1. The IGS introduction.http://igscb.jpl.nasa.gov/overview/viewindex.html.
2. M. Shaw, GPS Modernization: On the Road to the Future. UN/UAE/US Workshop on GNSS Applications (2011).
3. R. B. Langley et al., The GPS Broadcast Orbits: An Accuracy Analysis,New Trends in Space Geodesy(2000).
4. D. L. M. Warren, J.F. Raquet, Broadcast vs Precise GPS Ephemerides: A Historical Perspective, J. GPS Solutions 7 (2003) 151-156.
5. M. S. B. Starr et al., A Long-Term Statistical Analysis of the Accuracy of GPS and GLONASS Broadcast Orbit and Clock Models, 17th International Technical Meeting of the Satellite Division of the Institute of Navigation(2004) 2095-2103.