Archaeological Survey of India (ASI) aims to conduct a Light Detection and Ranging (LiDAR) survey before excavations.
About LiDAR
A remote sensing technology that uses light in the form of a pulsed laser to measure ranges (distances) to a target. oSimilar to radar and sonar (that use radio and sound waves, respectively).
Types of LiDAR:
o Topographic LiDAR: uses a near-infrared laser to map the land.
o Bathymetric LiDAR: uses water-penetrating green light to also measure seafloor and riverbed elevations.
• Platforms used for acquiring data: Airplanes and helicopters.
Functioning of LiDAR • An airborne laser is pointed at a targeted area and beam of light is reflected by the surface it encounters. o A sensor records this reflected light to measure a range. • When laser ranges are combined with position and orientation data, a point cloud (group of elevation points) is created.
o Point cloud helps in generating coordinates corresponding to a particular point on the Earth's surface other geospatial products, such as digital elevation models, canopy models, building models, and contours. Conclusion LiDAR makes it easy to produce high resolution representation of elevations to estimate key characteristics and providing accurate geospatial measurements over large areas.
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