A Brief History of LIDAR

To understand why there’s so much support behind LIDAR today, it’s important to look at other similar technologies which have similar goals.

Sonar

The original depth-sensing robot was the humble Bat (50 million years old!). A bat (or dolphin, among others) is able to perform some of the same capabilities as LIDAR using echolocation, otherwise known as Sonar (sound navigation and ranging). Instead of measuring light beams like LIDAR, Sonar measures distance using sound waves.

After 50 million years of biological exclusivity, World War 1 advanced the timeline of the first major deployment of man-made Sonar sensors, with the advent of submarine warfare. Sonar works excellently in water, where sound travels far better than light or radio waves (more on that in a second). Sonar sensors are in active use on cars today, primarily in the form of parking sensors. These short-range (~5m) sensors enable a cheap way to know just how far that wall is behind your car. Sonar hasn’t been proven to work at the kinds of ranges a self-driving car demands (60m+).

In this instance, the Bat is the sender/receiver

Radar

Radar (radio direction and ranging), much like Sonar, was another technology developed during an infamous World War (WW2, this time). Instead of using light or sound waves, it instead utilizes radio waves to measure distance. We make use of a lot of Radar (using Delphi sensors) on Homer, and it’s a tried-and-tested method that can accurately detect and track objects as far as 200m away.

Radar has very little in terms of downside. It performs well in extreme weather conditions and is available at an affordable pricepoint. Radar is heavily used not only for detection of objects, but tracking them too (ex: understanding how fast a car is going and in which direction). Radar doesn’t necessarily give you granularity of LIDAR, but Radar and LIDAR are very complimentary, and it’s definitely not either/or.