1.
College of Natural and Computational Science
Department Of Physics
Seminar title:
Application of LASER for Satellite Remote Sensing
By: Solomon Zerihun
14/04/2009 E.C

2.
Outline
• Introduction to Laser
• Working Principle of Laser
• Application of Laser
• Introduction about satellite
• Application of satellite
• Remote sensing
• Application of remote sensing
• Summary

3.
The basic scientific principle behind
a laser was first put forward by DR.
charles H.townes in 1954. The
efforts of several scientists laser led
to the development of the first
laser called pulsed laser in 1960.
The process which makes lasers
possible, Stimulated Emission, was
proposed in 1917 by Albert Einstein

4.
Principle of laser action
• The interaction of light with matter involves
three processes:
 Photon absorption,
 Spontaneous emission and
 Stimulated emission.
Consider a simple two level energy system
having the lower and higher energy levels with
populations.
06/06/2015 DDU

5.
Two level system
absorption Spontaneous
emission
Stimulated
emission
hn hn
hn
E1
E2
E1
E2
hn =E2-E1

6.
Inter Action of atom with EM Radiation
Absorption of Radiation
Before Absorption

7.
Laser Construction

8.
Flashlight
Light
bulb
Laser
Light
bulb
Flashlight
Laser
Rays: Waves:

9.
Applications of Lasers and Photonics
• Industrial
• Medical
• Commercial
• Agricultural
Pesticide Concentration,
Drought,
• Quality control of
products
• Remote sensing
• Communication Energy
• Spectroscopy
• Problems in Physics
• Isotropy of space
• Gravitational wave
detection,
• Standardization of
Meter,
• Distance Measurement
High Power Lasers
10/10/2017 Dire Dawa University 10

10.
Laser printer Laser pointer
Laser: everywhere in your life

11.
THE COUNTING OF ATOMS IN
A SUBSTANCE BECAME
POSSIBLE BECAUSE OF
LASER.
IN COMPUTERS, LASERS ARE
USED TO RETRIEVE STORED
INFORMATION FORM A
COMPACT DISC(CD)

12.
LASERS ARE USED IN
FIBRE-OPTIC
ENDOSCOPE TO DETECT
ULCERS IN THE
INTESTINES.
LASERS ARE USED FOR
BLOODLESS SURGERY.

13.
Entertainment

14.
Military

15.
NOWADAYS, WE CAN FLY A PLANE WITH THE HELP OF
LASER RAYS. MAN HAS INVENTED TO FLY A PLANE
WITHOUT USING ANY FUEL.
LASER IS USEFUL TO MANKIND IN MANY WAYS. IN
FUTURE, MANY UNBELIEVABLE THINGS ARE GOING
TO HAPPEN WITH THE USE OF LASER RAYS.

16.
LASER ARE USED IN SPACE COMMUNICATION, IN
RADARS AND IN SATELLITES.

17.
Laser end

18.
What is a Satellite?
• Satellite: In astronomical terms, a satellite is
a celestial body that orbits around a planet.
– Example: The moon is a satellite of Earth.
• In aerospace terms, a satellite is a space
vehicle launched by humans and orbits around
Earth or another celestial body.

19.
Circular Motion
• Artificial satellites travel around
Earth in almost circular path
• An object moving in a circular
path is accelerating because it is
constantly changing direction

20.
Satellite Motion
• Gravity continuously
changes its direction
• The speed required to
keep a satellite in
orbit is 7,900m/s

21.
History of satellite communication
• 1945 Arthur C. Clarke publishes an essay about
„Extra Terrestrial Relays“
• 1960 first reflecting communication satellite ECHO
• 1963 first geostationary satellite SYNCOM
• 1965 first commercial geostationary satellite
• 1976 three MARISAT satellites for maritime
communication
• 1982 first mobile satellite telephone system
INMARSAT-A
• 1998 global satellite systems for small mobile
phones
.......

22.
Applications
 Traditionally
– weather satellites
– radio and TV broadcast satellites
– military satellites
– satellites for navigation and localization (e.g., GPS)
 Telecommunication
– global telephone connections
– backbone for global networks
– connections for communication in remote places or
underdeveloped areas
– global mobile communication

23.
24
Satellite orbits

24.
Satellite categories
Low Earth Orbit (LEO)
 Medium Earth Orbit (MEO)
 Geosynchronous Orbit (GEO)
GEO: EXACTLY 22 238 miles
MEO: typically around 8000 miles
HEO:var.
LEO: typically between 500 and 1000 miles

