US What LiDAR means
LiDAR stands for light detection and ranging. It is a sensor that measures distance by firing pulses of laser light and timing how long each one takes to bounce back from a surface. Repeating this many thousands, or millions, of times a second in different directions builds a 3D point cloud of the surroundings.
The technique followed soon after the invention of the laser in 1960 and was first used for weather and atmospheric research and for measuring the distance to the Moon. Today it guides autonomous vehicles and robots, maps terrain from aircraft and is even built into some smartphones for depth sensing.
How LiDAR works
A LiDAR has three parts: a laser that emits short pulses, a scanner that points them in different directions, and a detector that catches the reflections. For each pulse, the sensor measures the time of flight, the time between sending the pulse and receiving its echo. Because light travels at a known speed, distance is half the round-trip time multiplied by the speed of light. A round trip of about 6.7 nanoseconds means a surface 1 m away.
Each measurement becomes one point with a direction and a distance, often with an intensity value showing how reflective the surface was. Thousands of points together form the point cloud, which software then filters, clusters and classifies to find the ground, walls, vehicles and people.
Most industrial and automotive LiDARs use near-infrared light at 905 nm or 1550 nm and are rated Class 1 eye-safe under IEC 60825-1, so they can be used around people.
Types of LiDAR
Mechanical LiDARs spin to scan all the way round; solid-state designs steer the beam electronically or flash a whole scene at once. The table summarizes the main types.
| LiDAR type | How it scans | Field of view | Typical use |
|---|---|---|---|
| Mechanical spinning | A rotating head sweeps several laser channels around | Full 360° horizontally | Robotaxis, mapping, research vehicles |
| MEMS | A tiny moving mirror steers the beam | Forward-facing, often around 120° | Automotive and industrial vehicles |
| Flash | Lights the whole scene at once, like a camera flash | Wide, short range | Robots, docking, short-range detection |
| Optical phased array | Steers the beam electronically with no moving parts | Forward-facing | Emerging solid-state designs |
| FMCW | Measures distance and speed from a frequency-swept beam | Varies by design | Long-range automotive, velocity sensing |
LiDAR is also grouped by platform: airborne LiDAR maps terrain from aircraft and drones, terrestrial LiDAR scanners sit on tripods for surveying buildings, and mobile LiDAR rides on vehicles and robots.
Key LiDAR specifications
When comparing LiDARs for a machine, these figures on the datasheet matter most:
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Range. Usually quoted at a stated reflectivity, such as 10%, because dark targets return less light.
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Channels or resolution. The number of laser lines, or the angular resolution, sets how finely the sensor sees small or distant objects.
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Points per second. From hundreds of thousands to several million, which sets the data load on the computer.
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Field of view. Horizontal and vertical coverage, and whether one sensor or several are needed around the machine.
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Ingress and temperature ratings. For outdoor machines, check the IP rating, operating range and window heating.
What LiDAR is used for
Anything that needs accurate 3D shape or distance can use LiDAR. The main applications are:
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Autonomous vehicles. Detects obstacles, people and other vehicles around the machine.
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Robots and AMRs. Maps buildings and plans routes around obstacles.
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Construction and mining. Tracks stockpile volumes, movement and changes on site, and guides autonomous mining machines.
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Surveying and mapping. Captures terrain and structures in detailed 3D.
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Traffic and security. Counts and tracks vehicles and people while recording no faces or number plates.
Strengths and limits
Because each point is a direct distance measurement, LiDAR gives accurate depth without relying on daylight, though heavy rain, fog and thick dust can scatter the beam. Very dark or shiny surfaces, such as black cars or wet roads, can return weak or misleading echoes. LiDAR also gives no color, so it cannot read signs or tell a red light from a green one on its own.
That is why LiDAR is usually combined with cameras and radar through sensor fusion, each covering the gaps of the others.
Processing LiDAR data
A LiDAR produces a lot of data, so the computer that processes it matters as much as the sensor. A typical 3D LiDAR outputs hundreds of thousands of points a second, often several million, over Gigabit Ethernet, and many are powered over the same cable with PoE. NVIDIA Jetson PoE systems can power and connect LiDARs and cameras directly.
Our construction case study runs LiDAR on rugged Jetson computers with PoE. See our rugged Jetson computers for sealed systems that run point cloud processing and AI side by side.
Quick answers on LiDAR
LiDAR: common questions
What does LiDAR stand for?
Light detection and ranging. It is often written LiDAR, LIDAR or lidar. All three mean the same thing.
What is a LiDAR scanner?
A LiDAR that sweeps its beam to capture a scene. Surveyors use tripod scanners for buildings and sites; vehicles and drones carry mobile scanners for mapping.
Can LiDAR see through walls?
No. Laser light is reflected or absorbed by solid surfaces. LiDAR can see through gaps in foliage, which is why airborne LiDAR maps the ground under forests.
Does LiDAR work underwater?
Only in a specialized form. Bathymetric LiDAR uses green light that penetrates clear, shallow water to map the seabed. Standard near-infrared LiDAR is absorbed by water.
Is LiDAR safe for the eyes?
Yes, for Class 1 devices. Most automotive and industrial LiDARs are rated Class 1 under IEC 60825-1, which is eye-safe in normal use.
We supply rugged edge AI computers with the Ethernet, PoE and processing that LiDAR systems need, integrated with your sensors and software as standard. Tell us the LiDARs, cameras and machine, and we will specify the system to run them.