All about Terrestrial Laser Scanners

Terrestrial Laser Scanners are used to collect comprehensive 3D data on items on the ground. The models may be created quickly and inexpensively using laser scanning. Deformation measures, quality control, topographical surveying, and cultural heritage monitoring are areas where Terrestrial Laser Scanners (TLS) can be used.

Also known as long-range laser scanners they help create point clouds of enormous outside environments or interiors of massive buildings. They are used in point cloud modeling services and various industries for surveying, site inspection, and much more. They measure points from a considerable distance, usually tens or hundreds of meters.

With the widespread use of 3D applications, the market for terrestrial laser scanning has grown at an exponential rate. The 3D terrestrial laser scanner is in high demand due to its constant technological advancements and lowering training costs. Furthermore, the 3D terrestrial laser scanner's all-in-one design includes a built-in scanner, display and control buttons, a powerful camera, and ample data storage capacity. Because of their lower power consumption, size, weight, and price, 3D terrestrial scanners have become popular on the market. They've also been given a higher-quality camera to catch dark and oblique surfaces with more precision.

How do Terrestrial Laser Scanners Work?

Contactless measuring technologies, such as terrestrial laser scanners, may capture dense point clouds of things. Each point is given an X, Y, Z coordinate and a color and reflectance value following processing. The relative precision is better than 10-4, which is the ratio of absolute precision to the measurement range. For surveying applications, this technology is becoming increasingly significant.

The practice of terrestrial laser scanning is placing one of these LiDAR-based scanners in or near the scanned object or environment, usually on a tripod. The data is then captured as a point cloud, a spatial, 3D data points collection.

For acquiring the data from several angles, the scanner must be moved and set up at various static places. For example, to get an accurate 3D scan of a structure, you'll need to scan it from multiple angles.

When scanning numerous big areas, the software performs point cloud registration, integrating the individual data sets into one complete set.

Lasers produce coherent and monochromatic electromagnetic energy. The emitted beams are very directed, have a lot of energy, can travel hundreds of meters, and are reflected off of things' surfaces. These are extremely advantageous qualities, and lasers are increasingly being employed as the primary component of distance measurement devices capable of creating 3D models of objects of various sizes and shapes.

What is the Software used in Terrestrial Laser Scanners?

Controlling the scanner during surveying and processing the raw data into measurable point clouds and 3D models. The control software that controls the scanner's movement visualizes object points during scanning in 2D or 3D, and the laser scanner’s manufacturer normally provides onsite data cleaning. The most difficult and important operation, which is converting raw data into measurable 3D models, is completed in the office using pricey application software.

TLS software may have the following features:

Data from point clouds is registered (automatic or manual)

Filtration of noise

Tagging for target identification

Geo-referencing

Creating a report

3D modeling error reporting

Texturing

Cloud-based file sharing

Some mobile field software solutions can provide real-time scan data feedback, which is important for on-site inspection and quality control jobs that must be done within a certain amount of time.

Types of Terrestrial Laser Scanners

Some of the types of Terrestrial Laser Scanners are-

Fixed laser scanners: This classic terrestrial laser scanner is the latest technology in point cloud modeling services. It produces high-quality output by using precise measurement data. Workhorse scanners such as the Faro Focus, Z+F Imager 5016, and Leica RTC360 fall under this category.

Traditionally, these sensors have been set up in various settings, with fake targets placed correctly to detect the relative position of scans. A fixed laser scan survey captures the spatial detail of an existing building in 3D quickly and accurately. To get this data, surveyors employ high-tech HD laser scanners. Land surveying, mining, as-built surveying, architecture, archaeology, monitoring, civil engineering, and city modeling are just a few of the applications. Construction design teams can use laser scanning surveys to acquire exact geometric data for their project models, which can then help with the BIM process.

GNSS-guided mobile scanning: Mobile laser scanning (MLS) is now widely used for large-scale point cloud acquisition. One or more laser scanners installed on a vehicle make up a typical mobile LiDAR system. Global Navigation Satellite Systems (GNSS) and a high-grade Inertial Measurement Unit are used to establish the vehicle's trajectory (IMU).

For gathering odometry data, a wheel rotation sensor is frequently incorporated. For several years, such systems have been commercially available and can attain an accuracy of a few tens of millimeters. Their advantage is the ability to rapidly acquire larger amounts of data and cover big areas in a short length of time.

These scanners are perfect for scanning data from boats, trains, and vehicles used outdoors. Indoor applications are not possible with this type of technology. This largely depends on their dependency on GNSS, which is impossible to use inside a structure.

SLAM and IMMS: Indoor Mobile Mapping Systems (IMMS) aims to take GNSS systems' mobile flexibility and apply it to situations where GNSS signal strength is too weak to operate. Scanning should be significantly faster as a result of this. However, it's also the scanning category with the least advanced technology - and the least precise results.

SLAM is an algorithm that attempts to create a map of an unknown area while also navigating it using the map. It's extensively employed in autonomous robotics, and wearable, mobile scanning technology is increasingly being used in surveys.

Applications of Terrestrial Laser Scanners

The terrestrial laser scanner is a new type of survey and mapping measurement equipment that can quickly and efficiently obtain three-dimensional point cloud data of an object, breaking through the traditional data collection method of point cloud to 3d modeling services.

Many businesses require sub-centimeter accuracy; hence terrestrial laser scanners are utilized to acquire visual data. The following are examples of applications and industries:

Land surveying, mining, and architecture, engineering, and construction (AEC)

Topography, Geomorphology, and Forestry

Deformation measurement, quality control, metrology

Reverse engineering, industrial design, and customization

Fashion, CGI, and Video Games

Accidents, Crime Scenes

Digital city, Deformation Monitoring, Digital, Cultural Heritage Protection

Conclusion

New hardware scanning technologies will need to integrate with the digital world of BIM and cloud-based processing in the future. Scanners must be integrated with other reality capture tools into a wider range of workflows to improve the value of scan data to all stakeholders. Surveyors must understand these new technologies and cloud-based advancements since they will result in significant cultural and procedural changes. The skill to manage this technological revolution is crucial.

Judith Morrison is an expert in the field of industrial engineering and writes articles related to piping, civil, equipment engineering related articles.