Retrieval of electron density profiles from GRACE radio occultation data

Abstract

As numerous GPS measurements onboard LEO satellites as Microlab-1, CHAMP and COSMIC have shown, the GPS radio occultation technique is a rather simple and inexpensive tool for profiling the electron density of the entire ionosphere from satellite orbit heights down to the E-layer heights. After operationally retrieving more than 200000 electron density profiles from GPS measurements onboard CHAMP in recent years we now report preliminary results from ionospheric radio occultation (IRO) measurements onboard the GRACE satellite. The achieved accuracy of the retrieved electron density profiles is estimated by comparison with independent data obtained from equivalent measurements onboard CHAMP and COSMIC. Combining the electron density retrievals of various satellites, there is a big potential for developing and improving global ionospheric models and for providing reliable space weather information.