Surveying buildings? Use laser scanners!

Technology has made giant strides in architectural surveying.

Today it is truly possible to say that the use of cutting-edge tools such as the 3D laser scanner has completely revolutionized the field of architecture.

This is not only because of improvements in the quality of the work, but also because of the more precise data collection made possible during the planning and design on paper of a construction or renovation project.

Quantitatively too, the data obtained is far greater and better detailed in outlines and surfaces, as they are reflected.

How architectural surveying changes with the use of the laser scanner

The principle underlying 3D laser scanning is based on the use of electromagnetic pulses; the laser, in this case, makes possible the amplification of light through the stimulated emission of radiation.

This bounces off the surface of the object it is aimed at.

The sensors on the scanner's receiving surface record this data to create a three-dimensional image. The unified image created by combining the visual data from multiple scans is called a point cloud.

This point cloud provides a 360-degree image for processing that can be viewed from an infinite number of perspectives.

The 3D laser scanner is an extremely valuable tool for collecting all the essential data needed when starting a construction or restoration job, as it makes it possible to obtain information in digital format that can be preserved and stored better and for longer, as well as, of course, shortening work processes.

3D laser scanner: its main application in architectural surveying

When we talk about architectural surveying, we believe that the laser scan finds its main application in the construction and restoration of buildings.

However, this is not the only purpose, even if it is the main one.

There are many projects for which the use of this highly refined technology is an added value for many professionals. In order:

• In cultural heritage: it is a very useful, non-invasive tool that makes it possible to plan actions on buildings, including the recovery of archaeological heritage;
• In civil works: it supports engineering in the geometric survey of any structure and in the calculation of earth movements. Essential data in the construction of roads, railways, etc.;
• In the environmental sector: it makes it possible to obtain a series of essential data for the technical sheets of environmental impact studies, which necessarily accompany most architectural works.

The use of 3D laser scanner equipment in architectural surveying also makes it possible to obtain all the information needed to capture the morphology of the structure at its most significant points and to view them in 3D.

By querying the point clouds it is in fact possible to highlight any critical issues that are not always easy to detect with the naked eye. But there is more: direct reading of the building can support what has been assessed visually regarding the working techniques, the structural elements and the materials it is made of, as well as allowing any situations of deterioration to be recorded.

3D laser scanner equipment can also support traditional photogrammetry when the particular lighting conditions are not available.

For three-dimensional modelling, in all those situations where you want to model a large object such as the exterior of a building or a poorly lit area, it could be almost impossible to create an accurate, let alone complete, model of an object or structure without the use of a 3D laser scanner. The accuracy of the scans depends mainly on size, lighting and the ability to obtain the different shooting angles needed for the overlapping images that are essential in a complete 3D rendering.

The advantages of 3D laser scanning carried out with dedicated drones and related accessories are truly many; among the most evident we can find:

• Precision: a laser scan is certainly the most accurate form of measurement available;
• Speed: a laser scanner can capture up to one million 3D data points per second;
• Safety: 3D scanning makes it possible to obtain measurements in dangerous and often hard-to-reach places, thus keeping workers safe. In addition, the scan is completed safely from the ground without the need for cranes, lifts or cabling.