What is LiDAR?

LiDAR (short for “light detection and ranging”) is a measurement technology that uses laser light to determine the presence (“detection”) and distance (“ranging”) of physical objects. A LiDAR sensor sends out laser light pulses and then measures the time it takes for the reflected light to return to the sensor. The shorter the time it takes for the light to reflect back to the sensor, the closer the object is to the sensor.

In some ways, LiDAR is similar to RADAR (“Radio Detection and Ranging”), which uses radio waves instead of light to make measurements. However, while RADAR technology can measure and detect far-away objects, LiDAR systems can provide detailed, high-resolution images of objects and surroundings. This is why LiDAR technology is often used in mapping, navigation, meteorology, facial recognition, and even household appliances.

Brief History of LiDAR

The first LiDAR systems were developed in the 1960s. They were one of the first technologies to use the laser, which was invented in the late 1950s. Meteorologists were among the earliest LiDAR adopters, using the technology to measure clouds and air quality. In the 1970s, astronauts used LiDAR to map the moon’s surface. Since then, LiDAR has gained popularity as it has made its way from highly specialized and scientific fields to everyday life.

The advantages of LiDAR

  • Extremely precise distance measurement: Scientists use LiDAR to measure the distance from the Earth to the moon within a few millimeters.
  • High-resolution imagery: LiDAR images are detailed enough to show not just the presence of objects, but their shape, texture, and orientation as well. Surveying aircraft can even use LiDAR to map surfaces and features underneath trees and vegetation.
  • Dynamic 3D imagery: LiDAR scanners can generate timescale 3D images. Scientists can, for instance, use LiDAR images to identify flying insect swarms — down to species — and minimize their impact on agriculture

Lidar description and benefits in a text box

Where is LiDAR used?

LiDAR devices and systems are used in dozens of industries. Two well-known applications include:

1. Autonomous vehicles and assisted navigation

Today, LiDAR systems are perhaps most famously used in autonomous vehicles, which use LiDAR arrays to constantly scan surroundings and detect other vehicles, traffic signs and signals, pedestrians, cyclists, and road debris.

However, even a “traditional” vehicle driver might already benefit from LiDAR technology. Some Advanced Driver-Assistance Systems (ADAS) use LiDAR in combination with other technologies to alert drivers of obstacles when parking. Other ADAS’s use LiDAR to brake and maintain safe vehicle distance while on cruise control. The most advanced vehicles can use all of these functions to park themselves!

2. Meteorology and astronomy

Meteorologists and astronomers use LiDAR technology to measure conditions on earth, the moon, and even on Mars. LiDAR images provide detailed information about cloud size and density as well as altitude and movement. Because different molecules and atoms reflect and scatter light in predictable ways, LiDAR systems can also measure atmospheric composition, as well as water vapor and dust particles.

The weaknesses of LiDAR

With all of the advantages of LiDAR technology, there are a few weaknesses. Compared to radio waves used in RADAR systems, LiDAR’s light waves don’t work as effectively over long distances or in poor weather conditions such as heavy rain.

In addition, LiDAR systems are relatively expensive. While many car manufacturers are embracing LiDAR, the electric carmaker Tesla is a notable exception. Instead, Tesla cars incorporate less expensive RADAR and camera technology to provide the same combined capabilities as a LiDAR system.