Introduction: What is LiDAR?
CC BY SA by Oregon State University
What is LiDAR?
Methods of detecting distance between objects have long existed in nature. Bats, for instance, use a form of sonar navigation called echolocation in order to detect both prey and obstacles. Man-made sonar was first introduced in the early twentieth century as a way to detect—and ultimately circumvent—icebergs.
Sonar, and later, more advanced radar detection has been used for a variety of nautical applications involving navigation over the last century. There are limitations to this technology, however. Today’s accelerated technology often requires expedient delivery of results, particularly when it comes to calculating distance and location. Given that, LiDAR—or light detection and ranging technology—is often an ideal solution. LiDAR is a method of measuring distance by sending out beams of light (in the form of a pulsed laser) in order to measure the distance range between a target and the laser source.
Though it works in much the same way as radar, LiDAR is one million times faster than the sound waves that are measured by sonar. In fact, according to researchers at Germany’s Karlsruhe Institute of Technology (KIT) and the Swiss Federal Institute of Technology Lausanne (EPFL) in Switzerland, LiDAR is faster than a speeding bullet.
LiDAR is also valued for its precision, which is why it has been used since the 1980s in conjunction with GPS technology to detect and measure the position and pathways of aircraft, a use case where accuracy is essential.
How does LiDAR work?
The technical explanation behind how LiDAR works is straightforward. Light is beamed at a target and then the time that light takes to return to the source is measured. Since light moves at a constant and known speed, a LiDAR instrument is able to measure the “Time of Flight,” or the distance between itself and its target with assurance. As these measurements are repeated, the device can then transmit that information to a computer that will construct a map of the area of data collection. These visual representations of measurements are known as “Point Cloud” maps. Unlike static two-dimensional maps, Point Cloud visualizations reveal complex spatial relationships in a readable format.
What are other common use cases for the technology?
In addition to being used in the airline industry, LiDAR technology has utility in other market sectors. LiDAR’s high rate of accuracy makes it ideal for geographical map creation—especially for difficult-to-access terrain such as mountain ranges or dense forest areas. The technology can be used in disaster recovery or search and rescue missions to locate target positions. LiDAR can also be used to survey coastlines and provide marine scientists with coastal erosion data in order to develop with mitigation and preservation plans.
Further, in densely populated areas, LiDAR can aid with urban planning by producing spatial models that might enable civil engineers to create digital city models that thoughtfully leverage land use by evaluating the built environment alongside population density. In addition to more traditional uses of LiDAR in measuring distance points, the technology can also be used to detect foreign particles (like microscopic sediment or natural gas) in water and air—which can be useful for checking pollution levels or contamination of sites.
LiDAR in the autonomous vehicle market
LiDAR technology is viewed as an integral component of autonomous vehicle hardware and one of the key elements that may undergird both its efficacy and market viability.
The German company Sick AG has developed LiDAR sensor units that help autonomous vehicles navigate traffic flow and roadway mergers. Current autonomous vehicles in the testing phase avoid collisions via a coordinated system of GPS, cameras, sensors, and LiDAR. Static GPS alone would not be fully effective for car because roadways are dynamic and constantly changing. Some self-driving car projects in development include Google’s prototype for Waymo. Waymo is equipped with LiDAR-enabled technology that allows these autonomous vehicles to detect “pedestrians, cyclists, vehicles, road work, and more from up to three football fields in all 360 degrees.”
Alongside various sensors, LiDAR technology helps to fill in the missing pieces that GPS alone cannot provide to construct a fully three-dimensional, responsive map. The autonomous vehicles’ onboard hardware then communicates with those maps and processes that data along with other information from established maps. This multi-layered process is what allows the vehicle to navigate efficiently and effectively—and LiDAR technology is at its core.