Laser radar (LIDAR) is a sensor that is currently changing the world. It is widely used in autonomous vehicle, unmanned aerial vehicles, autonomous robots, satellites, rockets, etc.
What is laser?
Regarding the invention of lasers, we can trace it back to Einstein's basic theory of stimulated radiation established in 1917. When a particle at the high energy level is excited by a certain photon, it will transition from the high energy level to the low energy level. At the same time, it will release a photon with the same frequency, phase, propagation direction and polarization state. The light emitted by the excitation is called LASER, which was first translated as laser, and now we translate it as laser.
What is LiDAR technology?
According to the American Institute of Earth Sciences, LiDAR uses pulsed laser to calculate the variable distance between an object and the Earth's surface. These light pulses, combined with information collected by airborne systems, can generate three-dimensional information about the Earth's surface and target objects.
LiDAR follows a simple principle - to emit laser light towards objects on the Earth's surface and calculate the time it takes to return to the light source. Considering the propagation speed of light (approximately 300000 kilometers per second), the process of measuring distance using LiDAR is very rapid. However, this is very professional. The formula used by analysts to calculate the distance between objects is as follows: the distance between objects=(speed of light x flight time)/2.
How does LiDAR work?
Firstly, LiDAR does not operate independently, but consists of three main modules: laser transmitter, receiver, and signal processing.
Its basic working principle is to emit a type of laser, which is refracted back upon encountering an object and received by a CMOS sensor to measure the distance from the body to the obstacle.