How high-grade gold detection by satellite pinpointed a small footprint with an outsized signal — 13 target zones at a weighted 1.77 g/t, ranked before a single drill hole.
Region: West African gold belt
Method: Multispectral + SAR + DEM
Profile: Compact / high-grade
This case study is anonymised. The concession name, licence holder, coordinates and precise location have been removed at the client’s request; only country-level context (West Africa) is retained. All quantities are satellite-derived Exploration-Target estimates — a conceptual screening output, not a Mineral Resource or Reserve under JORC, NI 43-101, S-K 1300 or SAMREC, and not a substitute for drilling.
Big footprints get the headlines, but explorers know that grade is king. A compact, high-tenor target can out-earn a sprawling low-grade one on a fraction of the tonnage — if you can find it and prove it quickly. This anonymised case study shows high-grade gold detection by satellite doing exactly that: identifying a small, tightly clustered target whose weighted grade of 1.77 g/t stands roughly three times above the low-grade district average, and ranking its 13 zones before any ground work.
Farmonaut processed the compact area of interest through its satellite mineral-detection pipeline and returned 13 ranked gold target zones, a conceptual grade-and-tonnage envelope and a synthetic drill-and-pit planning pack. For a high-grade prospect, that speed matters: the sooner a strong target is ranked and framed, the sooner it can be drilled and de-risked.
“13 zones, a weighted 1.77 g/t — quality, not just quantity, spotted from orbit.”
The challenge: prove a high-grade lead fast
Compact high-grade targets present a different problem from district-scale screens. The prize is concentrated, so the priority is to confirm tenor and geometry quickly before committing to a drill programme — and to be certain the signal is real rather than a surface artefact from old workings or barren alteration.
- ⚠ Small area, high stakes — a modest footprint can still be highly valuable if grade holds.
- ⚠ Signal authenticity — high surface readings must be cross-checked against multiple sensors to rule out false positives.
- ⚠ Speed to drill — a strong lead loses value the longer it sits untested.
- ⚠ Tight geometry — drill placement must respect a compact, clustered target rather than a broad corridor.
The brief: screen the target from orbit, confirm the anomaly across independent evidence lines, rank the zones and return a conceptual economic frame and drill geometry.
Satellite screening is not only for huge licences. On a compact high-grade lead its value is fast, multi-sensor confirmation — separating a genuine high-tenor target from a surface mirage before you mobilise a rig.
Have a high-grade lead to test? Get a satellite mineral-intelligence quote — send a polygon and target mineral and we handle the analysis.
How high-grade gold detection by satellite works
Gold itself is not visible from orbit, but the alteration minerals, iron staining, host rocks and structures that accompany gold systems are. Farmonaut fuses several public Earth-observation datasets to read those fingerprints and combine them into one prospectivity surface — and on a compact target, the multi-sensor cross-check is what turns a strong reading into a credible one.
| Data layer | Role in a high-grade gold screen |
|---|---|
| Multispectral optical | Iron-oxide and clay alteration; bare-earth and extraction signatures. |
| Shortwave infrared | Sericite / argillic alteration typical of hydrothermal gold. |
| Radar (SAR) | Structural fabric and roughness; cloud-independent confirmation. |
| Digital elevation model | Faults, lineaments and landform controlling fluid focus. |
| Surface & hydrology indices | Moisture and drainage context to reject noise and false positives. |
The layers are normalised and merged into a composite gold prospectivity index — a weighted blend of alteration, structure, host-rock and detectability sub-scores. Conceptually:
alteration ,
structure ,
host-rock ,
detectability
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→ per-pixel score → ranked anomaly zones
An anomaly must appear across several independent evidence lines to survive filtering, which is exactly the discipline a high-grade lead needs. Each surviving zone gets a per-pixel grade estimate, a signal-strength class and an Exploration-Target confidence class (Class A / B / C).
On a high-grade target, treat a Strong signal that also survives the false-positive-risk checks as your priority. A high reading alone is not enough — it is the multi-sensor agreement that makes it drill-worthy.
A cascade built to reject false positives
On a high-grade lead, the danger is not missing the target — it is being fooled by it. Old workings, exposed bedrock and disturbed ground can all throw a bright surface signal that looks like high tenor. The pipeline guards against this with a multi-filter cascade: broad favourability first, then alteration and iron-oxide signatures, then structural coincidence, then detectability and false-positive checks. A high reading only becomes a ranked target once it has survived every stage across independent sensors. That discipline is what lets a compact 13-zone cluster be presented as a credible target rather than a hopeful one.
Signal strength on a compact cluster
Each zone carries a signal-strength class — Strong, Moderate, Weak or Marginal — measuring how emphatically it stands out from its background. On a tightly clustered high-grade target, this pinpoints the core: the Strong zones define where the tenor concentrates and where the first holes should go, while lower classes map the halo around the core.
