From the Sky to Soil

S34I was a 30-month European project, started in January 2023, researching and developing new data-driven methods to analyse Earth Observation (EO) data, supporting systematic mineral exploration and continuous monitoring of extraction, closure, and post-closure activities, with the aim of increasing European knowledge and autonomy in raw materials resources. Copernicus and other satellite sensors (optical and radar) were exploited, while other sensing methods, such as airborne and low-altitude platforms, ground-based techniques, and fieldwork, were applied for calibration, validation, or to complement Copernicus data. The innovative EO-based products/services developed provide new and more accurate mineral mapping/exploration, environmental and mine monitoring, and mine safety across the different phases of the mine life cycle. Ultimately, S34I provided 50 new open datasets, 20 new methods to analyse EO data using Artificial Intelligence (AI) at different phases of the mining life cycle, nine new prototype EO-based services with 22 products tailored for mining stakeholders, one research and innovation agenda on EO for mining, and a set of recommendations for better policy and guidelines for EO uptake by the mining industry.

The importance of sourcing critical raw materials (CRMs) within the EU has been highlighted by the adoption of the Critical Raw Materials Act in 2024, strengthening the need to enhance the sustainability and safety of extractive activities. This underscores the urgency of ensuring that extractive activities align with EU sustainability and safety directives. The S34I project addresses critical challenges facing the European raw materials sector. At the same time, mining activities are increasingly scrutinised due to their environmental impacts, including land degradation, water contamination, and greenhouse gas emissions. These concerns often lead to low public approval and delays in project development. Another key challenge lies in the fragmented nature of data used in the mining lifecycle. Traditional exploration and monitoring approaches rely on limited, site-specific datasets that are not easily integrated, resulting in inefficiencies and uncertainty in decision-making. Despite these challenges, significant opportunities emerge from advances in EO and digital technologies. The availability of large-scale, continuous and free satellite data, combined with AI and data analytics, enables a shift toward more efficient, transparent, and sustainable mining practices. This could strengthen Europe’s strategic autonomy while supporting the transition to a greener, more digitally enabled economy.

During the exploration phase, EO data were used to identify mineral signatures and geological structures. When combined with existing geological data, this enables more accurate and less invasive identification of potential deposits, reducing both costs and environmental disturbance. Two pilot study areas were selected: one in Aramo, Spain, where the main objective was to improve mapping potential CRM target areas, such as Cobalt and Nickel, across both the exploration area and old mining waste deposits. The other pilot was in the Rias Baixas, Spain, where the main objective was to examine probable placer mineral deposits in the shallow waters of the Vigo estuary and to ascertain the potential of EO techniques for scrutinising or making decisions during the mineral exploration phase in coastal zones and shallow waters.

In the active mining phase, EO technologies support continuous monitoring of operations and safety conditions. Techniques such as ground deformation analysis provide near real-time insights into potential risks. In this phase, another pilot was used, located in Gummern, Austria. The main objective of this site was to demonstrate continuous monitoring of CRM extraction using ground instability maps, mineral stockpile volume estimation, and improved volumetric maps of mining waste deposits.

In the closure and post-mining phase, EO data plays a crucial role in long-term monitoring. For that, we selected three pilots. In Lausitz (Germany) and Outukumpu (Finland), the potential of free and commercial remote sensing datasets, including Sentinel-2, WorldView-3, and UAV imagery, was evaluated for large-scale, pixel-level mapping of AMD (Acid Mine Drainage). Two representative areas in the post-mining landscape of Lausitz were selected, covering post-mining lakes with varying AMD levels. In Outukumpu, expert manual validation was conducted, and water quality parameters were obtained through. Aijala’s mine (Finland) closed its operations in 1961 and experienced instability problems in 2017, when a tunnel collapsed in the southern area. The same approach (SAR data and INSAR techniques) were used to produce ground instability maps at the Gummern mine (active mine) was applied here to detect subsidence.

S34I developed and deployed a portfolio of EO-based data products, primarily leveraging satellite data (mainly from the Copernicus Programme), complemented by airborne, UAV, and in-situ sources. Mineral prospectivity and geological mapping products are mainly derived from multispectral and hyperspectral satellite imagery, enabling the identification of mineral signatures and geological structures while providing spatial probability maps for resource exploration (Fig. 1 and Fig. 2).

