The first scanning equipment:
Early scanning technologies were based on photogrammetry, using photographs from different angles to create 3D models. As technology developed, LIDAR became the main tool for scanning buildings. The first LIDAR systems were bulky, required manual operation and were relatively slow to collect data.
What scanners exist today?
Today, there is a wide variety of scanners available, depending on specific goals and requirements. Some examples include:
Terrestrial laser scanners (TLS): These are used for scanning objects, buildings, and landscapes with high detail. Brands such as Leica, Faro, and Trimble are examples of this.
Handheld scanners: These are portable and are often used for smaller objects or tight spaces in buildings.
Mobile scanners: These are mounted on vehicles and used for scanning large areas, such as urban environments.
Aerial scanners: These are deployed on drones or airplanes and are used to capture large landscapes, building exteriors, and locations.
How does scanning work?
Here is a basic overview of the scanning process, with LiDAR used as an example, broken down into five basic steps:
- The scanner emits a pulsed laser. This is called emission.
- The laser beam reflects off objects, which is the reflection.
- Detection: The scanner measures the time it takes for the reflection to return.
- Using the speed of light, the scanner calculates the distance between itself and the object, which is the calculation.
- Each reflected laser pulse contributes to a data point in a 3D space, forming a so-called “point cloud.”
What to do after scanning?
After scanning a building or structure, a comprehensive process of data processing and analysis begins. Initially, the raw scan data is often presented as a point cloud and processed with specialized software.
This includes removing noise and aligning and registering different scan datasets to create an accurate image. Then, these data are converted into detailed 3D models using software like Autodesk Revit, Bentley Systems, or SketchUp, which allows the physical structure of the building to be recreated in a virtual environment.
These models are then used for various purposes. For example, during the analysis phase, where they are examined for structural aspects and potential improvements are identified. For architectural or heritage purposes, the model is used to create virtual tours, animations, or other visual presentations that showcase the building’s features and design. A crucial step is the integration of these scan data into Building Information Modeling (BIM), which provides a comprehensive digital representation of the building’s physical and functional aspects.
Finally, these detailed scans can serve as a historical archive, essential for future renovations, restorations, or research on the building. In all these cases, this process shows the transformation of raw scan data into valuable, ‘multidimensional’ data that can be used for a wide range of applications.