LiDAR vs photogrammetry for mining
Photogrammetry reconstructs geometry from overlapping photographs; LiDAR measures it directly with light. Both produce a point cloud, and they fail in different places: photogrammetry where there is no texture, light or GPS, LiDAR almost nowhere a scanner can be taken.
On a lit, textured, open pit both work. On the steep shadowed face, the dark rock, the tailings beach and the whole of underground, only one does.
LiDAR or photogrammetry for mine surveying?
LiDAR wherever conditions are hard — steep faces, dark rock, no light, no GPS, all of underground; photogrammetry for fast coverage of a lit, textured pit.
How they compare
The criteria are what the mine needs, not what a camera or a laser can do in principle.
| LiDAR (Artec Jet / Ray II)Distance measured directly with a laser, from a tripod or on the move. | Drone photogrammetryGeometry reconstructed from overlapping photographs. | |
|---|---|---|
| How geometry is obtained | Measured: each point is a timed laser return | Reconstructed: matched image features triangulated |
| Accuracy | 1.9 mm at 10 m on a tripod; ±10–15 mm on the move; stated per range | Depends on GSD, overlap, control and texture; varies across the model |
| Steep, shadowed or textureless faces | Unaffected — no texture or light needed; the wall is measured | Weakest here — shadow, bare rock and repetition break the matching |
| Darkness and underground | Works in complete darkness and with no GPS, by SLAM | Needs light to photograph and GPS to fly; stops at the portal |
| Coverage speed on surface | Tripod stations of under two minutes; vehicle or drone coverage at ±15 mm | Fast: a whole pit in one flight, in daylight |
| Processing | Register, georeference, clean, export — hours, and the error is known | Hours to days of computation; accuracy varies and is checked at control |
| Choose this when | Choose this for walls, underground, dark or textureless ground, and any figure that has to be defended. | Choose this for fast surface coverage of a lit, textured pit where it is already in use. |
Many operations fly photogrammetry for the pit overview and scan the walls, the plant and everything underground. The scan is the reference the photogrammetry is checked against.
Why the pit wall is where it is decided
Photogrammetry is a matching problem: the software finds the same feature in many photographs and triangulates it. It works well on ground that is well lit, textured and varied — a dump top, a haul road, a stockyard in daylight. It works badly where the matching fails: a steep face in shadow, bare dark rock with little texture, wet surfaces, repetitive patterns, and anywhere the camera cannot see. Those are the pit walls, the highwall in the morning shadow and the face of a fresh blast — the surfaces the geotechnical and design teams care about most. A LiDAR scanner does not match anything; it measures the distance to the wall directly, at 1.9 mm at 10 m from a tripod, in shadow or in darkness, and the accuracy is the same on bare rock as on anything else.
Underground, the comparison ends: there is no light to photograph by and no GPS to fly by, and photogrammetry stops at the portal. Where photogrammetry keeps its place is the open, lit pit. A drone flight covers the whole site in an hour with equipment the mine already has, and for a weekly overview of the pit floor, dumps and roads that is hard to beat. The honest arrangement is the one many sites run: fly the overview, scan the walls and the plant, survey everything underground with LiDAR, and treat the scan as the reference the photogrammetry is checked against.
The figures behind the verdict
See a shadowed highwall measured from a tripod at 40 m where the photogrammetry model went soft, and the two overlaid — book a demo for your survey manager.
Book a demoWhat people ask when choosing
Can we keep our photogrammetry drone?
Yes, and most sites do. Fly the pit overview with it; scan the walls, the plant and the underground with LiDAR, and use the scan as the reference to check the photogrammetry model against at the faces.
Is photogrammetry accuracy really worse?
It is less predictable. On good ground with good control it can be very good; on a shadowed face it degrades and the model does not tell you by how much. LiDAR accuracy is a stated figure at a stated range, the same on every surface.
Does LiDAR work in dust and rain?
Heavy airborne dust and rain degrade any optical method, LiDAR included; the scan is timed for a clear window, which a two-minute station makes easy. Darkness, shadow and lack of texture — photogrammetry’s real problems — do not affect it at all.
Can LiDAR be flown too?
Yes — Jet mounts to a drone and, unlike a camera drone, navigates by SLAM without GPS and in the dark, planning its own path and avoiding wires as fine as 2 mm. That is how it flies a stope; on surface it covers dumps and pits at ±15 mm.
Other comparisons
Tell us how you map the pit today
Describe what is flown, how often and where the model lets you down. A mining specialist will come back with where LiDAR would take over and how the two would work together.