A 3D laser scan survey is typically the first step for an as-built project, providing highly accurate data that serves as the foundation for design, documentation, or modification work. At Offset, we take a tailored approach to ensure that every aspect of your site’s requirements is carefully considered.

Understanding Your Needs

We begin by estimating the scope of your project. This includes evaluating:

• Site-specific requirements: Any unique conditions or regulations that need to be considered.
• Size and complexity: The overall area to be scanned, including any congested or hard-to-reach spaces.
• Site access: How we will access the site, including safety protocols.
• Project goals: What you aim to achieve with the captured data, whether it’s detailed modelling, documentation, or planning.

We’ll work closely with you to discuss your specific needs and outline the factors that may influence the cost of the survey.

Preparing for the Survey

Once you engage our team for a survey, we begin preparations. This includes developing a comprehensive risk assessment and method statement, ensuring all safety and operational concerns are accounted for based on your site’s unique demands.

On-Site Operations

After arriving on-site and completing any necessary inductions, our expert engineers will:

• Review the area to be scanned.
• Discuss any operational factors that could affect the scanning process for the day.

For more complex projects, we may establish a survey control network using a total station. This step isn’t always required and depends on the project’s specific needs. Our specialists will determine the most effective solution to deliver the best results for your project.

Choosing the Right Technology

Every site has its own challenges, choosing the right scanning equipment is crucial. Depending on the project’s demands, we utilise a range of scanners, including:

• Hand-held scanners: Ideal for tight spaces or intricate details.
• Tripod-mounted scanners: Providing highly detailed scans over larger areas.

Our team will select the best technology for your project, ensuring precise and reliable data capture every time.

Setting Up the Equipment

Once on-site, the laser scanner is securely mounted on a tripod or mobile platform, ensuring it remains stable for effective operation. For larger sites, such as industrial plants or construction sites, multiple scanning positions are planned to cover the area from various angles, providing complete data capture.

We may establish reference points, also called survey control points, either pre-existing or created on-site using traditional surveying equipment like total stations. These fixed markers ensure all scans are properly aligned during post-processing for accurate results.

Data Capture

During a laser scan survey, several key factors must be considered to ensure accurate data capture. Line of sight is crucial, as the laser needs an unobstructed view to measure surfaces effectively; this means the scanner may need to be moved to different locations around the site to avoid blind spots. Coverage is another important aspect, requiring multiple scans from various angles to create a complete model without gaps. The resolution of the scan is adjusted based on the project’s needs—higher resolution captures finer details but takes more time. In some cases, colour data is also collected, adding a visual layer to the 3D model which is a great addition to manyapplications including architecture or heritage projects, providing more context and detail.

Real-Time Monitoring

During the data capture, our surveyors monitor progress in real time using a connected tablets or laptop. This allows us to ensure the quality and completeness of the point cloud. If any sections are missed or if distortions occur due to environmental conditions (such as reflections or movement), the team can quickly adjust and re-scan the affected areas.

Post-Scan Checks

After the scanning is completed, an initial review of the data is typically done on-site. This ensures that no critical areas were missed and that the data is consistent. Conducting this review immediately helps avoid the need for costly return visits to re-scan missed sections.

Key validation checks include:

• Point cloud completeness: Verifying that all important areas are covered without significant gaps.
• Control point accuracy: Ensuring that the scans align correctly using the established control points.
• Environmental factors: Confirming that moving objects (such as people or vehicles) or environmental conditions didn’t negatively impact the data.