3D laser scanning is the geodetic technique by which the geometry of a structure can be measured fully automatically without the aid of a reflective medium. With 3D laser scanning, a three-dimensional image of a surface can be obtained. It is called a “point cloud” because of its high density (millions of points).
Laser scanning systems operate according to one of three measurement principles: time of flight (TOF), triangulation and phase difference measurement. In the case of TOF scanners, the distance is calculated by measuring the return time of a sent laser pulse. When it comes to triangulation, the 3D coordinates of the measured point are determined by the forward insection method. Phase measurement is the emission of a modulated signal and the determination of the phase difference of the returned signal from the time of emission.
Is 3D scanning fast?
The scanning speed depends very much on the scanner and its field of view. With laser scanners, you will usually be able to see the acquired points “on screen” in real time. By performing scans at different angles to ensure that all geometry is covered, a point cloud is obtained.
Also, when it comes to
3D laser scanning
scanning, the number of dots per second scanned, the width or scanning band and the density of dots per line are important.
When is 3D laser scanning used?
The steps to set up the 3D scanner are easy, as the device is used in:
- Indoor or outdoor topographic measurements with very high accuracy;
- Digital archiving of any lens;
- Archaeology – thanks to the invasive method the archaeological site is accurately inventoried without physical damage;
- Architecture and Restoration – site plans or measurements of building facades are carried out for rehabilitation purposes;
- Measurements for the positioning of pipelines, networks, cables or other technical equipment in industrial sites during or after completion of construction;
- Create animations or movies that give a virtual 3D perspective of the lens;
- Industrial measurements during construction to determine areas, distances or volumes, so that project information is better managed;
- Identifying errors in 2D documentation;
- High precision measurements in the field of construction or rehabilitation of access roads;
- Measurements of buildings, bridges, dams, etc. useful for 3D monitoring works;
- Measurements of pipes, horizontal or vertical tanks to determine their position, volume or deformations.
3D scanners can statically scan the surfaces targeted by the spectroscopists in the field, with the machine remaining in a fixed position in this case, delivering very high accuracy results. There is also the possibility to install a 3D laser scanner on a moving platform and even on a flying machine.
Also, if you want to effectively scan the environment or a specific structure, the scanner can be placed on a moving vehicle. However, it should be noted that in these situations the costs will be much higher as the operations performed are more complex and additional equipment is needed.