How each method works
- SLAM — a LiDAR measures distances directly while the device tracks its motion; works in any light.
- Photogrammetry — software reconstructs 3D from many overlapping photos; needs good light and texture.
- Terrestrial laser scanning — a tripod laser scans precise points from fixed stations.
Three-way comparison
| SLAM | Photogrammetry | TLS | |
|---|---|---|---|
| Accuracy | 1–5 cm | 1–5 cm | 1–6 mm |
| Speed | Very fast | Fast (open areas) | Slow |
| Needs light | No | Yes | No |
| Best for | Interiors, mines, as-built | Roofs, terrain, stockpiles | High-precision detail |
Choose by scenario
Indoors, underground or in poor light, SLAM is the clear pick. For large open outdoor areas, roofs and terrain, drone photogrammetry covers ground fastest — see our drone surveying guide. When you need millimetres, use a terrestrial laser scanner.
Combining methods
Real projects mix them: a drone photogrammetry model of the roof and grounds, a SLAM walk of the interior, and a TLS scan of the few high-precision details — all georeferenced to shared control for one coherent deliverable.
Häufige Fragen
Is SLAM more accurate than photogrammetry?
They are broadly similar — both typically reach 1–5 cm. The real difference is conditions: SLAM works in any light and indoors, while photogrammetry needs good light and texture but adds high-quality colour.
SLAM or photogrammetry for interiors?
SLAM, almost always. It works in low light, captures continuously as you walk, and does not depend on texture — ideal for indoor as-built and BIM. Photogrammetry struggles indoors.
When should I use photogrammetry instead of SLAM?
For large open outdoor areas — roofs, terrain, stockpiles — drone photogrammetry covers ground faster and adds excellent colour, while reaching similar centimetre accuracy.