Space Geodetic Measurements of Active Crustal Motions

Spring 2005: Lectures on Tuesdays, 8:30 to 10:20 pm - Labs on Thursdays, 8:30 to 11:20 pm
Contact and information: Prof. Eric Calais, CIVIL 3273,


In the late 90's, space-based geodetic techniques such as the Global Positioning System (GPS) reached a level where millimeter-level positioning became achievable globally. In geophysics, GPS measurements have been widely used over the past decade to monitor crustal displacements, with precision levels on the order of 2-3 mm/yr (horizontally) now routinely achieved.

High precision GPS geodesy and its applications to geophysics will give students a fundamental understanding of error sources and issues relevant to multiple fields, such as surveying, navigation, transportation, GIS, as well as geophysics.

This course will give an overview of the major space geodetic techniques (VLBI, SLR, GPS) and focus on the theory and practice of GPS. A good follow-up course is Kinematics of lithospheric deformation.

The labs will provide hands-on experience in field and data processing techniques, including programming a simple GPS data processing software and learning to use a high-end research software (GAMIT). Knowledge of Matlab and Unix/Linux is not required but will help.

GPS GPS antenna on a tripod during field measurements in Mongolia.



  1. Getting used to Unix/Linux and Matlab
  2. Datums and coordinate systems
  3. Manipulating GPS satellite orbits
  4. From GPS ephemerides to ECEF positions, (1/2)
  5. From GPS ephemerides to ECEF positions, (2/2)
  6. Manipulating GPS data
  7. GPS data quality control
  8. From pseudoranges to position
  9. Processing a 24-hour RINEX observation file (1/2)
  10. Processing a 24-hour RINEX observation file (2/2)
  11. Processing GPS data with GAMIT
  12. Adjustments and reference frame implementation with GLOBK
  13. Surveying with GPS: field measurements

Find data files here.


  1. A recipe for GAMIT.
  2. GAMIT manual, pdf.
  3. GLOBK manual, pdf.
  4. Gamit-Globk homepage at MIT, by S. McClusky.
  5. GPS data processing with GAMIT/GLOBK, a great ressource by M. Murray and M. Battaglia.
  6. GAMIT setup files, from SOPAC at Scripps Institution of Oceanography.

Grading system

Grading will be based on:
  1. Lab and home work, 50% of grade: Assignments will be given at the beginning of each lab. Any part of the assignment not finished during the lab will be done as homework. It must be returned by the end of the week (before Wednesday 8:30 PM).
  2. A term project, 50% of grade: The project must consist of a using and processing GPS data for a high-precision (cm-level or better) application. You may choose a topic related to your graduate research or something new you are interested in learning more about. Each student must have picked his project by the end of the second week of the term. The final product will be:

Suggested reading

Two basic papers: