From Archeology to Autonomy, LiDAR Sweeps Industries
In the past month, LiDAR has made headlines in meteorology, archeology, and vehicle autonomy.
Shortly after the invention of the laser, Hughes Aircraft Company launched the first LiDAR system for satellite tracking in 1961.
In recent years, however, LiDAR development has been catalyzed by the growth of autonomous cars, resulting in smaller, more powerful, and more affordable LiDAR solutions than ever before. Beyond autonomous cars, LiDAR technology has found applications in a variety of use cases, from meteorology to archeology.
NASA Measures Snow Depth With LiDAR
LiDAR's first widespread applications were in meteorology. In particular, the National Center for Atmospheric Research often used LiDAR to monitor clouds and measure pollution. NASA still employs LiDAR for meteorological purposes, tracking global climate from space.
One historical challenge, however, has been measuring snow depth from space; conventional camera systems cannot provide much information about depth within an image. To address this problem, NASA scientists have turned to LiDAR. On April 20, 2022, a team of scientists announced a method to directly measure snow depth using LiDAR measurements from the Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2).
A new technique allows NASA to monitor ice depth using LiDAR. Image used courtesy of NASA
When a photon enters snow, it bounces around and is scattered until it is eventually collected again by the ICESat-2. Creating a model of this behavior, the researchers developed a unique equation that can find the average distance a photon travels inside the snow before it is eventually measured by the LiDAR. The depth of the snow is equal to half of that average distance.
Using this new technique, NASA scientists claim that ICESat-2 provides a more advanced monitoring solution and data about the impact of climate change on the ice caps.
LiDAR Uncovers Ancient Settlements
In late May, a group of researchers from the German Archeological Institute announced that they had used LiDAR technology to make an unexpected archaeological find in the Amazon.
Looking to uncover remnants of an ancient civilization in the Amazon, the team of researchers took LiDAR to the skies. The team equipped a helicopter with LiDAR sensors and subsequently flew over the rainforest and stretches of grassland. The laser pulses from the helicopter’s LiDAR were able to penetrate through the lush cover of the rainforest and provide the team with a detailed 3D map of what once existed within the forest beneath the trees.
Archaeologists used LiDAR to uncover unknown Amazonian civilizations. Image used courtesy of the German Archaeological Institute and Science News
In a paper published in Nature, the team described their unprecedented find: a low-density, interconnected urban settlement that existed in pre-Columbian times. Of the total of 26 settlements found by the LiDAR data, 11 of them were previously undiscovered. These findings have spurred researchers to reevaluate their understanding of ancient civilizations since such low-density urban sprawls were previously unknown in the Amazon or anywhere else in South America.
Moving forward, the team believes that excavations guided by LiDAR can reveal more archeological sites, particularly in hard-to-traverse terrains like rainforests.
New LiDAR Measures Velocity
One of LiDAR's most popular applications remains autonomous vehicles. Baraja, a LiDAR solutions company, recently showcased a new technology called Spectrum-Scan LiDAR on May 10, 2022. Spectrum-Scan LiDAR is described as the industry’s first per-point Doppler-capable LiDAR with the ability to measure the velocity of moving objects.
Sensors in a Baraja van detecting pedestrians. Image used courtesy of Baraja
While traditional LiDAR can estimate velocity on a frame-to-frame basis, Baraja uses random modulation continuous wave (RMCW), where the system extracts information encoded in the phase/frequency modulation of the wave to determine its velocity. This technique is also known as homodyne detection and allows Baraja’s technology to simultaneously measure the distance and velocity of an object.
With this fourth dimension added to LiDAR, Baraja claims its LiDAR can add more context to a 3D map and provide autonomous vehicles with a safer, more holistic driving experience.
LiDAR Moves Into Commercial Spaces
While LiDAR made its debut with aircraft companies and NASA, it is now so commonplace that it appears in iPhones for augmented reality. In fact, according to Allied Market Research, the worldwide LiDAR market—valued at $700.2 million in 2019—will jump to $2.90 billion by 2027.
Do you have hands-on experience with LiDAR systems? Share your experience in the comments below.