L
LIGHT DETECTION AND RANGING (LIDAR)
Michael J. Starek
Harte Research Institute for Gulf of Mexico Studies,
Texas A&M University, Corpus Christi, TX, USA
Synonyms
Airborne laser scanning; Airborne laser swath mapping;
Airborne laser terrain mapping; Laser altimetry; Laser
radar; Laser ranging
Definition
Light detection and ranging (lidar) is an active sensing
technology that pulses a laser and records the energy
reflected from a distant object to measure its distance.
The basic principle of operation is analogous to radar
except it uses laser light energy instead of radio waves.
Description
Lidar systems consist of a laser transmitter and a receiver to
collect the reflected energy. By precisely measuring the
round-trip time of travel of the laser pulse as it propagates
from the laser transmitter to the object and back, the range
from the lidar sensor to the object can be accurately determined (Figure 1). For surveying and mapping purposes,
lidar systems typically include a scanning mechanism, such
as an oscillating mirror, to direct the laser pulse and image a
scene (Shan and Toth, 2009). Lidar mapping systems are
often mounted in mobile platforms, such as an airplane
(commonly referred to as airborne lidar), to scan large areas.
Range measurements for each laser pulse are integrated
with measurements of the platform’s position and orientation along with the scanning angle at the time of the pulse
to derive three-dimensional, geo-referenced coordinates
(positions) of points on the surface. The end product of
a lidar mapping survey is a point cloud of irregularly spaced
x,y,z values providing a 3D representation of the scanned
M.J. Kennish (ed.), Encyclopedia of Estuaries, DOI 10.1007/978-94-017-8801-4,
© Springer Science+Business Media Dordrecht 2016
LIGHT DETECTION AND RANGING (LIDAR)
Michael J. Starek
Harte Research Institute for Gulf of Mexico Studies,
Texas A&M University, Corpus Christi, TX, USA
Synonyms
Airborne laser scanning; Airborne laser swath mapping;
Airborne laser terrain mapping; Laser altimetry; Laser
radar; Laser ranging
Definition
Light detection and ranging (lidar) is an active sensing
technology that pulses a laser and records the energy
reflected from a distant object to measure its distance.
The basic principle of operation is analogous to radar
except it uses laser light energy instead of radio waves.
Description
Lidar systems consist of a laser transmitter and a receiver to
collect the reflected energy. By precisely measuring the
round-trip time of travel of the laser pulse as it propagates
from the laser transmitter to the object and back, the range
from the lidar sensor to the object can be accurately determined (Figure 1). For surveying and mapping purposes,
lidar systems typically include a scanning mechanism, such
as an oscillating mirror, to direct the laser pulse and image a
scene (Shan and Toth, 2009). Lidar mapping systems are
often mounted in mobile platforms, such as an airplane
(commonly referred to as airborne lidar), to scan large areas.
Range measurements for each laser pulse are integrated
with measurements of the platform’s position and orientation along with the scanning angle at the time of the pulse
to derive three-dimensional, geo-referenced coordinates
(positions) of points on the surface. The end product of
a lidar mapping survey is a point cloud of irregularly spaced
x,y,z values providing a 3D representation of the scanned
M.J. Kennish (ed.), Encyclopedia of Estuaries, DOI 10.1007/978-94-017-8801-4,
© Springer Science+Business Media Dordrecht 2016