Risk flags before you commit a rig
Every zone is annotated with false-positive-risk flags that state why it might not be genuine. For a high-value drill decision this is the most important column in the table: a Strong, unflagged zone justifies mobilising quickly, while a Strong but heavily flagged zone earns a fast ground check first. Publishing the caveats is what makes a high-grade claim honest.
For a high-grade lead, the multi-sensor false-positive filter is the whole point. It is the difference between mobilising a rig onto a real target and onto a surface mirage.
See the platform: Farmonaut satellite-based mineral detection turns a polygon into heatmaps, ranked zones, depth ranges and indicative quantities.
Results: 13 ranked zones at 1.77 g/t
Across the compact AOI, the pipeline flagged and ranked 13 discrete gold target zones. Aggregated, the satellite-derived Exploration-Target envelope came to roughly 426 kg of contained gold (about 13,682 troy ounces) within an indicative host tonnage of ~0.70 million tonnes at a weighted grade of 1.77 g/t — the standout feature of this target. At USD 4,037/oz, that maps to an indicative in-situ gross value near USD 55 million, or about USD 44.7 million recoverable at an industry-standard 81% blended recovery.
These are conceptual, satellite-derived Exploration-Target figures, not a resource estimate. The 1.77 g/t weighted grade is modelled from remote sensing and, while notably higher than the low-grade district norm, must be confirmed by drilling. Treat the totals as a screening-stage envelope for prioritising a fast, focused drill test.
Target at a glance
| Metric | Satellite-derived estimate | Basis |
|---|---|---|
| Target zones ranked | 13 | Multi-evidence anomaly polygons |
| Contained gold (in-situ) | ~426 kg / 13,682 oz | Sum across all zones |
| Indicative host tonnage | ~0.70 million tonnes | Conceptual envelope |
| Weighted average grade | 1.77 g/t Au | Tonnage-weighted (high-grade) |
| Indicative gross value | ~USD 55 M | @ USD 4,037/oz spot |
| Indicative recoverable value | ~USD 44.7 M | @ 81% blended recovery |
| Confidence classes | Class A / B / C | Exploration-Target tiers |
What makes this target interesting is not its size but its tenor and compactness. A weighted grade near 1.77 g/t on a small footprint concentrates value into a tight cluster of zones — the kind of profile that can justify a fast, focused drill test rather than a sprawling regional programme. The 13 zones are ranked so the operator can lead with the strongest, most confidently detected targets.
Class A — drill-ready high-grade cores
Strong-signal zones that survive the multi-sensor and false-positive-risk checks — the highest-tenor, highest-confidence targets and the natural first holes.
Class B — validation targets
Moderate-signal zones or those with a risk flag or two. Worth quick ground-truthing before drilling to lock in the geometry.
Class C — pipeline / watchlist
Weaker or flagged zones retained for completeness — low near-term priority, but useful context around a compact cluster.
From anomalies to a drill plan
To make the ranking actionable, Farmonaut delivered a conceptual planning pack built from the satellite grade surface: a synthetic drillhole layout, a regularised block model, closed ore-body solids for the strongest zones, and a floating-cone pit outline with a conceptual schedule — scaled to a compact, high-grade geometry.
The drillholes, block model and pit are generated from the satellite grade surface, not physical drilling. They let a mine-planning team rehearse the full Leapfrog / Vulcan / Surpac / Datamine workflow on realistic geometry and decide where real holes should go. Every layer is labelled synthetic with Exploration-Target confidence codes — explicitly not Measured / Indicated / Inferred material.
The result is a tight, drill-ready scoping geometry: a small number of high-tenor zones, a grade surface, indicative depths and a conceptual pit — everything needed to design a focused drill test that could confirm a high-grade discovery quickly.
“A compact high-grade lead, confirmed across sensors and framed for drilling in days.”
Impact: time, cost and ESG
Even on a small target, the three-axis economic case holds — and speed matters even more when the prize is high-grade.
Time: a ranked target in days
Instead of a slow reconnaissance to confirm a lead, the satellite screen ranked the 13 zones and framed the economics in days, so a focused drill test could be planned immediately.
Cost: up to 80–85% cheaper at the front end
Multi-sensor confirmation from orbit avoids an expensive ground campaign just to decide whether a high reading is real. Front-end exploration cost falls by up to 80–85% versus ground-first validation.
A compact, high-grade, multi-sensor-confirmed target ranked in days is a strong, fundable narrative. High tenor on a small footprint can support attractive economics on modest tonnage — and the fast confirmation shortens the path to a drill-tested result.
