LiDAR or Light Detection and Ranging (+Video)

Dear Mappers,

Inspired by our ADAS article we continue with a sort introduction of LiDAR systems.

LiDAR or Light Detection and Ranging is an active remote sensing system that can be used to make digital 3-D representations of the target. Remote sensing means that we aren’t actually physically measuring things with our hands. We are using sensors which capture information about a landscape and record things that we can use to estimate conditions and characteristics. To measure data across large areas, we need remote sensing methods that can take many measurements quickly, using automated sensors.

LiDAR is commonly used to make high-resolution maps, with applications in many fields such as geodesy, archaeology, geography, seismology .The technology is also used in control and navigation for some autonomous cars (as we mention to our blog post about ADAS).

So how does this technology work: LiDAR is an active remote sensing system. An active system means that the system itself generates energy – in this case, light – to measure things on the ground. In a LiDAR system, light is emitted from a rapidly firing laser. You can imagine light quickly strobing from a laser light source. This light travels to the ground and reflect off of things like buildings. The reflected light energy then returns to the LiDAR sensor where it is recorded.

A LiDAR system measures the time it takes for emitted light to travel to the ground and back. That time is used to calculate distance traveled. Distance traveled is then converted to elevation. These measurements are made using the key components of a LiDAR system including a GPS that identifies the X,Y,Z location of the light energy and an Internal Measurement Unit (IMU) that provides the orientation of the plane in the sky.

In that way a self-driving car, with the use of advanced control systems like LiDAR can interpret sensory information to identify appropriate navigation paths, as well as obstacles.

Curious how it looks in action – check the video below!