Level 79
1 day < 1 min
LeaderboardGuest · Log in
Cartography, GIS, and Geospatial Technology

GPS, Navigation, and Geodesy

An exploration of satellite positioning systems and the science of measuring the Earth's precise shape and location, from ancient surveying to modern GNSS constellations.

60-Second Review

Express review

A condensed, point-by-point summary of the module, for reviewing right before a test or exam.

  1. How GPS and GNSS Systems Work. Satellites broadcast timed signals; receivers trilaterate position from at least four of them.
  2. Global Satellite Navigation Constellations. Four independent nations operate global GNSS constellations: GPS, GLONASS, Galileo, and BeiDou.
  3. Geodesy and the Shape of the Earth. Geodesy models the Earth as an oblate ellipsoid plus a geoid describing true gravitational sea level.
  4. Triangulation and Historical Surveying Methods. Before satellites, triangulation networks measured angles from known baselines to map vast territories.
  5. GPS Applications in Transportation and Logistics. GPS underlies modern aviation, maritime, road freight, and precision-agriculture navigation systems.
  6. Positioning Accuracy and Signal Interference. Atmospheric delay, multipath, and interference limit GPS accuracy; augmentation systems correct for them.
  7. Indoor and Urban Positioning Challenges. Blocked and reflected satellite signals force indoor and urban positioning to rely on other technologies.
  8. Navigation Before Satellites: Celestial and Dead Reckoning. Before satellites, sailors combined dead reckoning with celestial sightings and accurate chronometers.

This module continues after "Remote Sensing and Satellite Earth Observation" in the syllabus. If you haven't reviewed it yet, it may help set the context.

Key points

Visual module map

1How GPS and GNSS Systems Work
2Geodesy and the Shape of the Earth
3GPS Applications in Transportation and Logistics
4Positioning Accuracy and Signal Interference
5Navigation Before Satellites: Celestial and Dead Reckoning

Alternative visual view: a simplified sequence of some of the module's key points, in their order within the syllabus.

Your module mastery

0% (overall measurement)
Approximate breakdown by skill
Understanding of historiographical debate0%

A rough estimate based on the key points reviewed, not an exact measurement of actual mastery.

Final test

You need to review all key points to unlock the final test.

Optional mini-games

Extra practice, with no penalty, to reinforce the module's content.

Review Flashcards

Review each key point with cards that flip to reveal the summary.

Memory

Match each concept with its definition in as few attempts as possible.

Time Attack

Answer true or false statements before time runs out.

Chronological Order

Put the module's key points back in their original order.

Further reading

Bibliography and cited sources used to create this module.

  • Hofmann-Wellenhof, B., Lichtenegger, H., and Wasle, E. (2008). GNSS – Global Navigation Satellite Systems: GPS, GLONASS, Galileo, and more. Vienna: Springer.
  • Misra, P. and Enge, P. (2011). Global Positioning System: Signals, Measurements, and Performance (2nd ed.). Lincoln, MA: Ganga-Jamuna Press.
  • Torge, W. and Müller, J. (2012). Geodesy (4th ed.). Berlin: De Gruyter.
  • Sobel, D. (1995). Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time. New York: Walker and Company.
  • Edney, M.H. (1997). Mapping an Empire: The Geographical Construction of British India, 1765–1843. Chicago: University of Chicago Press.
  • Parkinson, B.W. and Spilker, J.J., eds. (1996). Global Positioning System: Theory and Applications. Washington, D.C.: American Institute of Aeronautics and Astronautics.