3D Laser Scanning
3D Laser Scanning
3D Laser Scanning or LIDAR (Light Detection and Ranging) is the process of shining a reflectorless laser line over a surface in order to collect 3-dimensional data. The surface data is captured by a camera sensor mounted in the laser scanner which records accurate dense 3D points in space. The 3D survey points collected combine together to form a point cloud that represent the surface surveyed.
Mobile Mapping the Highways – Shrewsbury Town Centre
Point clouds can be viewed in multi hue colours (based on signal intensity return) or true colour from a digital camera. This technique provides a solution for the rapid surveying of inaccessible surfaces or complex geometrical details. The data can be linked in 3D to your site grid and matched seamlessly with topographical survey plans, elevations and & sections.
Follow these links to review some case studies, or watch this video to see ‘how laser scanning works’!
Laser scanning covers a number of techniques:
Close range: Sub ‘mm’ small objects or highly detailed surfaces observed from less than 0.5m away
Terrestrial: Ranges from 20m to 2km depending on the equipment, accuracy from 3mm to 100mm
Airborne: Usually helicopter based covering large areas to a lesser accuracy.
We utilise terrestrial phase based (HDS 6100), time of flight (HDS Scanstation) and Kinematic (helical) trolley based (Amberg) scanners to allow our surveyors to find the best, most productive solution to a given survey problem.
What are the benefits of scanning ?
Laser surveying helps avoid assumptions, generalisations, errors in interpretation, problems by having the original data set to refer back to.
- Avoiding potential site revisits for missed data (office base field checking)
- Fast turnaround where access time is restricted (e.g. railway possessions, contaminated areas, live motorways, etc)
- High accuracy plans for retro fitting design work, avoiding on-site alterations and clashes
- A reduction in re-work and ‘fit-up’ problems
- The ability to amend the scope of projects without requiring a return to site
- Avoiding the need for access platforms as the survey is entirely reflectorless
- An archive record of the site at a snapshot in time which can always be accessed even though it may no longer exist in reality !
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 can be 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 only limited by the imagination of the user. This may be a bold statement, but having successfully used this technique over the last four years, we continue to find new applications including:
- 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 can 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)
The benefits of working with laser scanning data are numerous and provide the advantage to multi-disciplinary teams; Architects, Civil Engineers, CAD Designers, Planners, Universities, Insurance Companies, Utility Sectors, Mechanical & Communicational Engineers the list goes on and is continually being added to.
What do I get as deliverables?
Laser scanning deliverables can be as simple or complicated as you require for any given project.
Some clients wish us to deliver the basic raw scan cloud data only. They can then archive the data for later use, use it for insurance purposes or use their in house CAD skills to extract line and point data from the cloud.
- Line work extracted as to a standard CAD DXF or DWG file is a common request. This may take the form
- Topographical plans
- Roof plans
- Building and structure elevations
- Cross and long sections
- Clearoute sections
- 3D wire frame line models (DXF / DWG)
- Rendered 3D models (AutoCAD, 3DStudio or Sketchup models)
- Animated visualisations (AVI or MP4)
- IMP, PTX, PTS, POD files (Pointools)
- BIM in Revit or IFC for import into other BIM systems (see scan to BIM page)