ESG: minimal early footprint
The screening phase is entirely orbital, with no ground disturbance until a focused validation drill test begins — a light footprint for a high-value lead.
Confirming a high-grade lead from space means the first ground activity is a targeted drill test, not speculative trenching — less disturbance, less fuel, less community impact.
| Dimension | Traditional ground-first | Satellite-first screening |
|---|---|---|
| Time to ranked target | Weeks to months | Days |
| Early-stage cost | Full validation budget | Up to 80–85% lower |
| Ground disturbance | Trenches, tracks, sampling | None during screening |
| Signal confidence | Single-method reading | Multi-sensor cross-check |
| Output | Sample points | Ranked zones + grade surface + conceptual plan |
Why high-grade clusters form — and where screening fits
High-grade gold usually reflects a particularly efficient piece of geological plumbing. In orogenic and hydrothermal systems, gold concentrates where fluids were repeatedly focused and where pressure or chemistry changed abruptly — at structural intersections, dilational jogs and reactive host rocks. When those conditions coincide in a small area, the result is a compact, high-tenor cluster rather than a diffuse low-grade halo. That is the profile seen here: 13 zones tightly grouped at a weighted grade roughly three times the low-grade district norm. Because the controls are structural and alteration-related, they leave surface expressions a multi-sensor screen can detect and rank.
Reading the target through that model matters even more on a high-grade lead, because the prize is concentrated and the drill decision is expensive. Zones that sit on coincident structure and alteration are geologically coherent; isolated bright pixels are not. Ranking the cluster against the deposit model — and against the false-positive checks — is what turns an eye-catching grade number into a drillable target.
With high grade, resist the urge to drill the single brightest pixel. Drill the Strong, unflagged zone that also fits the structural model — that is where a compact high-grade core is most likely to be real.
Where satellite screening sits in the exploration lifecycle
Even — especially — on a high-value lead, screening front-loads the pipeline so the expensive stages start from confirmed ground:
- Screening (this stage) — satellite detection ranks the cluster and returns a grade surface and conceptual plan in days.
- Ground validation — fast mapping and geochemistry over the Class A core to confirm tenor and geometry.
- First-phase drilling — a focused drill test into the high-grade core, guided by the conceptual geometry.
- Resource definition — infill drilling toward a JORC / NI 43-101 Mineral Resource if the core responds.
- Study & development — scoping and feasibility work on confirmed resources.
Here the compactness is an advantage: a small, ranked, multi-sensor-confirmed cluster can move from screen to focused drill test faster than a sprawling district, shortening the path to a de-risked result.
A compact high-grade target confirmed across sensors and framed for drilling in days is one of the most capital-efficient early-stage stories in gold exploration — high potential value on modest tonnage, reached quickly.
What you actually receive
Even a compact target arrives as a complete, actionable package. For this study the deliverable set included, at minimum:
- 📊 A ranked anomaly inventory — all 13 zones with prospectivity score, signal-strength class, confidence class and false-positive-risk flags.
- 🗺 Prospectivity heatmaps and alteration overlays — full-resolution, georeferenced imagery behind the ranking, ready for any GIS.
- ⛰ A per-pixel grade surface and estimated depth ranges across the cluster.
- 🔧 A conceptual 3D and mine-planning pack — here on the order of 140 synthetic drill collars, a block model of roughly 88,000 blocks, closed ore-body solids for the strongest zones, and a floating-cone pit outline — exportable to Leapfrog Geo, Maptek Vulcan, GEOVIA Surpac and Datamine.
- 📄 A written geological interpretation tying the high-grade core to structure and alteration.
Everything is georeferenced, so it registers directly against the operator’s existing project coordinates and drill database.
The economic assumptions behind the numbers
The indicative values here rest on a short, stated set of industry-standard inputs: a gold price of USD 4,037 per troy ounce (the spot level at the time of analysis), an 81% blended metallurgical recovery, and grade and tonnage modelled per pixel from the satellite prospectivity surface. Contained gold is in-situ; recoverable value applies the recovery factor. No dilution, processing cost, royalty or discount rate is included — those come later. On a high-grade target the grade estimate is the number that most rewards early drilling confirmation, so treat the 1.77 g/t as a screening-stage indicator to be tested first, not a resource grade.
Banking a high satellite grade as proven. A modelled 1.77 g/t is a strong reason to drill, not a confirmed grade — the drill test is what converts a promising signal into a resource-quality number.
How to get this for your own site
Whether your target is a district or a compact high-grade lead, the workflow is the same.
- Send us your area of interest as coordinates, KML/KMZ or a polygon, plus country/region and target mineral(s).
- We select and acquire the data (multispectral or hyperspectral) and run the detection pipeline.
