_SpatialRepresentation.ipynb
S24ICOS_terrascope /S24ICOS_Upscaling.ipynb
D-5 Input to reports, presentation to WS on main functionalities provided by the tool, papers, outreach material
Poster presentation at LPVE can be found in ICOS_POSTER_LPVE_23_CREMER.pdf.