Technical documents, data, and services

• GPS Reference Information
• IGS  - International GPS Service
• Latest GPS Precise Ephemeris Data
• NGS  - Precise Ephemerides
• GPS Time
• The RINEX-2 Format
• EGNOS Performance

• GPS Solutions
• GPS World

• EGNOS
• ESA - European Space Agency
• EUREF - Permanent Network
• Galileo - The European Satellite Navigation System
• GJU - Galileo Joint Undertaking
• GLONASS
• IAG - International Association of Geodesy
• IERS - International Earth Rotation Service
• Interagency GPS Executive Board
• ION - The Institute of Navigation
• NASA - National Aeronautics and Space Administration
• NGS - National Geodetic Survey
• NOAA - National Oceanic and Atmospheric Administration
• UNAVCO - University NAVSTAR Consortium
• U.S. Coast Guard - Navigation Center
• USNO - United States Naval Observatory

• Javad Navigation Systems
• Leica Geosystems
• Thales Navigation
• Topcon Positioning Systems
• Trimble

• Civil GPS Service Interface Committee

• Space Environment Center
• Students for the Exploration and Development of Space
• The Satellite’s Encyclopedia
• United States Space Command, GPS Support Center

• Jet Propulsion Laboratory - JPL