■ What is 3D laser scanning?

3D laser scanning* techniques are an effective and extremely accurate method of creating complete, three-dimensional documentation of the spatial geometries of an object. The 3D data recorded during laser scanning can also be simultaneously converted into detailed, photo-realistic 3D illustrations. This is achieved by combining real colour information from images taken using a high-resolution digital camera with the data from the 3D laser scan.

■ Advantages

3D laser scanning is considerably cheaper than conventional techniques thanks to accelerated surveying procedures and the reduction in time spent on site. 3D laser scanning technology is particularly well suited for recording landscapes and planning projects.

The method is also used for documentation and surveillance in building projects. The registration and documentation of existing buildings by means of laser scanning also serves as a basis for real estate market.

■ Practical applications

In architecture, 3D laser scanning is mainly used for measurements of buildings providing an economical solution for making basic surveys and accurate plans of monuments and ancient buildings. Exterior walls and interior spaces can be completely documented in three dimensions with an accuracy of 0.5 to 2.5 cm. This is especially interesting for older buildings that often do not exhibit any regular geometric features such as façades and roof constructions.

3D laser scanning is being used more and more often in the field of cultural heritage conservation* . In civil engineering, the method is suitable for surveying a wide range of building types, especially difficult-to-access structures, such as bridges and railway.

10 Decide if the following sentences are true (T) or false (F). Then, correct the false ones.

  T F
1. 3D laser scanning techniques are used
to create two-dimensional spatial
geometries of an object.

2. Photo-realistic 3D illustrations can
be created during laser-scanning.

3. Real colour information is useless.
4. Recording landscapes and planning
projects can take advantage of 3D laser
scanning techniques.
☐  ☐ 
5. Conventional surveying techniques
are cheaper than 3D laser scanning.

6. Laser scanning is particularly suitable
for accurate plans of monuments
and ancient buildings.
7. 3D laser scanning technology does not
have any application in the heritage field.

8. 3D laser scanner surveying is also used
in the field of civil engineering.

11 Read the text again and find the English equivalents for these words.

1. accuratezza

2. adatto

3. alta-risoluzione

4. contemporaneamente

5. facciata

6. monitoraggio, controllo

12 Read the following text and complete the table with the information required.

Surveying, recording and monitoring historical buildings

The laser scanning technique needs a scanning head to be mounted on a tripod. The scanner spins at very high speed while a low-energy laser fires a reflecting beam with extraordinary precision, recording up to 1 million points a second. The use of laser scanning for recording and archiving is now well established and English Heritage (EH) has produced good guidelines for the professionals. Scanning provides a highly accurate contoured surface of buildings and structures. By repeating a scan a few months or perhaps a year later and overlaying one scan over the other, three-dimensional movement in the surfaces can be detected. This provides a powerful tool for monitoring structural behaviour.

The benefits are significant when considering large building volumes and spaces where detail at height is important, such as cathedrals, tall façades and historical civil engineering structures.

Information required
1. Equipment

2. Recording

3. Usage by English Heritage

4. Monitoring

5. Benefits

6. Buildings

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