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ORIGINAL RESEARCH article
Front. Remote Sens.
Sec. Multi- and Hyper-Spectral Imaging
Volume 5 - 2024 |
doi: 10.3389/frsen.2024.1323998
This article is part of the Research Topic Optical Radiometry and Satellite Validation View all 22 articles
Feasibility of Satellite Vicarious Calibration using HYPERNETS Surface Reflectances from Gobabeb and Princess Elisabeth Antarctica Sites
Provisionally accepted- 1 National Physical Laboratory, Teddington, United Kingdom
- 2 Royal Belgian Institute of Natural Sciences, Brussels, Belgium
The HYPERNETS project developed a new hyperspectral radiometer (HYPSTAR®) integrated in automated networks of water (WATERHYPERNET) and land (LANDHYPERNET) bidirectional reflectance measurements for satellite validation. In this paper, the feasibility of using LANDHYPERNET surface reflectance data for vicarious calibration of multispectral (Sentinel-2 and Landsat 8/9) and hyperspectral (PRISMA) satellites is studied. The pipeline to process bottom of atmosphere (BOA) surface reflectance HYPERNETS data to band-integrated top of atmosphere (TOA) reflectances and compare them to satellite observations is detailed. Two LANDHYPERNET sites are considered in this study: the Gobabeb HYPERNETS site in Namibia (GHNA) and Princess Elizabeth Base in Antarctica (PEAN). 36 near-simultaneous match-ups within 1 hour are found where HYPERNETS and satellite data pass all quality checks. For the Gobabeb HYPERNETS site, agreement to within 5% is found with Sentinel-2 and Landsat 8/9. The differences with PRISMA are smaller than 10%. For the HYPERNETS Antarctica site, there are also a number of match-ups with good agreement to within 5% for Landsat 8/9. The majority show notable disagreement, i.e. HYPERNETS being over 10% different compared to satellite. This is due to small-scale irregularities in the wind-blown snow surface, and their shadows cast by the low sun. A study comparing the HYPERNETS measurements against a bidirectional reflectance distribution function (BRDF) model is recommended. Overall, we confirm data from radiometrically stable HYPERNETS sites with sufficient spatial and angular homogeneity can successfully be used for vicarious calibration purposes.
Keywords: Hypernets, hyperspectral, Validation, surface reflectance, uncertainty, Fiducial reference measurements, Earth Observation, Vicarious calibration
Received: 18 Oct 2023; Accepted: 16 May 2024.
Copyright: © 2024 De Vis, Howes, Vanhellemont, Bialek, Morris, Sinclair and Ruddick. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Pieter De Vis, National Physical Laboratory, Teddington, United Kingdom
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