What is Laser Scanning, and what are the benefits?
For any kind of infrastructure project, data collection has always been a requirement for design and build. For the last 10 years, laser scanning has been an integral part of this process, being the key tool for the surveyor. With the adoption of BIM (Building Information Modelling), and the benefits Laser Scanning brings, this is now the standard for all types of surveys.
How Does It Work?
3D laser scanning emits millions of laser points. These points give an accurate point in space of whatever they reflected off. Laser scanning relies on line of sight, so with the latest scanners the skill is now within the methodology. This is to ensure the survey is complete and accurate.
When objects or existing site conditions are scanned, millions of data points are recorded (invisible to the human eye) and the result is an accurate depiction of the scanned site or object. This accurate depiction is called a point cloud and with the level of point density now so high, the data is photo realistic.
Point cloud data goes into a common reference system where it’s merged into a complete model. This process is called alignment or registration, and dozens of scans can quickly be stitched together. This process is now becoming automated with the new Leica scanner registering the data onsite as it scans.
Why Would You Need It?
The real question is why would you not need it. It is the most accurate and complete way to reality capture data. Three key benefits are Speed, Accuracy, and Consistency.
Value Added Datasets:
- Quick data turn around from site work to data delivery
- Real time checking of the data (scan data can be viewed in real time in the field)
- Massive increase in data available compared to conventional surveys
- Increased safety by using reflectorless survey techniques
- Scan data is used to validate other forms of survey quickly and efficiently
- High quality images, animations and visualisations can be created for reports and presentations
What are the uses of laser scanning ?
The use of scan data is wide and diverse.
- Archive Data – a snapshot in time for records (building sites or heritage buildings)
- Visualisations – of complex 3D structures, 3D models for design or sighting issues, rights to light or simply to impress a client and get the desired funding
- Highly Detailed surveys – 3D wireframe or 3D plans of complex beams, structures, buildings, elevations.
- Inaccessible areas – no direct access or health & safety risk areas.
- Projects with poorly defined or changeable scope
- Limited time to gather data or produce deliverables. A 3D point cloud model will be issued the next day if required.
- Monitoring change & movement
- Volumes and quantity surveying applications
- Creation of cross sections through tunnels and rock cuttings, allowing flexibility to create extra sections wherever required
- Reverse Engineering
- scanning for Building Information Models (BIM)
Avoid the urge to go for the cheapest bid !
Within any profession you pay for the experience, expertise, and confidence the business has a solid reputation that will mitigate risks and add value. However in a growing industry like #geospatial, some businesses will outbid others to simply gain a competitive advantage, over and above providing the client with quality work delivered on time.
Pay peanuts get monkeys
You must ensure the Survey company is in fact a survey company. Like UAV, many ‘one man bands’ are popping up offering a laser scanning service yet have zero or limited survey understanding and experience. Some key points to consider when procuring a supplier:
- Are they chartered or a member of a professional body such as the TSA?
- What similar projects have they done?
- Are they able to meet the specification?
- Do they have the correct insurance?
- Where will the data be stored for the next 7 years? Will it be secure? What happens if they go close down?
- Are they able to meet the programme?
- What back up resource do they have should someone go off sick or on holiday?
- Who can consult with you should you need further work or guidance?
- What other benefits can they offer you to add value?
Procuring a laser scan can be daunting to a non technical person. If procured through a professional survey company they will guide and advise you ensuring you get exactly what you need.
Severn Partnership offer a consultative approach to ensure this, offering advice and experience along the way. For further information please contact:
Steve Jones, Commercial Manager