Assessing the Potential of PlanetScope Imagery for Iron Oxide Detection in Antimony Exploration

The increasing demand for critical raw materials, such as antimony—a semimetal with strategic relevance in fire-retardant applications, electronic components, and national security—has made the identification of European sources essential for the European Union’s strategic autonomy. Remote sensing o...

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Main Authors: Douglas Santos, Joana Cardoso-Fernandes, Alexandre Lima, Ana Claúdia Teodoro
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Remote Sensing
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Online Access:https://www.mdpi.com/2072-4292/17/14/2511
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author Douglas Santos
Joana Cardoso-Fernandes
Alexandre Lima
Ana Claúdia Teodoro
author_facet Douglas Santos
Joana Cardoso-Fernandes
Alexandre Lima
Ana Claúdia Teodoro
author_sort Douglas Santos
collection DOAJ
description The increasing demand for critical raw materials, such as antimony—a semimetal with strategic relevance in fire-retardant applications, electronic components, and national security—has made the identification of European sources essential for the European Union’s strategic autonomy. Remote sensing offers a valuable tool for detecting alteration minerals associated with subsurface gold and antimony deposits that reach the surface. However, the coarse spatial resolution of the most freely available satellite data remains a limiting factor. The PlanetScope satellite constellation presents a promising low-cost alternative for the academic community, providing 3 m spatial resolution and eight spectral bands. In this study, we evaluated PlanetScope’s capacity to detect Fe<sup>3+</sup>-bearing iron oxides—key indicators of hydrothermal alteration—by applying targeted band ratios (BRs) in northern Portugal. A comparative analysis was conducted to validate its performance using established BRs from Sentinel-2, ASTER, and Landsat 9. The results were assessed through relative comparison methods, enabling both quantitative and qualitative evaluation of the spectral similarity among sensors. Spatial patterns were analyzed, and points of interest were identified and subsequently validated through fieldwork. Our findings demonstrate that PlanetScope is a viable option for mineral exploration applications, capable of detecting iron oxide anomalies associated with alteration zones while offering finer spatial detail than most freely accessible satellites.
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series Remote Sensing
spelling doaj-art-b2cb7cfbb9ff4b3dbf05fcb6a2bd78d72025-08-20T03:32:18ZengMDPI AGRemote Sensing2072-42922025-07-011714251110.3390/rs17142511Assessing the Potential of PlanetScope Imagery for Iron Oxide Detection in Antimony ExplorationDouglas Santos0Joana Cardoso-Fernandes1Alexandre Lima2Ana Claúdia Teodoro3Department of Geosciences, Environment and Spatial Planning, Faculty of Sciences, University of Porto, 4169-007 Porto, PortugalDepartment of Geosciences, Environment and Spatial Planning, Faculty of Sciences, University of Porto, 4169-007 Porto, PortugalDepartment of Geosciences, Environment and Spatial Planning, Faculty of Sciences, University of Porto, 4169-007 Porto, PortugalDepartment of Geosciences, Environment and Spatial Planning, Faculty of Sciences, University of Porto, 4169-007 Porto, PortugalThe increasing demand for critical raw materials, such as antimony—a semimetal with strategic relevance in fire-retardant applications, electronic components, and national security—has made the identification of European sources essential for the European Union’s strategic autonomy. Remote sensing offers a valuable tool for detecting alteration minerals associated with subsurface gold and antimony deposits that reach the surface. However, the coarse spatial resolution of the most freely available satellite data remains a limiting factor. The PlanetScope satellite constellation presents a promising low-cost alternative for the academic community, providing 3 m spatial resolution and eight spectral bands. In this study, we evaluated PlanetScope’s capacity to detect Fe<sup>3+</sup>-bearing iron oxides—key indicators of hydrothermal alteration—by applying targeted band ratios (BRs) in northern Portugal. A comparative analysis was conducted to validate its performance using established BRs from Sentinel-2, ASTER, and Landsat 9. The results were assessed through relative comparison methods, enabling both quantitative and qualitative evaluation of the spectral similarity among sensors. Spatial patterns were analyzed, and points of interest were identified and subsequently validated through fieldwork. Our findings demonstrate that PlanetScope is a viable option for mineral exploration applications, capable of detecting iron oxide anomalies associated with alteration zones while offering finer spatial detail than most freely accessible satellites.https://www.mdpi.com/2072-4292/17/14/2511antimonygoldband ratiomineral explorationsatellitecritical raw materials
spellingShingle Douglas Santos
Joana Cardoso-Fernandes
Alexandre Lima
Ana Claúdia Teodoro
Assessing the Potential of PlanetScope Imagery for Iron Oxide Detection in Antimony Exploration
Remote Sensing
antimony
gold
band ratio
mineral exploration
satellite
critical raw materials
title Assessing the Potential of PlanetScope Imagery for Iron Oxide Detection in Antimony Exploration
title_full Assessing the Potential of PlanetScope Imagery for Iron Oxide Detection in Antimony Exploration
title_fullStr Assessing the Potential of PlanetScope Imagery for Iron Oxide Detection in Antimony Exploration
title_full_unstemmed Assessing the Potential of PlanetScope Imagery for Iron Oxide Detection in Antimony Exploration
title_short Assessing the Potential of PlanetScope Imagery for Iron Oxide Detection in Antimony Exploration
title_sort assessing the potential of planetscope imagery for iron oxide detection in antimony exploration
topic antimony
gold
band ratio
mineral exploration
satellite
critical raw materials
url https://www.mdpi.com/2072-4292/17/14/2511
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