This article was updated July 2023.
Sensors are increasingly being utilized in several key industries in the 21st century. This article will discuss the history, function, and applications of the LiDAR sensor.
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The Origins of the LiDAR Sensor
LiDAR sensors originated in the 1960s, when LiDAR was created shortly after the advent of lasers. First developed by the Hughes Aircraft Company in 1961, the National Center for Atmospheric Research in the US used LiDAR to measure clouds and pollution soon after that.
Some of the first major applications of LiDAR sensors and technologies were in the military and space industry in the 1960s and 1970s. In 1971, astronauts on NASA’s Apollo 15 mission used laser altimeters to map the surface of the moon successfully.
Originally, the technology was termed Colidar (Coherent light detection and ranging.) Early Colidar systems were the basis for all LiDAR systems, laser rangefinders, and laser altimeters. Today, LiDAR sensors are used by multiple industries to produce highly accurate maps and to enhance the sensing abilities of vehicles.
How Does a LiDAR Sensor Work?
LiDAR sensors utilize ultraviolet (UV), visible or near-infrared (IR) light to image objects and map their physical features. Several measurements are taken in quick succession to yield a complex map of the surface at high resolution.
A LiDAR sensor can target several material types, such as rocks, metallic and non-metallic objects, clouds, chemical compounds, rain, aerosols, and even single molecules. LiDAR sensors can “cut through” heavy tree cover to target and image hidden features not visible to the naked eye alone.
LiDAR sensors measure the distance to a target using active sensors, which emit an energy source for illumination instead of relying on sunlight. It fires rapid pulses of laser light, usually IR, at a surface – anything up to 150,000 pulses a second – to map land or water-penetrating green light to measure the seafloor or riverbeds.
When the light hits the target object, it is reflected back to a LiDAR sensor which measures the time taken for the pulse to bounce back from the target. The distance to the object is then accurately calculated, providing three-dimensional spatial data.
Applications of LiDAR Sensors
LiDAR sensors have applications. By using a LiDAR sensor, systems and scientists can gain highly accurate information about a surrounding environment. Some of the key applications of LiDAR sensors are listed below.
LiDAR Sensors and Self-Driving Vehicles
Self-driving, autonomous vehicles have been the focus of research and investment by companies such as Google, Uber, and Tesla. The first use of LiDAR in vehicles was in the early 2000s, with industry challenges such as the Grand DARPA Challenge exploring its potential for the civilian and military markets.
Notable progress has been made in employing LiDAR sensors in self-driving vehicles over the past decade. LiDAR sensors exist in units consisting of a laser, scanner, optics, and a specialized GPS receiver to give continuous 360o visibility and precise, in-depth information about the distance to objects and people to an accuracy of ±2cm.
Current LiDAR sensors in autonomous vehicles are not without their pitfalls, however. A number of highly publicized accidents involving self-driving vehicles have been reported in recent years.
Increasingly sophisticated LiDAR sensors are improving safety for drivers, pedestrians, and cyclists; however, improvements still need to be made to detect and track objects and accurately measure their speed and direction.
LiDAR Sensors and Archaeology
Throughout human history, civilizations have emerged and disappeared, leaving behind very few traces of their existence or in hard-to-reach environments. Many ancient cities and ceremonial palaces have been taken over by nature, hidden in vast forested areas such as the Amazon basin and Cambodia.
LiDAR sensors are ideally suited to the purposes of archaeologists as they can penetrate dense tree cover and reveal hidden structures that have not been seen for centuries. Systems are used in airplanes flying over target areas of interest.
LiDAR sensors have already been used to reveal more than 60,000 hidden ruins from the Maya civilization in Guatemala, mapping 810 square miles of houses, highways, palaces, and defensive fortifications, revealing a vast hidden metropolis that may have been home to millions more people than previously thought.
LiDAR Sensors and Construction
LiDAR sensors are employed in the construction industry to ensure that projects are on schedule and meet stringent quality standards. Real-time accurate 3D mapping detects construction defects earlier than conventional methods, saving time and money for building projects.
LiDAR Sensors and Underwater Surveying
Bathymetric LiDAR sensors use green wavelength light to reveal underwater features and structures, similar to bathymetric sonar surveying.
LiDAR Sensors For Atmospheric Studies
Several techniques, such as Doppler LiDAR, Raman LiDAR, and Differential Absorption LiDAR have been developed for atmospheric studies. A LiDAR sensor is often used to measure wind speed, water vapor, aerosols, and ozone.
Mapping Climate Change and Land Use with LiDAR Sensors
Satellite and airplane-based LiDAR sensor systems have been widely employed to measure sea ice levels, changing urban land use, pollution, and forest and biodiversity loss, providing crucial information on how human activity is affecting the climate and environment.
Mobile LiDAR: Managing Assets in Real Time
Cities and urban planners are utilizing mobile LiDAR sensor systems to produce geospatial databases to monitor, analyze, and manage infrastructure assets such as roads, bridges, utilities, and street signs. These systems are powerful tools for city managers.
LiDAR Sensors: The Future
A LiDAR sensor uses light to produce highly accurate real-time maps and data for multiple key applications such as weather and climate monitoring, surveying, and self-driving vehicles. As more sophisticated systems are developed, LiDAR will continue to play a central role in multiple industries over the coming years.
References and Further Reading
English, T (2020) What Is LiDAR Technology and What Are Its Main Applications? [online] interestingengineering.com. Available at: https://interestingengineering.com/science/what-is-lidar-technology-and-what-are-its-main-applications
GISGeography (2022) 15 LiDAR Uses and Applications [online] gisgeography.com. Available at: https://gisgeography.com/lidar-uses-applications/
Woodward, A (2023) Vast Maya Kingdom Is Revealed in Guatemalan Jungle [online] The Wall Street Journal. Available at: https://www.wsj.com/articles/vast-maya-kingdom-is-revealed-in-guatemalan-jungle-11675082088