What is LiDAR?

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What is LiDAR? Blog Image


A huge city hidden by the luxuriant vegetation of the Amazon rainforest was recently discovered in Ecuador by a LiDAR survey.

About LiDAR

  • 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. 
  • Airplanes and helicopters are the most commonly used platforms for acquiring lidar data over broad areas.
  • How Does it Work?
    • A LiDAR system calculates how long it takes for beams of light to hit an object or surface and reflect back to the laser scanner.
    • The distance is then calculated using the velocity of light. These are known as ‘Time of Flight’ measurements. 
  • Two types of lidar are 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.
  • Lidar systems allow scientists and mapping professionals to examine both natural and man-made environments with accuracy, precision, and flexibility. 
  • It is used in a wide range of land management and planning efforts, including hazard assessment (including lava flows, landslides, tsunamis, and floods), forestry, agriculture, geologic mapping, and watershed and river surveys.
  • What is the difference between Radar and LiDAR?
    • LiDAR works in a similar way to Radar and Sonar yet uses light waves from a laser, instead of radio or sound waves.

Q1) What is a Radar?

The word radar comes from the acronym radio detection and ranging. As the name implies, radars use radio waves to determine the distance and velocity of the targets they hit. A radar system usually consists of a transmitter to send out radio signals and a receiver to catch any reflected energy from targets.

Source: 3,000-Year-Old City Hidden In Amazon Rainforest Discovered