@article{5bd7466181a4473d9ee003c1427f5b0c,
title = "An inter-comparison exercise of Sentinel-2 radiometric validations assessed by independent expert groups",
abstract = "Copernicus is the European Union's Earth Observation and Monitoring programme, delivering free access to operational and historical environmental data to support applications in a wide range of societal benefit areas. To allow meaningful long-term environmental monitoring and robust decision-making, it is essential to ensure that satellite-retrieved products are of high quality and consistency. This paper describes the outputs of an international workshop on the radiometric calibration validation of the Copernicus Sentinel-2A and Sentinel-2B Multi-Spectral Instrument. A wide range of vicarious methodologies have been applied independently and then compared per type of target. All methods agree on the good radiometric performance of both Sentinel-2A and Sentinel-2B with respect to the mission requirements as well as on evidence of a slight bias between the two instruments. Comparisons of all these results are discussed to highlight the benefits and advantages of the methods as well as to propose potential improvements either for the methods themselves and/or for the comparison exercise.",
keywords = "Expert groups, Inter-comparison, Radiometric validation, Sentinel-2, Vicarious methodologies",
author = "Nicolas Lamquin and Emma Woolliams and V{\'e}ronique Bruniquel and Ferran Gascon and Javier Gorro{\~n}o and Yves Govaerts and Vincent Leroy and Vincent Lonjou and Bahjat Alhammoud and Barsi, {Julia A.} and Czapla-Myers, {Jeffrey S.} and Joel McCorkel and Dennis Helder and Bruno Lafrance and Sebastien Clerc and Holben, {Brent N.}",
note = "Funding Information: This work, part of the S2RadVal project, was supported by the European Space Agency under Grant 4000116454/16/I-Sbo . Science Systems and Applications, Inc. work was performed under NASA contract NNG15HQ01C. The University of Arizona was funded by NASA Research Grants NNX16AH44G and NNX16AL25G , and USGS Cooperative Agreement G14AC00371. NPL received funding from the MetEOC-3 project from the EMPIR programme co-financed by participating states and from the European Union's Horizon 2020 Research and Innovation Framework Programme . Funding Information: The Gobabeb site is operated as an ESA-CNES site, with ESA supported by NPL. It has an automatic ground-based station comprising a CIMEL photometer on a 10?m mast (Marcq et al., 2018). This makes measurements for multiple viewing geometries, which are used to parameterise a site bidirectional reflectance distribution function (BRDF) model and to determine downwelling irradiance. The official RadCalNet product takes nadir-viewing measurements from this model, NPL performed a comparison of S2-MSI to the official RadCalNet product. The CNES analysis compared the S2-MSI reflectance to that simulated by the full model, as described in Revel et al. (2019).This work, part of the S2RadVal project, was supported by the European Space Agency under Grant 4000116454/16/I-Sbo. Science Systems and Applications, Inc. work was performed under NASA contract NNG15HQ01C. The University of Arizona was funded by NASA Research Grants NNX16AH44G and NNX16AL25G, and USGS Cooperative Agreement G14AC00371. NPL received funding from the MetEOC-3 project from the EMPIR programme co-financed by participating states and from the European Union's Horizon 2020 Research and Innovation Framework Programme. We would like to thank the following people involved in the production and distribution of AERONET-OC data: Giuseppe Zibordi (Venise, Gustav_Dalen_Tower, Galata_Platform, Gloria, Helsinki_Lighthouse sites), Sam Ahmed and Alex Gilerson (LISCO site), Hui Feng and Heidi M. Sosik (MVCO site), Dimitry Van der Zande (Thornton_C-power site), Burton Jones and Curtiss Davis (USC_SEAPRISM site), as well as Alan Weidemann, Bill Gibson, and Robert Arnone (WaveCIS_Site_CSI_6 site). Finally, we are grateful to three anonymous reviewers for providing very constructive comments that led to better organization and consolidation of this paper. Publisher Copyright: {\textcopyright} 2019 Elsevier Inc.",
year = "2019",
month = nov,
doi = "10.1016/j.rse.2019.111369",
language = "English (US)",
volume = "233",
journal = "Remote Sensing of Environment",
issn = "0034-4257",
publisher = "Elsevier Inc.",
}