This paper presents the development of an Artificial Neural Network electron density profiler based on electron density profiles collected from radio occultation (RO) measurements from LEO (Low Earth Orbit) satellites to improve the spatial and temporal modeling of ionospheric electron density over Europe. The significance in the accurate determination of the electron density profile lies on th...

During the past decade, researchers have been working to develop methods for the assimilation of Global Positioning System (GPS) radio occultation data into numerical weather prediction (NWP) models. Until recently, two strategies have received the most attention: 1) assimilation of the retrieved bending angle profiles, and 2) assimilation of the retrieved refractivity profiles. The assimilatio...

To reduce the sampling rate in global navigation satellite system (GNSS)-radio occultation receivers, it is essential to establish a suitable estimation of Doppler frequency from the received signal in the satellite onboard receiver. This receiver is usually located on low earth orbit satellite and receives GNSS satellites signal in the occultation situation. The occurred Doppler on the signal ...

ECMWF plans to start assimilating GPS radio occultation measurements with a two dimensional (2D) bending angle operator in 2014. We will describe the new operator, and explain how it has been implemented on the parallel computing system. Issues relating to the computational cost of the operator will be discussed, and a new hybrid approach using a 2D operator in the 4D-Var outer-loop and a 1D op...

Abstract We report on a new method to derive the on‐orbit electron density using Tri Global Navigation Satellite System (GNSS) Radio‐occultation (Tri‐GNSS Radio occultation (TGRS)) differential total content data and compare it Constellation Observing for Meteorology Ionosphere Climate‐2 Ion Velocity Meter (IVM) ion data. found that IVM is about 8%–15% lower than TGRS derived at insertion orbit...

CHAMP (CHAllenging Minisatellite Payload) and GRACE (Gravity Recovery And Climate Experiment) formed a satellite configuration for precise atmospheric sounding during the first activation of the GPS (Global Positioning System) radio occultation experiment aboard GRACE on 28 and 29 July 2004. 338 occultations were recorded aboard both satellites, providing globally distributed vertical profiles ...