LIDAR

LIDAR, which stands for Light Detection and Ranging, is a remote sensing technology that measures distances by illuminating targets with laser light and analyzing the reflected pulses.

- Words By: Shintu Dhang

Often described as "radar using light," LIDAR creates high-resolution 3D maps of environments in real-time. The concept was first introduced in the 1960s, following the invention of the laser, and it gained significant attention in the 1970s during NASA's Apollo 15 mission, which utilized LIDAR to map the Moon's surface. Today, miniaturized and affordable LIDAR sensors are used in a variety of applications, ranging from autonomous vehicles to consumer smartphones.

HOW LIDAR WORKS

A LIDAR system consists of three main components: a laser emitter, a scanner, and a detector. The emitter sends out rapid pulses of near-infrared laser light, typically at wavelengths of 905 nm or 1550 nm, which are invisible to the human eye. These pulses travel at the speed of light, approximately 300,000 km/s, until they hit an object and bounce back.

Scanners direct the laser beam using rotating mirrors, micro-electromechanical systems (MEMS), or solid-state phased arrays. Flash LIDAR, on the other hand, skips the scanning process entirely by illuminating entire scenes at once with a diffused laser pulse, similar to a camera flash. The resolution of a LIDAR system depends on the pulse frequency, scanner precision, and detector sensitivity, with top systems achieving millimetre accuracy at distances of up to 200 meters.