Lidar (Light Detection and Ranging) is a remote sensing method that measures distance to targets by emitting rapid laser pulses and recording the time-of-flight of the backscattered signal to reconstruct three-dimensional spatial information. Operating typically in the near-infrared or ultraviolet-visible spectrum, lidar systems integrate a laser transmitter, scanning optics, timing electronics, and sensitive detectors (e.g., APDs, SPADs) to achieve centimeter- to meter-scale ranging precision. Methodological variants include airborne and terrestrial lidar for topographic mapping, bathymetric lidar using water-penetrating wavelengths, and Doppler lidar for wind profiling, with data processed into point clouds, digital elevation models, and other quantitative geospatial products.
Optical frequency combs, as a time and frequency "ruler," have important applications in precision ranging. Conventional dual-comb ranging schemes utilize the optical Vernier effect to achieve long-distance measurements, ...
Optics & Photonics
Aug 20, 2025
0
88
Canada is facing another dangerous wildfire season, with burning forests sending smoke plumes across the provinces and into the U.S. again. The pace of the 2025 fires is reminiscent of the record-breaking 2023 wildfire season, ...
Environment
Jul 28, 2025
0
36
Satellite data used by archaeologists to find traces of ancient ruins hidden under dense forest canopies can also be used to improve the speed and accuracy to measure how much carbon is retained and released in forests.
Ecology
Jun 14, 2025
0
41
Fluorescence lidar technology enables a better determination of the origin of particles in the atmosphere. The method can also visualize particle layers that were previously practically invisible. This is the conclusion drawn ...
Environment
Jun 4, 2025
0
19
In the United States, earthen levees are an integral part of flood control systems, protecting around 23 million Americans and crucial infrastructure. Recently, the American Society of Civil Engineers' 2025 Report Card for ...
Earth Sciences
Jun 3, 2025
0
30
Researchers from the University of Rochester and University of California, Santa Barbara, engineered a laser device smaller than a penny that they say could power everything from the LiDAR systems used in self-driving vehicles ...
Optics & Photonics
Jun 2, 2025
0
98
Since last fall, NASA scientists have flown an advanced 3D Doppler wind lidar instrument across the United States to collect nearly 100 hours of data—including a flight through a hurricane. The goal? To demonstrate the unique ...
Earth Sciences
Apr 28, 2025
0
28
With their ability to store carbon, forests are often considered the lungs of the Earth, but they are vulnerable to the world's ills, too. A new study, using NASA laser technology from the International Space Station, reveals ...
Environment
Apr 7, 2025
0
56
The frequency regime lying in the shortwave infrared (SWIR) has very unique properties that make it ideal for several applications, such as being less affected by atmospheric scattering as well as being "eye-safe." These ...
Optics & Photonics
Apr 3, 2025
0
106
Researchers have designed a single-photon time-of-flight LiDAR system that can acquire a high-resolution 3D image of an object or scene up to 1 kilometer away. The new system could help enhance security, monitoring, and remote ...
Optics & Photonics
Feb 6, 2025
3
2034
