Atmospheric Correction Inter-Comparison eXercise, ACIX-III Land: An Assessment of Atmospheric Correction Processors for EnMAP and PRISMA over Land
Year: 2025
Type: article
Abstract: Correcting atmospheric effects on hyperspectral optical satellite scenes is paramount to ensuring the accuracy of derived bio-geophysical products. The open-access benchmark Atmospheric Correction Inter-comparison eXercise (ACIX) was first initiated in 2016 and has now been extended to provide a comprehensive assessment of atmospheric processors of space-borne imaging spectroscopy missions (EnMAP and PRISMA) over land surfaces. The exercise contains 90 scenes, covering stations of the Aerosol Robotic Network (AERONET) for assessing aerosol optical depth (AOD) and water vapour (WV) retrievals, as well as stationary networks (RadCalNet and HYPERNETS) and ad hoc campaigns for surface reflectance (SR) validation. AOD, WV, and SR retrievals were assessed using accuracy, precision, and uncertainty metrics. For AOD retrieval, processors showed a range of uncertainties, with half showing overall uncertainties of <0.1 but going up to uncertainties of almost 0.4. WV retrievals showed consistent offsets for almost all processors, with uncertainty values between 0.171 and 0.875 g/cm2. Average uncertainties for SR retrievals depend on wavelength, processor, and sensor (uncertainties are slightly higher for PRISMA), showing average values between 0.02 and 0.04. Although results are biased towards a limited selection of ground measurements over arid regions with low AOD, this study shows a detailed analysis of similarities and differences of seven processors. This work provides critical insights for understanding the current capabilities and limitations of atmospheric correction algorithms for imaging spectroscopy, offering both a foundation for future improvements and a first practical guide to support users in selecting the most suitable processor for their application needs.
Source: Remote Sensing
DOI: 10.3390/rs17233790
Authors: Noelle Cremer, Kevin Alonso, Georgia Doxani, Adam Chlus, David R. Thompson, Philip Brodrick, Philip A. Townsend, Angelo Palombo, Federico Santini, Bo-Cai Gao, Feng Yin, Jorge Vicent Servera, Quinten Vanhellemont, Tobias Eckert, Paul Karlshöfer, Raquel de los Reyes, Weile Wang, Maximilian Brell, Aime Meygret, Kevin Ruddick, Agnieszka Bialek, Pieter De Vis, Ferran Gascon
Institutions: European Space Agency, European Space Research Institute, California Institute of Technology, Jet Propulsion Laboratory, University of Wisconsin–Madison, CNR-IMIOT – Consiglio Nazionale delle Ricerche - Istituto di Metodologie Integrate per l’Osservazione della Terra, National Research Council, United States Naval Research Laboratory, Naval Research Laboratory Remote Sensing Division, National Centre for Earth Observation, University College London, Magellium (France), Institute of Natural Sciences, Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR), Ames Research Center, Norsk Elektro Optikk (Norway), Centre National d'Études Spatiales, National Physical Laboratory
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,258
Awards: G1430523195, G434337789, G4937468798
OpenAlex ID: W4416501236