LiDAR stands for ‘light detection and ranging’ and is a technique for measuring the distance of objects from a sensing device. The principles used are very similar to RADAR but, with LiDAR, the radio waves are replaced by light – usually laser light. The LiDAR system emits a beam of light that hits a target before being reflected back to a sensor that is located close to the light source. By measuring the time taken for the light to travel, and knowing the constant speed of light, the distance of the target can be calculated with a high degree of accuracy. By repeating this measurement at regular intervals across a scene or target area, a 3D map of the environment can be built up.
LiDAR has applications in the automotive world, particularly in the advanced driver assistance system (ADAS) where it can be used for obstacle detection and collision avoidance as well as adaptive cruise control (ACC) and navigation. However, while the automotive uses are frequently talked about, they represent a very small proportion of the total applications for LiDAR.
In space exploration, LiDAR can be used to create 3D topographical maps of the surface of planets, or to calculate the distance between a celestial body and Earth. Agriculture uses LiDAR to survey fields and crop conditions, allowing farmers to model and predict crop yields as well as monitoring crop growth.