What is LiDAR
LiDAR, which stands for Light Detection and Ranging, is a remote sensing technology 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.
When a Mobile or Terrestrial LiDAR system is used, a laser is pointed at a targeted object on the earth’s surface and the beam of light is reflected back from the object it encounters. A sensor records this reflected light to measure a range. When laser ranges are combined with position and orientation data generated from integrated GPS and Inertial Measurement Unit systems, scan angles, and calibration data, the result is a dense, detail-rich group of elevation points, called a “point cloud.”
Each point in the point cloud has three-dimensional spatial coordinates (latitude, longitude, and elevation, and/or X, Y, and Z values depending on the application) that correspond to a particular point on the Earth’s surface from which a laser pulse was reflected. Point clouds can be used to generate geospatial products, such as digital elevation models, canopy models, building and roadway models, and may be used to create contour mapping.