Three-dimensional laser scanning technology, also known as real scene replication technology, uses the principle of laser ranging and high-speed laser scanning method to obtain high-precision three-dimensional coordinate data and a large number of spatial point information on the surface of the measured object in a large area and high efficiency. It can quickly establish real three-dimensional models of objects and digital terrain models with high accuracy (up to millimeter level). It is another revolution in the field of Surveying and mapping after GPS technology. Today, we break down the systems and applications of 3D laser scanning.
Compared with the abstract representation of traditional two-dimensional plane drawings, three-dimensional laser scanning technology can directly reflect the true face of the real world. It has a wide range of applications, mainly including cultural relics and historic sites protection, architecture, planning, civil engineering, factory transformation, interior design, building monitoring, traffic accident analysis, legal evidence collection, disaster assessment, ship design, digital city Military, etc.
The Systems Of 3D Laser Scanning
1. Fixed laser scanning system
Also known as a ground 3D laser scanner, it is used to set measuring stations in different directions on the ground for scanning.
2. Onboard laser scanning system
Take the car as the platform to scan continuously and quickly in the process of continuous movement.
3. Airborne laser scanning system
Take UAV or UAV as the platform to scan places continuously and quickly in the air.
4. Handheld laser scanning system
The utility model belongs to a portable laser scanner, which is simple, fast, and light to use.
5. Backpack laser scanning system
Manual backpack operation is adopted, which can adapt to complex routes and environments.
The Applications Of 3D Laser Scanning
1. Protection of ancient buildings and cultural relics
According to the point cloud data obtained by scanning, the ancient building orthophoto is produced. Then, according to the orthophoto, the plane, elevation, section and other traditional construction drawings of ancient buildings can be drawn. According to the three-dimensional point cloud, the details are rich, and the model is more realistic and accurate, which is convenient for the subsequent repair, maintenance, and display of ancient buildings.
2. Engineering Field
- Topographic survey
One of the most basic applications of 3D laser scanning technology in the field of Surveying and mapping is topographic map drawing. The scanned fine point cloud can directly produce 3D terrain model, automatically extract contour lines, and obtain 3D and 2D data at the same time. Compared with traditional surveying and mapping methods, three-dimensional laser scanning has the advantages of high efficiency, rich details, and various forms of achievements. One survey, features, and terrain are obtained at the same time.
- Planning and design
The primary task of project planning and design is to obtain the project and surrounding environmental information. The more sufficient the environmental information, the more convenient the planning and design work is. The three-dimensional laser scanning technology is used to scan the project target environment to obtain a high-precision three-dimensional model, which is not only intuitive and true but also contains all the information of the project target. It can get twice the result with half the effort.
- Maintenance, repair, and measurement of old buildings
For old buildings, 3D scanning technology can be used to reverse draw CAD drawings to assist in design, construction and measurement.
- Engineering survey
Due to the characteristics of high precision and comprehensive scanning data, three-dimensional laser scanning technology can replace the traditional engineering measurement, solve the problems that can not be solved by traditional means in some aspects, and play a unique role.
The three-dimensional laser scanning of supervision survey is the reproduction of the real scene, and the data has objective reliability, which provides an effective basis for quality check of concealed works and key parts.
The completion survey requires the measurement of the actually constructed buildings. Based on the characteristics of real scene scanning and high precision, the three-dimensional laser scanning technology can play a unique advantage in the measurement of special-shaped buildings.
During tunnel measurement, a large number of data points on the tunnel surface are obtained through a three-dimensional laser scanner, which can generate a real tunnel model. Whether it is over and under excavation analysis or convergence deformation analysis, the results are more accurate.
- Deformation monitoring
Because the three-dimensional laser scanning technology has the characteristics of high precision, under certain conditions, the accuracy can reach within 1mm. Three-dimensional laser scanning technology can be used to monitor deformation. It mainly includes building deformation monitoring, foundation pit deformation monitoring, bridge deformation monitoring, tunnel deformation monitoring and surface deformation monitoring.
- Earthwork and volume measurement
The three-dimensional laser scanner is used to scan the on-site topography to obtain the on-site high-precision three-dimensional terrain data. After processing the relevant data, the earthwork quantity or its related volume can be calculated.
3. Power Management Field
For the built power network, it is necessary to effectively manage its line patrol to ensure the safe transmission of power. Multi-platform lidar system has the advantages of a high-precision point cloud and high-resolution digital image. Relevant distance measurement data of transmission lines can be obtained, which is applicable to the route selection and design of new lines, line patrol inspection of dangerous points of existing lines, line asset management, and various professional analysis.
Based on high-precision and high-resolution orthophoto camera and laser point cloud data, combined with the business requirements of overhead transmission line route design, the integrated process application of line route optimization design and tower optimization design is realized. The tower location is optimized based on the section, and various indexes of the line are statistically analyzed according to the tower location coordinate data and tower foundation section data.
The high-precision point cloud obtained by the UAV lidar system can detect whether the distance of buildings, vegetation, crossing, etc. to the line is standardized and whether the line spacing meets the requirements of safe operation. At the same time, the high-definition image is obtained by the camera. The inspector can judge the abnormality of the line equipment and channel indoors. According to the classified point clouds of the power line, vegetation, and ground, the vegetation near the power line can be calculated and marked, which can play the effect of early warning.
Through the collected high-precision laser point cloud and high-resolution digital image data, processed into Dom and DEM, combined with the classified point cloud, it can realize the three-dimensional modeling of the power line, restore the topography of line corridor, surface attachments (trees, buildings, etc.), three-dimensional position and model of line tower, supplemented by the input of line facility parameters, and realize the management of road assets.
4.Film and television production field
In film and television shooting, some special scenes and props cannot be photographed, or in the production of some large-scale cartoons, 3D laser scanning technology is used to scan and model the scenes or props, and then the computer is used for post-production, which not only greatly reduces human investment, but also makes the effect more realistic.
The application of 3D laser scanning technology is far from limited to the above scenes. Due to its high fit with the real 3D world and in line with the technical development trend of the big data era, the application of 3D laser scanning technology must develop rapidly and show its skills in relevant fields. Let’s wait and see.