Two new ionospheric models enable more precise GPS positions

Nov. 1, 2004 — NOAA’s National Geodetic Survey today announces the release of two new ionosphere models over the continental United States.
These two highly accurate models (MAGIC and ICON) use the full set of Continuously Operating Reference Stations (CORS) and provide ionospheric information between CORS stations and GPS satellites with a three-day delay. Thanks to these models, users will be able to more precisely compute positions from GPS.

Both MAGIC and ICON are prototype models, part of ongoing research projects but are being made available free to the general public for testing and evaluation purposes.  To access the models go to

Questions or comments about the ICON model can be sent to Dr. Dru Smith at  Questions or comments about the MAGIC model should be directed to Dr. Everett Dutton at