There are many kinds of 3D laser scanning systems currently applied, with different types and working fields. According to different research perspectives and working principles can be categorized in many ways.
Three-dimensional laser scanning system from the operation of the spatial location can be divided into the following four categories:
Airborne laser scanning systems
This kind of system is carried on the unmanned aircraft or manned helicopter, which is composed of laser scanner, imaging device, positioning system, flight inertial guidance system, computer and data collector, recorder, processing software and power supply, and it can obtain a wide range of three-dimensional feature data in a very short time.
Ground-based laser scanning system
This kind of system is a kind of measurement equipment that utilizes laser pulse to scan the measured object, and can obtain the three-dimensional shape and coordinates of the ground object in large area, fast speed, high precision and high density. According to the measurement mode can also be divided into two categories: a mobile laser scanning system; a fixed laser scanning system. The so-called mobile laser scanning system, is based on vehicle platform, by the global positioning system, inertial navigation system combined with the ground three-dimensional laser scanning system. The fixed laser scanning system is similar to the total station in traditional surveying. The system consists of laser scanner and control system, built-in digital camera, post-processing software and so on. The difference with the total station is that the fixed laser scanner collects not discrete single-point three-dimensional coordinates, but a series of "point cloud" data. It is characterized by large scanning range, fast speed, high accuracy and good field operation performance.
Handheld Laser Scanners
This type of equipment is used to collect 3D data from small objects, and is generally used with a flexible robot arm. The advantages are speed, simplicity and accuracy. It is suitable for many fields such as mechanical manufacturing and development, product error detection, video animation and medicine.
Laser scanners for special applications
Such as caves in the application of the laser scanner in a particular very dangerous or difficult to reach the environment, such as underground mine tunnels, caverns, tunnels and other small, elongated space such as artificially excavated tunnels, 3D laser scanning technology can also be carried out three-dimensional scanning.
Three-dimensional laser scanning system in accordance with the scanner's ranging principle, but also divided into the following three categories:
- The use of pulse ranging technology. Its range can reach hundreds of meters, or even thousands of meters.
- Based on the phase measurement principle. Mainly used for medium-distance scanning measurements, the scanning range is generally within 100 meters, compared with the use of pulse ranging principle of scanning equipment, its accuracy is relatively high.
- Optical triangulation principle. Using optical triangulation principle of scanning equipment, generally working distance is relatively close, within a few meters or tens of meters, mainly used in engineering measurement and reverse modeling and other projects, can achieve high measurement accuracy.
