What is LiDAR?

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.

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