1. LIDAR(Light
Detection& Ranging)
BY:
p.sandeepkumar
092m1a04a1
BRANCH-ECE

2. INTRODUCTION
What is LIDAR ?
Remote sensing technology
Uses much shorter wavelength of EM spectrum
Measures properties of scattered light
Measures time delay between transmitted and
reflected signals
Highly sensitive to aerosols and cloud particles

3. BASIC PRINCIPLE OF LIDAR
In RADAR, radio waves are transmitted into the
atmosphere, which scatters some of the power back
to the Rader’s receiver.
A LIDAR also transmits & receives electro-magnetic
radiation and operate in the ultraviolet, visible and
infrared region of the electromagnetic spectrum. The
LIDAR is also popularly known as LASER RADAR.
A LIDAR basically consists of a transmitter, receiver &
detector

4. LIDAR vs. RADAR
LIDAR uses much shorter wavelength of UV, visible
and near IR range
LIDAR is highly sensitive to non-metallic objects
LIDAR has very narrow beam which produces high
resolution
This makes LIDAR a better choice for studying
weather patterns using small technology, which is
especially useful for studying distant atmospheres
through satellites orbiting around other planets.

5. LIDAR TYPES
 based on backscattering : Rayleigh LIDAR
 Mie LIDAR
 Raman LIDAR
Other types: Coherent LIDAR(phase sensitive)
 Incoherent LIDAR(amplitude measurement)

6. TECHNOLOGIES USED
Integration Of three technologies to produce Digital
Elevation Models(DEM)
They are: Lasers
 Global Positioning System(GPS)
 Inertial Navigation System(INS)

7. WORKING
Laser produces optical pulse
Pulse is transmitted , reflected and returned to the
receiver
Receivers accurately measures the travel time
X,Y,Z ground coordinates can be calculated using : Laser range
 Laser scan angle
 Laser Position from GPS
 Laser orientation from INS

8. LIDAR TECHNOLOGY

9. COMPONENTS
Laser:
 600-1000nm lasers used for non-scientific application
 Inexpensive
 Easily absorbed by eye
 1500nm lasers
 less advanced, longer range , lower accuracy
 Eye safe at much higher power level
 Used in military application

10. Contd…..
Scanner
Used to scan the objects , azimuth and elevation
 Uses : Dual oscillating plane mirror
 Dual axis scanner
Optics
 They affect angular resolution and range
 To Collect return signal it uses : Hole mirror
 Beam splitter

11. Contd…..
Photo detector and receiver electronic
 Solid state photo detectors
 Silicon avalanche photodiodes
Position and navigation systems
 Global Positioning System receiver
 Inertial Measurement Unit(IMU)

12. APPLICATIONS
LIDAR-equipped mobile robot
 Used for constructing map

13. Contd….
Meteorology and Atmospheric Environment
Used for studies of atmospherics conditions , structures ,
clouds and aerosols.
Used for measurement of atm. gas
Measures wind speed

14. Contd….
PHYSICS AND ASTRONOMY
Measure the distance to reflectors placed on the
moon
Used in Mars-Orbiting Satellite to produce precise
global topographic survey of Mars
Used to detect snow in Mars atmosphere
Used to measure molecular density

15. Contd….
MILITARY AND LAW ENFORCEMENT
Used in traffic speed enforcement for vehicle speed
measurement
Uses the principle of time of flight to calculate speed
Able to find the vehicle speed from cluster traffic
situation
Higher resolution system collect detail to identify
targets (tanks)

16. CAPTURE OF ELEVATION
POINTS
Collects only elevation data
GPS antenna is mounted on
upper fuselage
GPS sensors records the data
Data are downloaded and
processed
X,Y,Z coordinates are found

18. OTHER APPLICATIONS
FLOOD RISK MAPPING
Quickest and most accurate method to measure DEM
Easy flood prediction and plan mitigation and
remediation strategies

19. Contd….
OIL & GAS EXPLORATION SURVEYS
Provide high speed data acquisition and limit ground
intervention
Done using either a fixed wing or helicopter mounted
LIDAR system

20. Contd….
ENGINEERING/CONSTRUCTION SURVEY
Using DEM cut and fill quantities can be more precisely
estimated
Time delay between data acquisition and delivery is
very less
Air bourn LIDAR provide a cost effective and quick
surveys for real estate development

21. Contd….
TRANSMISSION LINE MAPPING
Calculating power line heights or sag under different
loads
 Inventory
 Tower Placement
 Height of underlying vegetation

22. ADVANTAGES&DISADVATAGES
Large information bandwidth and extremely high
angular resolution possibilities are some of the
advantages of LIDARs
 low efficiencies and atmospheric propagation
limitations are some of the disadvantages

23. CONCLUSION
It has allowed data to be collected that was difficult
or impossible to obtain prior to its introduction.
Data collection and its processing is relatively fast
LIDAR saves clients money
LIDAR offers flexibility
LIDAR is unobtrusive and environmentally friendly

24. REFERENCES
www.wikipedia.org
www.lidar.com
www.ambercore.com
www.gisdevelopment.net
www.lidarmap.org
www.velodyne.com/lidar/

25. THANK YOU