SLAM LiDAR: Ground-Based Indoor & Underground Mapping

Some spaces don’t have a sky. Basements, tunnels, underground utilities, multi-story interiors, mines, dense canopy: anywhere a drone can’t go and GPS can’t see. A SLAM scanner solves that. The operator walks through the space carrying a handheld, pole-mounted, or backpack-mounted LiDAR; the scanner uses Simultaneous Localization and Mapping to build its own coordinate system on the move, fusing laser returns with inertial data. No satellite signal required. The result is a measurable 3D model of an environment that aerial capture can’t reach.

When SLAM is the right tool

If the space is open and visible from the air, aerial LiDAR is faster and cheaper. If the space is inside a tank or vessel and your crew shouldn’t enter, that’s a confined-space drone job. SLAM ground-based scanning is the in-between tool: facility interiors, utility tunnels, parking decks, retail buildouts, industrial floors, library and museum scans, mine shafts. We pick the scanner type (handheld for cramped spaces, pole for over-counter or wall-mounted detail, backpack for long traverses) based on the room you have to work in.

What we deliver after a SLAM mission

• Registered point cloud in .LAS / .LAZ / .E57: tied to a site control network if you have one, or to local coordinates if you don’t.
• Walkable mesh for navigable interior review in a web viewer or 3D engine.
• Floor plans extracted from horizontal slices at any height you specify: slab, ceiling, mid-wall, mezzanine.
• Section views through any plane of the model for engineering review.
• BIM-ready exports for clash-checking workflows in Revit, Navisworks, AutoCAD, and similar.

The questions buyers ask first

• How does the accuracy compare to tripod laser scanning? Tripod terrestrial laser scanners are more accurate on tight tolerances; SLAM trades some accuracy for speed and the ability to cover floor area an order of magnitude faster. For most scan-to-BIM and as-built work, SLAM accuracy is sufficient. For metrology or precision fit-up, we recommend tripod.
• What about drift over long traverses? Drift is the known trade-off in SLAM. We control it with loop-closure passes (walking back through a known point) and by placing surveyed control markers in long corridors. The drift number on each project is reported with the deliverable.
• Can the data tie into our site control network? Yes. We register the point cloud to your existing control if you have one, or we set and survey targets to create one.
• Will it land in our software without reformatting? .E57 is the cleanest interchange format; .LAS / .LAZ work for point-cloud-aware tools; BIM-ready exports come in IFC or RVT-compatible formats. We confirm the destination software before mobilization.
• Lighting? SLAM doesn’t need ambient light to see; the LiDAR provides its own. Pitch-dark basements are fine.

Safety: the space governs, not the scanner

OSHA general-industry standards apply whenever we work inside an active facility. If the scan crosses into a permit-required confined space, your entry program governs the access: and depending on the hazard profile, a caged inspection drone may be the appropriate tool instead of sending a SLAM operator inside. We scope the safety arrangement before mobilization.

Who buys ground-based SLAM

AEC firms running scan-to-BIM on existing buildings, facility owners documenting plants for asset management, plant maintenance teams tracking change over time, heritage documentation projects (libraries, courthouses, historic landmarks), underground utility operators mapping vaults and tunnels, and mining operators capturing shaft and adit geometry.

How it’s priced

• Per-day on site is the dominant model: complexity (size, lighting, dust, registration density) drives the day count rather than a per-square-foot rate
• Processing line item covers registration, classification, floor-plan extraction, and any required deliverable transformations
• Mobilization fee for travel and any required after-hours or weekend access windows
• Bundled with a digital twin program? SLAM is one of the three sensors in our digital twin captures: there’s usually a meaningful discount when it’s part of a larger twin scope, not a standalone job