What is LiDAR? How everyday devices use lasers to scan your environment

• LiDAR, also known as Light Detection and Ranging, uses lasers to measure the distance, shape, and orientation of 3D objects.
• LiDAR is becoming increasingly common, appearing in devices like the iPhone 12 Pro, robot vacuums, and self-driving car prototypes.
• These devices use LiDAR lasers to scan the environment around them, getting a more accurate picture of how the area is shaped and what objects they're near.

Modern electronics are bristling with cameras, Bluetooth, and other less common sensors. LiDAR is one such sensor that's found its way into Apple's iPhone 12, as well as many robot vacuums and most self-driving cars.

LiDAR stands for Light Detection and Ranging and is like RADAR but substitutes laser light in place of radio waves. And it's an increasingly important sensor in consumer electronics.

What LiDAR is and how it works

You might be aware that RADAR (Radio Detection and Ranging) transmits radio waves and measures the time it takes to get a return signal, which provides information about how far away objects are.

LiDAR works much the same way, measuring the "Time of Flight" (ToF) of a laser beam to get information about objects the laser bounces off of.

LiDAR has a big advantage over RADAR, though. Because light has a much shorter wavelength than radio waves, it's more accurate and can paint a more detailed picture of the target. That means LiDAR doesn't just measure the distance to something; it can infer a lot of information about the object's shape, too.

That's not all; with repeated pings, it's possible to determine not just its direction of motion and speed, but its orientation as well. For example, a device with LiDAR can learn details about how nearby objects are turning and whether they're facing towards or away from the LiDAR device.

LiDAR isn't the first Time of Flight sensor to find its way into consumer electronics. Samsung has infrared ToF sensors in smartphones like the Galaxy S20+ and Galaxy S20 Ultra, for example, but they're not lasers, just infrared beams. The Galaxy phones also include an app called Quick Measure which uses ToF to estimate the size and volume of an object in front of the phone.

But true LiDAR sensors like the one in the iPhone 12 Pro send out a grid-like pattern of lasers as opposed to a single beam, which makes LiDAR more accurate and faster at developing a picture of the environment.

How LiDAR is used in consumer electronics

Historically, LiDAR is a scientific instrument that's been used in applications like aircraft and drones to map the surface of the earth. In recent times, the cost of LiDAR sensors has dropped and LiDAR is finding its way into more and more consumer-focused devices.

While the general application - developing a detailed picture of the local environment - is roughly the same, various devices use LiDAR differently. Here are the main applications in use today:

• Smartphones. The main use for LiDAR in smartphones like the iPhone 12 Pro is computational photography - specifically, using the depth-sensing capabilities of LiDAR to improve photo modes like night portraits. But LiDAR has a lot of potential for augmented reality (AR), in which computer-generated visuals are embedded in the real-world environment (as seen through the phone's camera) on the phone screen.
• Robots. Robot vacuums are increasingly using LiDAR for navigation and obstacle avoidance. Vacuums from brands like Wyze and Roborock, for example, can actually identify the kinds of obstacles they encounter (like differentiating a shoe from a child's toy) and better navigate around them.
• Cars. While Tesla currently doesn't feature LiDAR sensors in any of its cars with self-driving modes, many other prototype self-driving cars are relying in part on LiDAR to map terrain, roadways, cars, and people around the vehicle.

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