Ground deformation monitoring (InSAR products) is based on radar satellite data such as Sentinel-1, enabling the detection of millimetre-scale surface displacement over time (Fig. 3).

A key innovation of S34I is the fusion of EO data with complementary inputs, including geological datasets, in-situ sensor measurements, historical mining and environmental records, and operational data from mining companies. This integration enables multi-dimensional analysis, improving the reliability and usability of EO-derived information. The deployed EO products transform raw satellite data into actionable information, reducing uncertainty by combining multiple data sources, enabling near real-time insights through automated processing, and improving accessibility and transparency with user-friendly visualizations and open data access where possible. Through these EO data products, S34I delivers reliable and harmonised datasets (products and services) for stakeholders across the mining lifecycle, provides decision-ready information tailored to operational, environmental, and regulatory needs, enhances situational awareness through continuous monitoring, and promotes greater transparency, supporting trust among industry, regulators, and society.

The S34I project relies on a combination of EO data and complementary datasets to support decision-making across the mining lifecycle. These datasets provide multi-scale, multi-temporal, and multi-source observations, enabling a comprehensive understanding of geological conditions, operational activities, and environmental impacts.

Satellite EO data is primarily sourced from the Copernicus Programme, but also from other missions. Optical imagery (multispectral and hyperspectral) supports mineral prospectivity mapping, land cover classification, and environmental monitoring.

SAR data (and InSAR techniques) enable continuous monitoring of ground stability, subsidence, and infrastructure risks, independent of weather or daylight conditions (Fig. 4).

High-resolution aerial imagery (hyperspectral data) and drone-based surveys provide higher spatial resolution data for targeted analysis and calibration of satellite observations. Underwater Hyperspectral Imagery (UHI) data collected using a Remotely Operated Vehicle (ROV) were also used from underwater surveys at the shallow-water pilot site (Fig. 5).

Ground-based sensors and field surveys for sampling data (soil, water, geological samples) ensure accuracy and calibration of EO-derived products and support detailed environmental assessments. Also, existing geological maps and surveys support mineral exploration by integrating EO data with established geological knowledge.

S34I combines these datasets within integrated digital platforms, where EO data is fused with other inputs using advanced analytics and artificial intelligence. Geoportal (geo.s34i.eu) is a geospatial repository which stores and visually displays the spatial data generated under the scope of S34I, available as maps, and also stores significant datasets (Fig. 6). A geospatial processing infrastructure based on CREODIAS was also developed, to host advanced EO derived methods and AI based models prototyping to support the technical experimentation, and pilot validations/demonstrations for the pilot use cases.

S34I has demonstrated that integrating EO data with in-situ measurements and advanced algorithms can transform how mining activities are planned, monitored, and managed by improving exploration efficiency, enabling continuous environmental monitoring, enhancing safety and risk management, increasing transparency and accountability, and integrating fragmented data into unified, evidence-based decision-making systems.

The impacts of S34I extend across multiple stakeholder groups, delivering both direct and indirect benefits by improving safety and operational awareness for the mining workforce, enhancing environmental protection and transparency for local communities, providing reliable and efficient monitoring tools for public authorities and regulators, enabling more cost-effective and sustainable practices for industry, supporting better risk assessment and environmental, social, and governance alignment for investors, and contributing to supply security, sustainability, and the green and digital transition for wider society and the European Union.

S34I also contributes to a shift toward a more sustainable and socially responsible mining sector by promoting environmental stewardship through continuous monitoring, supporting evidence-based governance with transparent data, enhancing public trust through accessible information and enabling long-term resilience in raw material supply chains. By aligning technological innovation with societal needs, S34I demonstrates how EO can play a central role in building a more sustainable, resilient, and trusted raw materials sector.

Effective implementation of EO technologies depends on efficient multi-actor collaboration supported by clear objectives, well-defined needs, and detailed execution planning. It is essential to foster collaboration between entities with diverse interests (public, private, and academic) to continuously analyse and optimise current methodologies.