Light detection and ranging technology
OUTLINE
Introduction
LIDAR : what???
why???
how???
Ranging of LIDAR
Components
Basic principle of operation
Traditional photography Vs LIDAR
Advantages & Disadvantages of LIDAR
Application
Conclusion
References
What is lidar???
Light detection and ranging(LIDAR) is an optical Remote Sensing Technology that can measure the distance to an object or surface.

It is similar to Radar, but it incorporates laser pulses rather than radio waves.
Why lidar???
LIDAR uses Ultraviolet, Visible or near Infrared light to image objects and can be used with a wide range of targets, including non metallic objects, rocks , rain, chemical compounds, aerosals, clouds and even single molecules.

A narrow laser beam can be used to map physical features with very high resolution.
How???
It works similar to RADAR.
Each time the LASER(Light Amplification by Stimulated Emission of Radiations) generates an optical pulse.
This 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.
Ranging of lidar
LIDAR systems can emit pulses at rate > 1,00,000 pulses per second referred to as Pulse Repetition Frequency.
A pulse of laser light travels at ‘C’, the speed of light.
The travelling time of a pulse of light ‘t’ is
t = 2( R/C )
components
LASER

SCANNER AND OPTIC

PHOTODETECTOR AND RECEIVER

POSITION AND NAVIGATIONAL SYETEM
LASER
600-1000 nm Laser are most common for non- scientific applications.
Air borne topographic mapping lidars generally use 1064 nm diode pumped YAG Lasers.
Better target resolution is achieved with shorter pulses, provided the Lidar Receiver Detector and electronics have sufficient bandwidth.