When people think about laser scanning, they usually picture the scanner itself sitting on a tripod capturing millions of measurements. But scanning is only one element of the project
Long before anyone steps onto site a significant amount of planning takes place to ensure the survey is carried out safely, efficiently and delivers exactly the information the client needs. Spending time planning beforehand helps reduce delays, avoid unnecessary revisits and ensures the final deliverables are fit for purpose.
Understanding the Project
Every project starts with a conversation.
Before we can recommend a survey solution, we need to understand what the client is trying to achieve. The same building, site or asset can be scanned in several different ways depending on the intended outcome.
Questions we typically ask include:
- What is the end goal of the project?
- Will the data be used for design, fabrication or asset management?
- Do you require a point cloud, 3D model or 2D drawings?
- What level of accuracy is required?
- Which areas or elements of interest need to be captured?
These discussions help us determine the most appropriate survey methodology before the project begins.
Existing Information
One of the first things we ask for is any existing information about the site.
This might include:
- Existing CAD drawings
- Site layouts
- P&IDs
- Presence of On-Site Coordinated System
- General Arrangement drawings
- Previous surveys
- Photographs
- Drone imagery
- Google Earth Imagery
Although these documents aren’t always accurate they provide valuable context and help us plan the survey more effectively. Sometimes they’re incredibly useful. Sometimes they’re decades out of date.
Planning Around Site Constraints
No two sites are the same. Industrial facilities are often live environments with ongoing operations, restricted access areas and safety requirements that need to be considered before arriving on site.
Some common challenges include:
- Restricted access to certain areas
- Working around operational equipment
- Shutdown windows
- Confined spaces
- Working at height
- Permit requirements
- High pedestrian or vehicle traffic
- Restrictions around ATEX zones and using Electrical Equipment on site
Understanding these constraints in advance allows us to plan the survey around the site’s operations rather than disrupting them.
Choosing the Right Equipment
Every survey is different and depending on the project we may require things such as:
- Terrestrial laser scanners
- Mobile mapping units
- GNSS/GPS equipment
- Total stations
- Survey control targets
- Telescopic tripods
- Inverted scanning rig
- Additional lighting
- PPE specific to the site
Selecting the right equipment beforehand means we’re prepared for the conditions we’ll encounter.
Survey Control and Accuracy
Accuracy doesn’t happen by accident.
If the project requires scans to align with an existing coordinate system, we’ll establish survey control before scanning begins. This allows all captured data to be accurately positioned within the client’s coordinate framework. Whether that be to a known control system inherent to the site, or a globally coordinated system.
For many engineering projects this step is essential for ensuring the produced datasets tie in with existing records and allows all future design work to align correctly with existing infrastructure.
Preparing for the Unexpected
No matter how much planning takes place, unexpected situations still arise. Equipment may be temporarily inaccessible, areas may become unavailable, weather may affect external surveys, or operational priorities can change with very little notice.
The key is having a flexible survey plan and enough experience to adapt without compromising the quality of the final deliverables.
Good Planning Saves Time
Laser scanning isn’t just about collecting data, it’s about collecting the right data and ensuring the quality of that data is suitable for the final use case. Our scanning engineers are also design engineers, which means our scanning activities are always approached from a design perspective. As if we would need to utilise the output ourselves.
A well-planned survey reduces time on site, improves accuracy and ensures clients receive the information they can confidently use for design and decision making. As a by-product a carefully orchestrated visit to site minimises exposure to potentially hazardous environments for not just our scanning crew but for other engineers working on the project.
In our next article we’ll take you onto site and look at what happens during a day of laser scanning.