Mineral Exploration and Satellite Detection Methods

What satellite imagery for mineral exploration can see

An optical satellite measures sunlight reflected from the top few microns of whatever covers the ground. That sounds limiting, but many deposits leave a footprint at the surface. Hydrothermal fluids that formed a gold or copper deposit also altered the rock around it, producing clays, micas, iron oxides and carbonates that each reflect light in a characteristic way, especially in the shortwave infrared.

Geologists map those minerals with band ratios and spectral indices from Sentinel-2, Landsat and ASTER, and with hyperspectral sensors when the mineral needs narrow bands to tell apart. Radar adds structure: faults, folds and lineaments that controlled where fluids moved. Terrain models, thermal data and drainage patterns add more layers. Our guides to alteration mineral mapping and band ratio techniques show how the maps are made.

Can satellites scan underground?

No satellite takes a picture of rock hundreds of meters down. Optical and thermal sensors see only the surface. Radar penetrates a few centimeters in most soils, and somewhat more in very dry sand. So claims of “satellite underground scanning” need careful reading.

What satellites can do is infer what lies below from surface evidence: alteration halos, structures, subtle topography, vegetation stress and regional magnetic patterns from compilations such as EMAG2. That inference works best where the deposit or its alteration reaches near the surface. Detecting deep mineral deposits beyond 500 meters with no surface expression is a job for ground and airborne geophysics, such as magnetotellurics, induced polarization, gravity and seismic surveys, and in the end for drilling. Our article on satellite underground scanning goes into what is and isn’t possible.

Where each exploration method fits

Satellite work is the cheapest per square kilometer, so it usually comes first on a new license. Each later step costs more per unit of area and is aimed at a smaller target:

Our overviews of geophysical methods and exploration drilling cover the later stages.

Choosing a mineral deposit detection service

Providers of satellite-based mineral deposit detection vary a lot. These questions sort them quickly:

• Which sensors and datasets go into the analysis, and why those for your mineral?
• Are results delivered as ranked targets with confidence levels, or as one colored map?
• How have past targets been checked, and what share were confirmed on the ground or by drilling?
• Which file formats do you get, and will they open in your GIS or mining software?
• Does the provider describe the output as Exploration Targets, ahead of a JORC or NI 43-101 resource estimate?

For reference, our satellite mineral detection service uses eight sensor families, including optical, shortwave-infrared, radar, thermal, terrain, magnetic, hydrology and land-cover data, and adds hyperspectral imagery for minerals that need narrow bands. Reports rank targets with confidence tiers and come with KML, GeoTIFF and GeoJSON files, usually in under five days from a usable boundary. On engagements where clients tested the ranked zones, 90% were confirmed by ground or drill evidence. The results are Exploration Targets and never a substitute for a JORC or NI 43-101 resource estimate.

Working with the results in Farmonaut Mining Pro

Targets are only useful if your team can inspect them, compare them and plan fieldwork around them. Farmonaut Mining Pro is our browser-based software for that step, used by more than 100 mining businesses in over 25 countries. Its nine tools cover a 2D map, raster inspector, 3D viewer, zone table, block model, drillholes, mine plan, economics, and export and reports. There is also a 16-chapter video course on how to use Mining Pro, which is free to watch and runs about four hours.

Projects that move toward drilling often need more than a target map. Our Premium+ reports add drilling angles and depths, a 3D subsurface model, an economic block model, synthetic drillholes and a conceptual pit shell, with exports for Leapfrog, Vulcan, Surpac and Datamine, so the targets can sit alongside your own data in the software your geologists already use. If you have a license boundary ready, the mining query form is the quickest way to ask about it.