How to Prepare Your Site for Laser Scanning

Key Considerations Before Authorising a Laser Scanning Project

Laser scanning offers huge benefits in terms of speed, safety, and data accuracy. But before signing off on a survey, it’s important to pause and consider a few practicalities that can significantly affect the outcome, cost, and long-term usability of your scan data.

What Is Laser Scanning?

3D laser scanning is a line-of-sight method that captures everything within 360° of the scanner’s position. A typical scan captures two datasets:

1. Point Cloud Data – Millions of spatially accurate X, Y, Z points, including intensity values and surface normals.
2. Panoramic Images – High-resolution site photography, either in colour or black and white.

Each scan position can take anywhere from 1 minute to 3 hours, depending on the level of detail and range required.

What to Think About Before a Laser Survey

1. Survey More Than Just the Immediate Subject

It’s often more cost-effective to scan a larger area than just the object or space you’re interested in. Once the scanning team is mobilised and the equipment is set up, additional coverage may not add much to the overall cost—but it adds long-term value for future projects.

2. Prepare the Site

• Clear obstacles where possible: skips, scaffold, hoses, or people
• Avoid active works, steam leaks, and heavy equipment movement
• If outdoors, consider weather: rain and wind can distort scan accuracy, especially on reflective or moving surfaces

Even if your scanner is IP-rated, raindrops and surface water introduce noise and artefacts into the data.

📷 Image reference: Excessive point cloud noise due to site obstructions

Colour vs Black & White Scans

If your survey includes panoramic images, you’ll be given a choice between colour or black-and-white photography:

• Colour: Useful for virtual tours and visually rich reporting
• Black & white: Sharper in poor lighting conditions, and quicker to capture

Choosing colour can add time to each scan, which scales up quickly on large projects and affects cost.

📷 Image reference: Colour vs intensity value comparison in point cloud data

Post-Processing: What Happens After the Scan?

After site work is complete, the scan data undergoes processing and registration, which includes:

• Stray point filtering
• Range trimming (to improve accuracy)
• Noise and edge artefact removal

📷 Image reference: Point cloud before and after clean-up

Understanding Scan Deviation

People often talk about scanner accuracy (e.g., ±1mm), but deviation between multiple scans is just as important. Scanners are moved around the site to capture full coverage, and every movement introduces registration variance.

If not properly managed, this can lead to:

• Misaligned geometry
• Gaps or overlaps in point clouds
• Reduced confidence in downstream deliverables

Always request a deviation report after the scan—it should clearly show the average and maximum registration variance across the dataset.

📷 Image reference: Poorly registered point cloud causing geometry distortion

Who Owns the Scan Data?

Before commissioning the survey, clarify:

• That you, the client, will own the scan data
• That you will receive:
  • Registered point cloud in an editable format (e.g., E57, RCP, LAS)
  • A RAW copy of the dataset
  • Any supporting deliverables, such as models or panoramic tours

This is particularly important if you plan to use the data for future work or to support virtual site access platforms.

Final Thoughts

Laser scanning is a powerful tool—but only when the process is well thought out. By asking the right questions and preparing the site properly, you maximise the value of your investment and ensure your team can trust the data long after the scan is complete.