25.
26
Satellite orbit altitudes

26.
GEO Satellites
• Altitude: ~35.786 km.
• One-way propagation delay: 250-280 ms
• 3 to 4 satellites for global coverage
• Mostly used in video broadcasting
– Example: TURKSAT satellites
• Another applications: Weather forecast, global
communications, military applications
• Advantage: well-suited for broadcast services
• Disadvantages: Long delay, high free-space attenuation
27

27.
MEO Satellites
• Altitude: 10.000 – 15.000 km
• One-way propagation delay: 100 – 130 ms
• 10 to 15 satellites for global coverage
• Infrequent handover
• Orbit period: ~6 hr
• Mostly used in navigation
–GPS, Galileo, Glonass
• Communications: Inmarsat, ICO
28

28.
LEO Satellites
• Altitude: 700 – 2.000 km
• One-way propagation delay: 5 – 20 ms
• More than 32 satellites for global coverage
• Orbit period: ~2 hr
• Applications:
– Earth Observation
• GoogleEarth image providers (DigitalGlobe, etc.)
• RASAT (First satellite to be produced solely in
Turkey)
– Communications
• Globalstar, Iridium
29

29.
If we relate with Earth's Atmosphere

30.
Satellite end

31.
What is remote sensing?
• Remote Sensing: is the collection of
information relating to objects without being in
physical contact with them. Thus our eyes and
ears are remote sensors, and the same is true
for cameras and microphones and for many
instruments used for all kinds of applications

32.
cont,
• The science (and art) of acquiring
information about an object, without
entering in contact with it, by sensing and
recording reflected or emitted energy and
processing, analyzing, and applying that
information.

33.
Cont,
In remote sensing on our source of light we may
have
• Transmittance,
• Scattering and
• Absorption

34.
Applications of Remote Sensing
There are probably hundreds of applications - these are
typical:
• Meteorology - Study of atmospheric temperature,
pressure, water vapor, and wind velocity.
• Oceanography: Measuring sea surface temperature,
mapping ocean currents, and wave energy spectra and
depth sounding of coastal and ocean depths
• Geology- Identification of rock type, mapping faults
and structure.
• Geodesy- Measuring the figure of the Earth and its
gravity field.

35.
Cont,
• Agriculture Monitoring the biomass of land vegetation
• Forest- monitoring the health of crops, mapping soil moisture
• Botany- forecasting crop yields.
• Hydrology- Assessing water resources from snow, rainfall and
underground
• Disaster warning and assessment - Monitoring of floods and
landslides,
• monitoring volcanic activity, assessing damage zones from
natural disasters.

36.
Cont,
• Planning applications - Mapping ecological zones,
monitoring deforestation,
• monitoring urban land use.
• Oil and mineral exploration- Locating natural oil seeps and
slicks, mapping
• geological structures, monitoring oil field subsidence.
• Military- developing precise maps for planning, monitoring
military
• infrastructure, monitoring ship and troop movements
• Space program- is the backbone of the space program
• Seismology: as a premonition.

37.
Types Remote Sensing System
Visual remote sensing system

38.
Optical Remote Sensing

39.
Infrared Remote Sensing

40.
Microwave Remote Sensing

41.
Airborne Remote Sensing

42.
Radar Remote Sensing

43.
Satellite Remote Sensing
"eyes in the sky"

44.
Types Satellite Remote Sensing
• There are two main types of remote sensing:
Passive remote sensing
and
Active remote sensing.
What makes Passive and Active is the source of light !!!!

45.
• The sun is a source of energy or radiation,
which provides a very convenient source of
energy for remote sensing. The sun's energy is
either reflected, as it is for visible wavelengths,
or absorbed and then reemitted, as it is for
thermal infrared wavelengths.

46.
Passive

47.
• Passive sensors detect natural radiation that is
emitted or reflected by the object or
surrounding area being observed. Reflected
sunlight is the most common source of
radiation measured by passive sensors.
Examples of passive remote sensors include
film photography, infrared, and radiometers.

48.
Active

49.
Active remote sensing, on the other hand, emits
energy in order to scan objects and areas where
upon a sensor then detects and measures the
radiation that is reflected or backscattered from
the target.
RADAR is an example of active remote sensing
where the time delay between emission and return
is measured, establishing the location, height,
speeds and direction of an object.

50.
Remote sensing end

51.
Summary
Correlations
• During night time we may have not
natural source of light. So for this
time we have to use man made
source of light. From those LASER is
the only best solution to use as a
source

52.
Energetic Laser Should have on the satellite

53.
Active

54.
So
LASER is BEST!!!

55.
አመሰግናለሁ::
Thanks

56.
Questions Well Come