- You receive a premium mineral-intelligence report — heatmaps, ranked zones, depth ranges, indicative quantities and geological interpretation — typically in 5–20 business days.
- Add Premium+ TargetMax™ for optimal drill angles, 3D subsurface models and the conceptual planning pack.
Confirm your high-grade lead from space
Farmonaut screens your target from orbit and hands back ranked zones, a grade surface and a conceptual plan — georeferenced and drill-ready — in days.
Go 3D: our satellite-driven 3D mineral prospectivity mapping shows how ranked zones extend into conceptual subsurface models — the geometry behind this study’s synthetic pit.
Limitations you should know
Honest screening means being clear about the method’s limits — and on a high-grade lead those limits matter most. Remote sensing reads the surface and near-surface expression of a mineral system and infers the rest from terrain and structure; it does not see gold at depth directly. Thick cover, vegetation or laterite can mute or distort the surface signal, which is why detectability is scored and why some zones carry risk flags. The modelled 1.77 g/t weighted grade is exactly that — a model, calibrated for internally consistent ranking, not an assay. Real grades from drill core will differ, and the tightly clustered geometry means the payoff hinges on a relatively small number of holes hitting the core.
That is why the workflow deliberately pairs satellite screening with fast ground validation and a focused drill test. Satellite detection is a targeting and confirmation tool that narrows the search and orders the drilling; drilling is what turns a promising high-grade signal into a resource-quality number. The 13-zone inventory should be read as a rigorous, auditable reason to drill quickly — not as proof of a deposit.
On a compact high-grade target, use the risk flags to design your first few holes. Clearing the flagged uncertainties early is the fastest route to either confirming the core or walking away cheaply.
Frequently asked questions
Can satellites really flag a high-grade gold target?
Satellites detect the alteration, iron staining, host rocks and structures around gold systems, then rank them by prospectivity. A high, multi-sensor-confirmed signal flags a strong lead — but grade is only proven by drilling.
Is 1.77 g/t a confirmed grade?
No. It is a satellite-derived, modelled weighted grade for the target — notably higher than the low-grade district norm, but an Exploration-Target estimate that must be confirmed by drilling, not a resource grade.
Is satellite screening worth it for a small target?
Yes — arguably more so. On a compact high-grade lead the value is fast, cheap, multi-sensor confirmation before you mobilise a rig, which is exactly what protects a high-value drill decision.
How quickly can I get results?
Typically 5–20 business days depending on area and complexity — a compact target usually sits at the faster end.
Why is the location withheld?
At the client’s request, the concession name, licence holder and coordinates are removed to protect commercially sensitive ground. The geology, method and economics are shown in full; only the site identity is withheld.
What do I need to provide?
Your area of interest (coordinates, KML/KMZ or polygon), country/region and target mineral(s). Request a quote and we handle data selection and analysis.
How does satellite screening compare with airborne geophysics?
They are complementary. Airborne magnetic, radiometric and electromagnetic surveys are powerful but need aircraft mobilisation, permitting and real budget, and they typically run after a target is chosen. Satellite screening comes first, over any polygon, in days and far more cheaply — it is the wide-area filter that decides where deeper geophysics and drilling are justified. On a compact high-grade lead, the satellite screen confirms the target is real across sensors and frames the drill test; airborne or ground geophysics can then refine the core geometry before drilling.
Can you screen for minerals other than gold?
Yes — the same approach covers copper, lithium, manganese, silver and many other commodities, each with its own diagnostic alteration and host-rock signatures. The model is tuned to whichever target mineral you specify with your area of interest.
Glossary
- Grade (g/t)
- Grams of gold per tonne of rock — the key measure of ore quality. Higher grade means more gold per tonne mined and processed.
- High-grade target
- A prospect whose modelled grade sits well above the local norm, concentrating value into a smaller tonnage.
- Prospectivity index
- A composite per-pixel score blending alteration, structure, host-rock and detectability signals into a measure of gold potential.
- Exploration Target
- A conceptual early-stage estimate of potential quantity and grade — explicitly not a Mineral Resource or Reserve.
- Blended recovery
- The share of contained gold expected to be recovered in processing; 81% is used here as an industry-standard scoping assumption.
Disclaimer: This anonymised case study presents satellite-derived Exploration-Target estimates for screening and target-prioritisation purposes only. All quantities are conceptual, modelled from remote-sensing data, and are not a Mineral Resource or Ore Reserve under JORC, NI 43-101, S-K 1300 or SAMREC. Economic figures use a spot gold price of USD 4,037/oz and an 81% blended recovery assumption for scoping illustration only. Drilling and further study are required to confirm any mineralisation. Farmonaut provides mineral-intelligence analytics and is not a mineral producer, marketplace or regulatory body.
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