A laser scan survey is a fast and accurate way of capturing the spatial detail of an existing building in 3D. Surveyors use high tech HD laser scanners to capture this information.
This video details the process of a laser scan survey from scan to point cloud creation and subsequent 3D model.
Construction design teams use laser scanning surveys to capture the base data for their project models. It is particularly valuable for use as part of the BIM process.
Laser scanners use LIDAR technology
LIDAR technology captures large amounts of data in a fraction of the time taken by more traditional surveying methods. (LIDAR stands for Light, Imaging, Detection and Ranging)
The laser scanner emits a beam of energy and calculates the x, y and z coordinates for each point of physical contact.
There are two types of laser scanners:
Phase based laser scanners. By comparing the phase wavelength shift between the returning pulse and the stored pulse the scanner can calculate the distance the beam has travelled.
Pulse based (Time of Flight) scanners. These determine distances by calculating the time taken for the pulse to reach an object and return to the scanner.
The individual scans are registered to create a ‘Point Cloud’
We register the laser scans to form a Point Cloud data file. We can then quickly share these with the project design team directly to their desktops. The design team can then use the Point Cloud as a visual record of the building. They can also “walk through” the building taking accurate dimensional measurements as required.
Architects and the design team use the Point Cloud as a valuable reference tool throughout the duration of a project. Removing the need for costly return visits to site.
Laser scan data is used at various stages of the construction process
In addition to the pre-construction survey for confirming existing site conditions, architects use laser scan throughout a construction project.
During construction the Design Team can use scans to check the progress of the building on site against the proposed designs. By comparing site data with proposed footprints, elevations and sections. In this situation the scan data forms a valuable part of the quality control process.
Post construction the project manager can verify that the physical building matches the proposed designs. They can then handover the as-built model to the Facilities Management team for use throughout the lifeof the building.