1. Satellite
Geodesy
Shahbaz Ali Khidri

2. OUTLINE
• Geodesy and Space-Geodesy
• What is Geodesy ?
• Historical perspective
• Space-based technologies
• Applications
• Selected books on Geodesy
• References

3. GEODESY ?
• One of the oldest profession of the world.
• It comes from the words:
Geo = Earth
Daisia = I divide
• Geo Daisia = Dividing the Earth

4. DEFINITION OF GEODESY
• The classical definition:
Geodesy is the science of measuring, and portraying the
earth’s surface.
[Helmert, 1880].
• The modern definition:
Robert
Helmert
(1843 - 1917)
Geodesy is discipline that deals with the measurement and
representation of the earth, including it’s gravity field, in a
3D time varying space.
(International Association of Geodesy)

5. HISTORICAL PERSPECTIVE
• Eratostethens (276 BC – 194 BC) measured the angle of
sun rays between Alexandria and Syene (Egypt).
• Measured the Earth’s circumference accurately with
15% deviation as compared to the current estimate.

6. SUB-DISCIPLINES OF GEODESY
• Geometrical Geodesy
• Dynamical Geodesy
• Mathematical Geodesy
• Space or Satellite Geodesy
• Marine Geodesy
• Etc.

7. SATELLITE GEODESY
• Geodesy with the help of Satellites.
• It is used to study the climate change, water
resources, natural hazards, disasters, etc.

8. SPACE GEODETIC
TECHNOLOGIES
• Positioning techniques
• Global Navigation Satellite Systems (GNSS)
• Altimetry
• Gravity Missions
• Etc.

9. POSITIONING
TECHNIQUES
• Satellite Laser Ranging
• Lunar Laser Ranging
• Etc.

10. POSITIONING
TECHNIQUES
Satellite Laser Ranging
Lunar Laser Ranging

11. GNSS
• GPS
• GLONASS
• Galileo
• Compass

12. ALTIMETRY
• SeaSAT
• GeoSAT
• TOPEX
• JASON-1
• ENVISAT
• Etc.

13. GRAVITY MISSIONS
• GRACE
• CHAMP
• LAGEOS-1
• Etc.
GRACE
LAGEOS-1
Measurements of small changes in
the Earth’s gravitational field

14. APPLICATIONS
• The Deformation of the Earth from Earthquakes.

15. APPLICATIONS
• Volcano Monitoring.
Studies of hazardous
volcanoes in Mexico, Central
America and the Caribbean

16. APPLICATIONS
• Monitoring of water resources.
Monitoring of water resources
(Everglades, south Florida)

17. APPLICATIONS
• Monitoring of soil moisture.
• Soil moisture is critical for vegetation growth and
survival.

18. APPLICATIONS
• Glacier flow.

19. APPLICATIONS
• Landslides.
Ground movements in Berkley Hill, near San Francisco

20. APPLICATIONS

21. SELECTED BOOKS ON
GEODESY
GEODESY: THE
CONCEPTS
by Peter Vanicek, E.J.
Krakiwsky,
Elsevier Science, 1996 Edition
GEODESY
by Wolfgang Torge, Alter de
Gruyter, Berlin, 2000
INTRODUCTION TO GEODESY:
The History and Concepts of
Modern Geodesy
by James R. Smith - 1997
SATELLITE GEODESY,
FOUNDATIONS,
METHODS, AND
APPLICATIONS,
by Gunter Seeber, Walter de
Gruyter, Berlin, 2003

22. REFERENCES
 http://oceanservice.noaa.gov/education/kits/geodesy/welcome.html
 http://gge.unb.ca/Research/GRL/GeodesyGroup/tutorial/tutorial.htm
 http://www.geod.nrcan.gc.ca/geodesy/index_e.php
 http://en.wikipedia.org/wiki/Geodesy
 http://www.ngs.noaa.gov/PUBS_LIB/Geodesy4Layman/TR80003A.HTM
 http://www.colorado.edu/geography/gcraft/notes/datum/datum.html
 http://www3.sympatico.ca/craymer/geodesy/geodesy.html