LIDAR is an acronym for light detection and ranging. It is an optical remote sensing technology used to examine the surface of the earth, often using pulses from a laser.

1. Presented By:
Narayan Lal Menariya
ECE 4th year
Presented To:
Prof. Yashvant Soni
ECE Department
TINJR , Udaipur

2.  Introduction.
 General Description
 Brief History.
 Basic Principle and Technique.
 How Lidar works.
 Lidar components
 Application
 Advantage.
 Disadvantage.
 Conclusion.

3.  LIDAR is an acronym for light detection
and ranging. It is an optical remote sensing
technology used to examine the surface of
the earth, often using pulses from a laser.
 NOAA(National Oceanic And Atmospheric
Administration) scientists use LIDAR-
generated products to examine both
natural and manmade environments.

4.  LIDAR is an active remote sensing technique , similar to radar but uses
laser light pulses instead of radio waves.
 Most LIDAR systems operate in near infra–red region of
electromagnetic spectrum (i.e , 1064 nm).
 LIDAR instruments can rapidly measure the earth’s surface at a
sampling rate greater than 150khz.The resulting product is a
densely spaced network of highly accurate georefrenced
elevation points –point cloud. It can be used to generate 3-D
representation of earth’s surface

5.  First laser based device was constructed by G.fiocco at MIT using a ruby
laser.
 The general public became aware of the accuracy and usefulness of LIDAR
systems in 1971 during the Apollo 15 mission
 Apollo 15 was the fourth mission to land men on the Moon.
 Its first applications came in meteorology, where the National Centre for
Atmospheric Research used it to measure clouds.
 Searchlights were used to measure the altitude of the clouds.
 Measurement was done by pointing a beam of light in sky and then
reading the angle at which the beam of light struck the cloud, on a device
that was known distance away from the searchlight. One was then able to
obtain height by triangulation.

6.  The basic idea is:
 Laser generates an optical pulse
 Pulse is reflected off an object and returns to the system
receiver.
 High-speed counter measures the time of flight from the start
pulse to the return pulse
 Time measurement is converted to a distance
 the distance to the target and the position of the target is then
used to determine the elevation and location

7. LASER
LIDAR
Scanner
And
Optics
LIDAR sensor and
photo detector
Position
and
Navigatio
n
System

8.  Airborne topographic mapping LIDAR’s
generally use 1064 nm diode
pumped YAG lasers, while
bathymetric(underwater depth
research) system generally uses 532 nm
frequency double diode pumped YAG
laser.
 532 nm penetrates water with much
less attenuation than does 1064 nm.
 Better target resolution is achieved with
shorter pulses.

9.  Neodymium ions in various
types of ionic crystals, and also
in glasses, act as a laser gain
medium, typically emitting
1064 nm light from a particular
atomic transition in the
neodymium ion, after being
"pumped" into excitation from
an external source
 Nd : Y3Al5O12
 Nd:YAG lasers are optically
pumped using a flashtube
or laser diodes.

10.  There are several options to scan the
azimuth and elevation:
 dual oscillating plane mirrors
 a combination with a polygon mirror and
a dual axis scanner
 A hole mirror or a beam splitter are
options to collect a return signal.
 Optic choices affect the angular
resolution and range that can be
detected

11.  The HDL-64E LIDAR sensor is
designed for obstacle detection and
navigation of autonomous ground
vehicles and marine vessels
 Its durability, 360 field view and
very high data rate makes this
sensor ideal for 3D mobile data
collection and mapping
applications.
 Two main photo detector
technologies are used in LIDAR’s:
 Solid State photo detectors such as
silicon avalanche photodiodes
 photomultipliers

12.  64 Channels
 120m range
 2.2 Million Points per Second
 360° Horizontal FOV
 26.8° Vertical FOV
 0.08° angular resolution (azimuth)
 <2cm accuracy
 ~0.4° Vertical Resolution
 User selectable frame rate
 Rugged Design

13.  LIDAR sensors that are mounted
on mobile platforms such as
airplanes or satellites uses two
techniques to determine the exact
position and orientation:
 Global Positioning System(GPS)
 Inertial Measurement
Unit (IMU)

14. AGRICULTURE :
 LIDAR sensors can detect the edges
of rows, so that farming equipment
can continue moving until GPS signal
is re-established.
 LIDAR can help determine where to
apply costly fertilizer by generating a
topographical map
 crop mapping: to detect foliage
growth, detect variations in fruit
production, or count plants.

15. Autonomous vehicles :
 use LIDAR for obstacle
detection and avoidance to
navigate safely through
environments
 Sick and Hokuyo example of
two companies produces
LIDAR sensor for autonomous
vehicle
 Uber self driving car with lidar
system on roof

16. Biology and conservation :
 forestry
 Canopy heights,
 biomass measurements
 and leaf area study
 the Save-the-Redwoods League is
undertaking a project to map the tall
redwoods on the Northern California
coast.

17. Law enforcement :
 LIDAR speed guns are used by the police to measure the speed of
vehicles for speed limit enforcement purposes
Military :
 nuclear cruise missile detection
 The Long-Range Biological Standoff Detection System (LR-BSDS) was
developed for the U.S. Army to provide the earliest possible standoff
warning of a biological attack
Physics and astronomy
Robotics

18.  The geometric features of the objects are extracted efficiently
 high point density and high spatial resolution
 Fast acquisition and Processing
 It can be implemented in real time and has been proven efficient if the
3-D occupancy grid size is considerably restricted
 Minimum human dependency
 usage of sensor with weather-robust head helps detecting the objects
even in bad weather conditions. Canopy Height Model before and after
flood is a good example.
 LIDAR systems provides better range and a large field of view which
helps detecting obstacles on the curves

19.  Precise alignment is required
 Very large datasets that are difficult to interpret and process.
 Although significant amount of research has been done for object classification
from 3-D point clouds, the direct extraction of individual points from LIDAR
inputs has not been achieved.
 Sometimes gives very minute elevation error.

20. Now a days LIDAR has become an efficient method to
detect the absolute azimuth and elevation position of
target. It function is very easy thus it is efficient to use and
now a days providing the application in military, robotics
and autonomous vehicle etc.

21.  Major help from Wikipedia : https://en.wikipedia.org/wiki/Lidar
 HDL-64E LIDAR sensor image:
 http://www.anpico.com/newsletter/2012/E1207113/1207113E.html
 Uber self driving car image:
 https://en.wikipedia.org/wiki/File:Uber_car_with_lidar.jpg
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