3D scanning

When is 3D scanning performed?

Based on the tasks set, as well as the characteristics of the object and the required data accuracy, the required 3D scanning method is selected or a combination of them is used to achieve the most effective result.

• Terrestrial laser scanning (TLS) is used when exploring large areas.
• Aerial laser scanning (ALS) is used for 3D scanning of large areas.
• Mobile laser scanning (MLS) is used to scan highways, railways or other linear objects with a significant length.

Terrestrial laser scanning (TLS) is the most common type of 3D scanning. This method of scanning is carried out when accurate and detailed information is required about the object for the following purposes:

1. Restoration.
2. Reconstruction of a building or structure.
3. Re-equipment of the enterprise, modernization, relocation of structures or equipment.
4. Unfinished object. Resumption of the construction process.
5. Development of a three-dimensional BIM-model of a construction object.
6. Monitoring the technical condition of the building.
7. Executive survey and monitoring of the state of construction objects.
8. Making adjustments to the project during the construction process, etc.

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What can you tell from a point cloud?

A point cloud, as an array of data, allows you to collect the following information about an object:

• Geometry of the construction object. The digital image includes a detailed plan of the premises.
• Object deformation and its deviations from the design standards.
• Technical condition of the building: surface defects, chips, fractures as well as defining construction or building readiness.
• Deformations development. When conducting a series (monitoring) of surveys, it is possible to establish deformations behavior over time.

The results of processing a geometric data set can be presented in both 2D and 3D formats.

The order of work with building laser scanning

First of all, 3D scanning specialist is setting up the laser and setting the shooting parameters. At this stage, the required density of cloud points, the color of the 3D scan and its quality are established and all ready for scanning (with different duration of data collection, different accuracy of the coordinates of the points can be obtained).

• Method determination for combining scans obtained from different locations of the device into a single cloud of points. The two main methods are by stamps or scan-to-scan.
• Placement of marks, if needed. If necessary, anchor the object to a geodetic coordinate system.
• Drawing up a map of the 3D laser scanner station locations to cover all areas of the object.

Equipment for laser 3D scanning

A terrestrial laser scanner is survey equipment with a set step which allows measuring the distance to points, rotating along the vertical and horizontal axes. Up to ten thousand measurements can be made in one rotation, and it also let 3D laser specialist to calculate the angular distance through which the coordinates are taken.

To carry out 3D scan of building, a map of the scanner's station locations is drawn up. The result of building scanning from one scanner location is a complex of data for the particular part of the object or area, presented in the form of a cloud points using a certain density and other parameters.

After carrying out 3D laser scanning, the obtained data can be combined into a single point cloud and, thus, an integral digital 3D image of the object can be obtained.

ROSEСO uses equipment with the appropriate accuracy characteristics depending on the required tolerances and conditions of scanning:

TOPCON GLS2000

Heavy and long-range 3D laser scanner for buildings. Allows specialist to collect data from the distance of up to 300 meters. This type of equipment is used for filming the facades of buildings and the surrounding areas. TOPCON GLS2000 is capable of collecting large amounts of data - up to hundreds of millions of points from one scanner position.