Introduction

Use this guide when your scan path runs through corridors, landings, and staircases, areas where feature-poor geometry and foot traffic commonly cause SLAM errors. You'll need open access to the full route at low foot traffic times. By the end, you'll have clean, loop-closed coverage of walls, floors, doors, and every stair flight.

Corridors

Before attempting to scan a corridor, open all available doors. If the corridor has limited features, place additional objects, such as the device’s transportation box.

1. Start in an area with many features

1. Start in a lobby, junction, or larger room.

2. Slowly turn 360° so key details are visible to the laser scanners, including both corridor directions, nearby doors, ceiling, and floor.

2. Walk the corridor

1. Walk along the center line so both walls stay visible to the laser scanners.

2. Walk slightly sideways (about 30–45°) to widen what is visible to the laser scanners along the corridor. This allows the front laser to detect windows, door frames, and other corridor features, stabilizing SLAM.

3. Keep at least 50 cm from each wall.

4. If a corridor is narrower than 1 m and has few features (plain walls, no doors, no signs), SLAM-based errors are more likely.

3. Keep a steady pace

1. Walk at a steady, moderate pace.

2. Avoid sudden stops and sharp turns.

3. Keep the ceiling, walls, and floor visible to the laser scanners at the same time.

4. Scan in both directions

• Scan corridors in both directions to support loop closure and ensure complete coverage. Use one of these options:

  • Walk the corridor out and return, or

  • Walk it once, continue scanning beyond it, then return through the same corridor.

  • When you return, cross your earlier path at clear junctions to support loop closure.

On stairs, watch overhead clearance and move slower than on flat floors. Scan the staircase both up and down in the same dataset. This improves quality and reduces vertical mismatch in the point cloud. 

1. Capture context at the stairs

1. Start on a landing or in a corridor near the stairs.

2. Turn 360° so the landing, stair opening, nearby walls, and ceiling are visible to the laser scanners.

2. Scan going down

1. Focus on footing.

2. Keep one hand ready for the handrail.

3. Walk slowly and avoid quick turns, especially on narrow stairs.

4. At each landing, turn 360° to capture as much geometry as possible and also to detect the connection to the corridor (or next flight of stairs).

5. Capture panoramas at the bottom, middle, and top of the staircase.

3. Scan going up

1. Face the direction of travel.

2. Take short, even steps.

3. Move slowly and avoid sudden direction changes.

4. At each landing, turn 360° to capture maximum geometry and detect the connection to the corridor or next flight of stairs.

5. Capture panoramas at the bottom, middle, and top of the staircase.

4. Scan complex stair shapes

Use extra care on L-shaped, U-shaped, and spiral staircases.

• Treat each flight as a short segment.

• On every landing, slow down and ensure the full landing area is visible to the laser scanners.

• On spiral stairs, move especially slowly and keep a consistent distance from the center of the stair well. Focus the front laser scanner on the steps of the staircase, so it can detect the changing geometry.

• Keep the inner and outer railings (and any central column) visible to the laser scanners.

5. Choose a safe stopping point

End the scan on a landing or in a corridor, not mid-stair, unless you must stop there for safety.

On-Site Quality Checks

If there are still areas of the scan area not covered, tilt the device exposing the area to the laser scanners. Check the Quality Map.
Knowledge base: For detailed information refer to Quality Map Checklist

Post-Processing Quality Checks

Use NavVis IVION Processing to review the Quality Report for the dataset.

1. Check continuity

• Confirm corridor walls are straight and parallel, without sudden bends or twists.

• Confirm repeated features (for example, door frames) align consistently along the corridor.

• Confirm each set of stairs connects cleanly to the landing, and each landing connects to the correct corridor.

• Look for inaccuracies of the height of the steps, duplicate (“ghost”) surfaces, or sideways skewing or offsets.

• If you have a floor plan, spot-check that key junctions and stair connections match expected positions.

• In the Quality Report, check SLAM quality along the trajectory, especially in long corridors and stair sections. Compare with control points or reference measurements when available.

2. Check alignment with neighboring datasets

Verify that the dataset aligns well with neighboring datasets. Alignment should be accurate if scanning and processing were done correctly.

3. Plan a targeted rescan (if needed)

Plan a short follow-up scan that focuses on the affected junctions, landings, or stair sections. During this re-scan, move slowly and use clear connections (for example, landings and junctions) to strengthen loop closure.