Introduction

Use this guide when the project requires geospatial orientation, and your surveyor has provided marked control points on site. You'll need at least three well-distributed control points with known coordinates. By the end, you'll have a dataset that aligns to project coordinates with minimal rework.

Note: For detailed instructions on how to capture control points with NavVis VLX refer to https://knowledge.navvis.com/docs/control-point-management

Planning the Scan

Why it matters

• Surveyed control points anchor and constrain the dataset, which helps reduce drift during capture and processing.

• Loop closures strengthen SLAM stability and help prevent local misalignment.

What to do

• Use at least three surveyed control points. Use more whenever possible for better accuracy.

• Distribute control points evenly across zones and levels. Do not concentrate them in one area.

• Plan the control point network before you scan.

• Revisit control points throughout the scan (early, mid-route, and near loop closures). Do not capture them all at the end of a long session.

• Build in frequent loop closures by crossing your path regularly, even when you use surveyed control points.

• Avoid layouts where control points fall on a single line. Use a geometry that spans the area or volume.

On-Site Guidelines

• Remain still while capturing a control point and move away only after confirming successful capture.

• Press the Control Point Button on the head of the device or the one below the screen to capture the control point.

• Keep a good distance and viewing angle. Include nearby flat surfaces (for example, wall and floor junctions).

• Ensure the device is stable and the laser scanners have a clear field of view when capturing the control point. The body must not obstruct the field of view.

• Stay behind the NavVis VLX and avoid leaning over or covering the front sensor.