What is 3D Laser Scanning?
3D Laser Scans or High Definition Surveys (HDS) has become the most efficient way of creating or verifying 3D As-Built models. A laser scanner recreates its surrounding environment by measuring a high density array of point positions to form a "point cloud". This point cloud can be digitally viewed, sliced, used for distance measurement, volume calculations and solid modeling.
Scanning Equipment used by Lloyd & Hill Inc
 Leica HDS6100
The Leica HDS6100 is an ultra-high speed, phase-based, medium range scanner |
In March 2006, Lloyd & Hill Inc. became the first company in South Africa to own a high speed, phase-based HDS4500 scanner from Leica. In October 2007, LHI took delivery of its latest phase scanner, the HDS6000 with its extended range and higher resolution. Then in April 2009 this was upgraded to an HDS6100, improving on range noise, performance in high-reflectivity environments, and operating temperature range.
Both these scanners are capable of capturing up to 500 000 points per second. The HDS4500, currently available for hire from LHI (contact us) has a range of 53m. This is well suited to mobile scanning or corridor mapping applications such as tunneling and breakwaters.
These scanners are ideal for dense, short-range scans typically required in the industrial environment. To learn more about these scanners, view the specifications at HDS6100 Info and HDS4500 Info.
For longer range work a pulse-based HDS3000 or ScanStation scanner is more appropriate. Lloyd & Hill have used these instruments to good effect in the marine and petrochemical environments, where high accuracy is required over longer ranges. For more about these scanners view the specs at ScanStation Info.
Our Scanning Philosophy
LHI believe that scanning must be grounded on an accurate survey that firmly relates the point cloud to the site coordinate system. Therefore our scanning team comprises well trained survey technicians managed by a professional surveyor who ensures that the overall registration and work flow will meet project specifications.
Ideally a point cloud should generate very high relative accuracy within a given cube but maintain good absolute accuracy across the whole site. This is achieved with well controlled and high precision survey performed simultaneously with the scans.
We aim to scan as much as possible in a day on site with the security of checked survey measurements within the accuracy specs and with the due safety precautions that are prescribed for work in that area.
Products and Applications
Just about any environment, natural or man-made can be modeled by a point cloud acquired with a 3D scanner, such as:
Industrial Design & Fabrication:
A 3D point cloud that accurately represents reality is used by engineers in the design of modifications and new plant that must be integrated with existing components. The advantage of knowing in detail what exists in the as-built environment results in substantial savings by ensuring that pre-fabricated equipment fits first time. Furthermore, all detail in view of the scanner is captured in the field and can therefore be identified and measured at any stage using the scan model, without the need to revisit a site.
Point clouds are fast becoming a standard requirement in reverse engineering projects.
Historical Records:
Architectural and archaeological records can be stored in digital form by scanning buildings or artifacts, and colouring them according to the images. Any measurements can be made, or 2D plans generated subsequently using the digital 3D model.
Products
The basic product in a project is a 3D point cloud. A wide variety of products can be generated from a point cloud, including 2D plans and sections that can be created by "slicing" the model at any position.
| Products |
Applications |
| 3D Point Cloud |
Architecture: as-builts |
| Modeled Solids and Surfaces |
CBD streetscapes |
| Fly-through visualizations |
Civil, structural and pipe engineering |
| TIN/DEM/MESH Surfaces |
Archaeology & Heritage documentation |
| 3D Line drawings |
Petrochemical – Reverse Engineering |
| Volume calculations |
Shipping: modification/body&lines |
| Sections/2D line drawings |
Geo-technical slope monitoring |
| Time based progress records |
Construction QC
Tank calibration
Film Industry – sets/scene/model |
Spherical Imagery
One of the products offered by Lloyd & Hill is a spherical image, typically captured from the same position as a scan. This allows the user to scroll around a scene and view it from any angle from the point of photography.
The spherical image can be a stand-alone product, but is often used in conjunction with a point cloud to assist the scan user with a photographic replica of the scene.
3D Desktop Measurement
Using a free viewer, measurements can be taken from laser scan data using the spherical image format described above.
The effect is similar to bringing a site to your desktop where queries can be resolved without leaving the office.
The data can be displayed in a false shade using the various levels of return intensity from the laser, or in true colour based on the photography.
Snapshots showing greyscale intensity-based
spherical image with measurements (left) and true colour (right)
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