Laser scanning is a land surveying technique used for information-gathering in the land surveying field. With this method, they can accurately measure and collect data from objects, surfaces, buildings, and landscapes. Laser scanners create point clouds of data from the surface of an object. The collected information in the form of point cloud data, which consists of millions of 3D coordinates (XYZ coordinates).
3D Laser Scanning Survey:
3D Laser Scanning or LIDAR (Light Detection and Ranging) is the process of shining a reflectorless laser line over a surface in order to collect 3-dimensional data. The surface data is captured by a camera sensor mounted in the laser scanner which records accurate dense 3D points in space. The 3D survey points collected combine together to form a point cloud that represents the surface surveyed.
Point clouds can be viewed in multi hue colors (based on signal intensity return) or true color from a digital camera. This technique provides a solution for the rapid surveying of inaccessible surfaces or complex geometrical details. The data can be linked in 3D to your site grid and matched seamlessly with topographical survey plans, elevations, and sections.
First, laser scanning systems throw out light waves that bounce off of surfaces and reflect back to the sensor. The sensor then calculates how far away the surface is by measuring the time taken for the light beam to complete its journey. This process is known as the “time of flight” measurement. The distance measured is then used to calculate a coordinate for the tiny section of the surface hit by the laser beam. All of this happens in just seconds, and during a single scan, a laser scanner will collect millions of 3D coordinates.
When the point clouds from laser scans are processed, they form a digital representation of the scanned surfaces, demonstrating the dimensions and spatial relationships of topographic features and structures.
The Advantages of 3D Laser Scanning
Laser scanning has a number of advantages over alternative land surveying methods. Here are some of the reasons why businesses use 3D scanning for surveys.
- Laser Scanners Can Instantly Collect Data
Laser scanning is the fastest land surveying technique available. Laser scanners can collect millions of data points in seconds, reducing the budget, time, and resources needed to finish surveys. This method of surveying is ideal for projects that require a quick turnaround.
- 3D Scanning Systems Can Survey Unreachable Areas
Before laser scanning systems were introduced, surveyors could not access certain areas. But with vehicle-mounted LiDAR systems, organizations can collect point cloud data from areas that are off-limits. For example, drone-mounted LiDAR can survey unsafe sites and structures. Because laser scanning is a non-contact surveying method, it can also survey sensitive objects or areas, such as vulnerable historic sites.
- Comprehensive 3D Models Can Be Created from Scan Data
Perhaps the biggest advantage of laser scanning is that scan data can be used to create 3D CAD models. These 3D digital models can be used to analyze and evaluate topographic features, structures, and transport corridors. They can also be used to simulate industrial sites or construction projects.