Note4Students
From UPSC perspective, the following things are important :
Prelims level: LiDAR technology,
Mains level: Use of technology in infrastructure
Why in the News?
Scientists have used LiDAR technology to find an ancient Mayan city hidden for centuries under a thick jungle in Mexico.
What is LiDAR?
- LiDAR (Light Detection and Ranging) is a remote sensing technology that uses laser light pulses to measure distances between a sensor (often airborne) and Earth’s surface.
- It produces high-resolution, 3D models of ground elevation with up to 10 cm vertical accuracy, as per the US Geological Survey.
How Does LiDAR Work?
- LiDAR Setup: Includes a laser, a scanner, and a GPS receiver. The laser emits rapid pulses of light that reflect off surfaces on the ground, including natural features and man-made structures.
- Data Collection: The reflected light returns to the sensor, and the LiDAR system calculates the two-way travel time to determine the distance to each point on Earth’s surface.
- Data Processing: GPS and Inertial Measurement System (IMS) data are used to create accurate maps. The initial data forms a “point cloud” representing surfaces like vegetation, buildings, and terrain.
- “Bare Earth” Model: By filtering out structures and vegetation, LiDAR can create a Digital Elevation Model that shows just the ground terrain.
Applications of LiDAR
- Geography and Mapping: Creates precise 3D information for topographic mapping.
- Urban Planning and Infrastructure: Used in planning transportation routes, assessing flood risk, and managing natural resources.
- Conservation: Helps monitor forest health, manage habitats, and detect environmental changes.
- Engineering and Policy: Provides data for infrastructure design, environmental policy making, and land-use planning.
Why is LiDAR Useful for Archaeologists?
- Large-Area Surveying: LiDAR enables archaeologists to study extensive areas quickly, bypassing the need for labor-intensive, on-ground exploration.
- Vegetation Penetration: LiDAR can “see through” dense tree canopies by using the reflections that pass through gaps, allowing mapping of hidden structures and terrain.
- Detailed Site Mapping: With “bare earth” models, archaeologists can strip away vegetation layers to reveal hidden archaeological sites.
- Case Study – Maya Civilization: Archaeologists discovered the lost Mayan city of Valeriana in Mexico by analyzing publicly available LiDAR data, uncovering plazas, temple pyramids, a ballcourt, and other features indicative of a Classic Maya capital.
Where is the Indian Government using LiDAR ?
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Conclusion: LiDAR technology has revolutionized fields from archaeology to urban planning by providing precise 3D mapping. In India, it’s enhancing infrastructure projects, environmental monitoring, and urban planning, proving invaluable for efficient, large-scale data collection and analysis.
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