remote sensing and gps techniques

1. REMOTE SENSING
GPS TECNIQUES VIJAY .S
MSFBI1521
BHARATHIDASAN UNIVERSITY
DEPT OF BIOINFORMATICS

2. Global Positioning System

3. HISTORY
In 1956 the American physicalist
Friedwardt winterberg proposed a test of
general relativity which was used in the
design of GPS.
The US began the project of GPS in 1973
to overcome the limitations of previous
navigation system.
In 1978 the first experimental BLOCK-1
GPS satellite was launched.

5. What is GPS ?
A very precise positioning system
• Developed and maintained by the US
Department of Defense (DOD)
• Satellite Based
* 24 satellites
* 20,200 km high orbit

6. BUT!
Although it is a very precise
geographic positioning system
•It is very easy to get youself into trouble
•Why?
•Because you (probably) don’t understand
how it works
•And that leads to garbage

7. Characteristics of GPS
• Free
• Precise
• Reliable
• Anytime & anywhere
• All weather
• Unlimited user capacity

13. How GPS Works ………
Uses measurements from 4+ satellites
Distance = travel time x speed of light

14. GPS Receivers

15. Methods of data collection
Three methods of positioning
• Autonomous
10-20 meters
• Differential
2-5 meters
• Phase Differential
centimeter
2-5m10-20 m
cm

16. How accurate is GPS?
Depends on some variables
• Design of receiver
• Relative positions of satellites, often
known as DOP (Dilution of Precision)
• Postprocessing
• Time spent on measurement

18. REMOTE SIENSING

19. What is remote sensing used for?
Remote sensing is a method for getting information
about of different objects on the planet, without any
physical contacts with it.
Image Source: cimss.ssec.wisc.edu

22. Elements of Remote Sensing
Source:staff.aub.edu.lb

25. Satellite pictures
Satellite imagery consists of
photographs from which
collected by satellites.
Image Source: www.wonderwhizkids.com
Image Source: www.loneotaku.net
Japan Satellite View

26. Satellites offer a Global View
What does satellite image give you?
-Information on land cover, land use, habitats and
infrastructure
-multiple engagements by time series
-Mapping and monitoring changes and predict future

27. Application of Remote Sensing
Urbanization & Transportation
• Urban planning
• Roads network and transportation
planning
• City expansion
• City boundaries by time
• Wetland delineation
Image source: www.ldeo.columbia.edu
Image source: www.geospectra.net

28. Satellite image of deforestation
 Wageningen UR 2002

29. Types of Satellites
Geostationary
Satellites
A geostationary satellite is one
of the satellites which is getting
remote sense data and
located satellite at an altitude of
approximately 36000 kilometres
and directly over the equator.
Image Source: cimss.ssec.wisc.edu

30. Polar-Orbiting
Satellites
A polar orbit is a satellite
which is located near to
above of poles. This
satellite mostly uses for
earth observation by time.
Types of Satellites
Image Source: globalmicrowave.org

31. Some Image Processing Software
• ERDAS Imagine
• ENVI
• ILWIS
• ArcGIS
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