LIDAR(Light Detection& Ranging)

BY: p.sandeepkumar 092m1a04a1

BRANCH-ECE

INTRODUCTION

What is LIDAR ?Remote sensing technologyUses much shorter wavelength of EM

spectrumMeasures properties of scattered light Measures time delay between transmitted

and reflected signalsHighly sensitive to aerosols and cloud

particles

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

BASIC PRINCIPLE OF LIDAR

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.

LIDAR vs. RADAR

based on backscattering :- Rayleigh LIDAR Mie LIDAR Raman LIDAR

Other types:- Coherent LIDAR(phase sensitive) Incoherent LIDAR(amplitude

measurement)

LIDAR TYPES

Integration Of three technologies to produce Digital Elevation Models(DEM)

They are:- Lasers Global Positioning System(GPS) Inertial Navigation System(INS)

TECHNOLOGIES USED

Laser produces optical pulsePulse is transmitted , reflected and returned to

the receiverReceivers accurately measures the travel timeX,Y,Z ground coordinates can be calculated

using :- Laser range Laser scan angle Laser Position from GPS Laser orientation from INS

WORKING

LIDAR TECHNOLOGY

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

COMPONENTS

ScannerUsed to scan the objects , azimuth and

elevationUses :-

Dual oscillating plane mirror Dual axis scanner

Optics They affect angular resolution and range To Collect return signal it uses :-

Hole mirror Beam splitter

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)

Contd…..

LIDAR-equipped mobile robot Used for constructing map

APPLICATIONS

Meteorology and Atmospheric EnvironmentUsed for studies of atmospherics conditions ,

structures , clouds and aerosols.Used for measurement of atm. gasMeasures wind speed

Contd….

PHYSICS AND ASTRONOMYMeasure the distance to reflectors placed on

the moonUsed in Mars-Orbiting Satellite to produce

precise global topographic survey of MarsUsed to detect snow in Mars atmosphereUsed to measure molecular density

Contd….

MILITARY AND LAW ENFORCEMENTUsed in traffic speed enforcement for vehicle

speed measurementUses the principle of time of flight to

calculate speedAble to find the vehicle speed from cluster

traffic situationHigher resolution system collect detail to

identify targets (tanks)

Contd….

CAPTURE OF ELEVATION POINTS

Collects only elevation dataGPS antenna is mounted on upper fuselageGPS sensors records the dataData are downloaded and processedX,Y,Z coordinates are found

FLOOD RISK MAPPINGQuickest and most accurate method to

measure DEMEasy flood prediction and plan mitigation and

remediation strategies

OTHER APPLICATIONS

OIL & GAS EXPLORATION SURVEYSProvide high speed data acquisition and limit

ground interventionDone using either a fixed wing or helicopter

mounted LIDAR system

Contd….

ENGINEERING/CONSTRUCTION SURVEYUsing DEM cut and fill quantities can be more

precisely estimated Time delay between data acquisition and

delivery is very lessAir bourn LIDAR provide a cost effective and

quick surveys for real estate development

Contd….

TRANSMISSION LINE MAPPINGCalculating power line heights or sag under

different loads Inventory Tower Placement Height of underlying vegetation

Contd….

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

ADVANTAGES&DISADVATAGES

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 moneyLIDAR offers flexibilityLIDAR is unobtrusive and environmentally

friendly

CONCLUSION

www.wikipedia.orgwww.lidar.comwww.ambercore.comwww.gisdevelopment.netwww.lidarmap.orgwww.velodyne.com/lidar/

REFERENCES

THANK YOU