LiDAR, which stands for Light Detection and Ranging, is a sophisticated remote sensing technology that utilizes laser light to measure distances and create detailed three-dimensional representations of the Earth’s surface.
What are the components of Lidar?
A LiDAR sensor comprises four main parts: the laser, the scanner, the detector, and the processing unit.
- Laser: The laser is the source of the light that is used to measure the distance between the sensor and an object. It is responsible for emitting pulses of light at a very high frequency. The laser used in LiDAR sensors can be either a solid-state or a gas laser.
- Scanner:The scanner is responsible for directing the laser beam in different directions. It rotates or oscillates to scan the environment and collect data. This allows the sensor to create a 3D point cloud of the environment by measuring the distance to different objects in the scene.
- Detector:The detector is responsible for receiving the light that is reflected back from the objects in the scene. It converts the light into electrical signals that can be processed and analyzed. The detector can be either a photodiode or a photomultiplier tube.
- Processing Unit:The processing unit is responsible for analyzing the data collected by the sensor. It processes the electrical signals from the detector, and converts them into usable information. The processing unit can include a microcontroller, a computer, or a specialized ASIC (Application-Specific Integrated Circuit).
The sensor’s capacity to precisely estimate item distances and produce intricate 3D models of the surroundings depends on each of these components.
How does Lidar work?
The basic operational principle of LiDAR involves emitting laser pulses towards a surface and measuring the time it takes for the reflected light to return. The distance is calculated using the formula:
Distance = (Speed of Light × Distance) / 2
This process generates a dense collection of points known as a point cloud, which represents the three-dimensional shape of the scanned environment. Each point in this cloud has specific coordinates (latitude, longitude, height) that correspond to a location on the Earth’s surface.
What are the benefits of using Lidar technology?
There are a number of benefits to LiDAR, and in almost every instance LiDAR is a better alternative to other 3D modeling systems, like photogrammetry.
First, LiDAR is incredibly accurate, with some systems able to target objects as nebulous as a cloud or as small as individual molecules. Photogrammetry, which takes hundreds of thousands of photographs and synthesizes them into one model, is much more data intensive than LiDAR and rarely as accurate.
Another benefit of LiDAR is its ability to work in low light or areas of little visibility.
Photogrammetry systems are rendered inoperable by dark spaces like mines or dark skies, but LiDAR technology has no problem working in such environments since it operates with infrared lasers.
This is a major benefit of using LiDAR over other remote sensing technologies because, as we will see below, many of the industries using LiDAR today are involved in safety or emergency services. In these instances, the ability to capture accurate measurements regardless of environmental circumstances can be vital to saving lives and keeping civilians safe.
Reference for further reading
Understanding LiDAR: Technology and Applications. (n.d.). Retrieved November 4, 2024, from https://www.flyability.com/blog/lidar
What are the components of a LiDAR sensor? (n.d.). Retrieved November 4, 2024, from https://learn.rockrobotic.com/what-are-the-components-of-a-lidar-sensor
