lidar-technology

Context:

Recently, Apple has launched iPad pro which is the first device to use Lidar scanner.

About Lidar technology: 

  • LiDAR stands for light detection and ranging. 
  • LiDAR was first used on a spacecraft during the Apollo 15 mission in 1971, when astronauts mapped the surface of the moon.
  • It is basically a remote sensing method that uses light in the form of a pulsed laser to measure distances to the subject. 
  • A LiDAR sensor fires off beams of laser light and then measures how long it takes for the light to return to the sensor.
  • The basic mechanism is known as “time of flight” measurement in which a laser beam is emitted towards an object, reflected off of the object and then collected in a sensor located within the LiDAR module. 
  • Provide more information: These light pulses – when combined with other data, generate accurate, high-resolution three-dimensional information of the object.

SONAR and RADAR : Sonar and Radar too can reveal information about an object’s shape, size, direction and height.

  • SONAR : Sonar (short for sound navigation and ranging) relies on sound waves to detect objects and hence is usually used to detect objects underwater. 
  • Radio waves: Radar (short for radio detection and ranging) uses radio waves to determine an object’s distance or range. 
  • Radio waves can work over a long distance and perform better in dusty conditions, in this sense it is better than SONAR.

How is Lidar better?

  • Radar can plot the location of a vehicle from miles away, the location can only be known as a featureless “blip”.
  • The laser precision of LiDAR can visually map individual features of a vehicle or an environment in what is known as a “point cloud,”.
  • The LiDAR sensor provides continuous 360 degrees of visibility and accurate depth information.

Application of lidar technology:

  • LiDAR is used to collect high-density data in order to produce high-resolution maps.
  • Ground based surveys and aerial surveys: 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.

Disadvantage of LiDAR:

  • LiDAR can measure the distance to surrounding objects up to 5 meters away, but won’t fare well in identifying objects in the vicinity.
  • It can’t perform well in fog, rain, snow and dusty weather.
  • Need secondary cameras: LiDAR also struggles to detect a glass wall or door, which is why smartphone manufacturers and self-driving cars makers use LiDAR along with secondary cameras and sensors.