About

• Lidar, which stands for Light Detection and Ranging, is a remote sensing method that uses light in the form of a pulsed laser to measure ranges (variable distances) to the Earth.
• These light pulses—combined with other data recorded by the airborne system — generate precise, three-dimensional information about the shape of the Earth and its surface characteristics.
• A lidar instrument principally consists of a laser, a scanner, and a specialized GPS receiver.
• There are two types of lidar: topographic and bathymetric. 
  • Topographic lidar typically uses a near-infrared laser to map the land, while 
  • bathymetric lidar uses water-penetrating green light to also measure seafloor and riverbed elevations

Applications of LIDAR:

• LiDAR is unique in its ability to measure the vertical structure of forest canopies. 
• It has the ability to detect particles in both water and air. Pollutants such as carbon dioxide, sulphur dioxide and methane are all detectable with LiDAR. 
• With the ability to collect large areas of high-resolution data in a relatively short space of time, LiDAR provides the perfect data for cellular network planning. 
• LiDAR sensors are being fitted under drones to create readings of the terrain, transmission lines, buildings, and trees.
• LiDAR is currently being used to provide 3D maps of the ground beneath.

Why in News?

National High Speed Rail Corporation Limited will be adopting Light Detection and Ranging Survey (LiDAR) technique using Laser enabled equipment mounted on a Helicopter for conducting ground survey for the preparation of Detailed Project Report for the proposed Delhi-Varanasi High Speed Railway corridor.

References:

1. https://www.pib.gov.in/PressReleasePage.aspx?PRID=1678878
2. http://www.lidar-uk.com/usage-of-lidar/
3. https://oceanservice.noaa.gov/facts/lidar.html