An Ionosonde is a special type of Doppler radar used for the probing bottom side of Ionosphere. Ionosonde system has potential applications in both radio communication and space physics. Modern Ionosonde with improved signal processing techniques made it possible to study the dynamic nature of the Ionosphere in addition to the electron density profile given by the traditional Ionosonde systems....

Double layers (i.e., electric fields parallel to B) form along auroral field lines in the Earth's magnetosphere. They form in order to maintain current continuity in the ionosphere in the presence of a magnetospheric electric field E with V • E 4: 0. Features which govern the formation of the double layers are: (1) the divergence of E, (2) the conductivity of the ionosphere, and (3) the current...

One of the parameters driving the performance of the Wide Area Augmentation System (WAAS) is the Grid Ionospheric Vertical Error (GIVE). The GIVE bounds the estimation error of the ionospheric delay at each Ionospheric Grid Point (IGP). The GIVE is generated such that a user interpolating both the vertical ionospheric delays at the IGP and the GIVE, is protected. The GIVE is a function of sever...

If the upper atmosphere and ionosphere of Triton are controlled by precipitation of electrons from Neptune's magnetosphere as previously proposed, Triton could have the only ionosphere in the solar system not controlled by solar radiation. However, a new model of Triton's atmosphere, in which only solar radiation is present, predicts a large column of carbon atoms. With an assumed, but reason...

We propose a mechanism to explain suggested links between seismic activity and ionospheric changes detected overhead. Specifically, we explain changes in the natural extremely low frequency (ELF) radio noise recently observed aboard the DEMETER satellite at night, before major earthquakes. Our mechanism utilises increased electrical conductivity of surface layer air before a major earthquake, w...

Pioneer Venus orbiter dual-frequency radio occultation measurements have produced many electron density profiles of the nightside ionosphere of Venus. Thirty-six of these profiles, measured at solar zenith angles (chi) from 90.60 degrees to 163.5 degrees , are discussed here. In the "deep" nightside ionosphere (chi > 110 degrees ), the structure and magnitude of the ionization peak are highly v...

The ionospheric plasma is continually perturbed by ultra-low frequency (ULF; 1–100 mHz) plasma waves that are incident from the magnetosphere. In this paper we present a combined experimental and modeling study of the variation in radio frequency of signals propagating in the ionosphere due to the interaction of ULF wave energy with the ionospheric plasma. Modeling the interaction shows that th...

Space weather, primarily the ionosphere, produces the largest GNSS errors. This paper reviews the ionosphere’s effect on satellite ranging measurements and discusses how the effect is accounted for in receivers. In addition, the variations in the ionospheric delay will be discussed along with historical ionosphere delay data on normal days as well as some of the solar storm days with the highes...

To prove a direct relationship between the quasi-static electric field disturbances and seismic activity is a difficult, but actual task of the modern ionosphere physics. This paper presents new results on the processing and analysis of the quasi-static electric field in the upper ionosphere (h=800–900 km) observed from the satellite INTERCOSMOS-BULGARIA-1300 over earthquakes’ source regions (s...

One of the adverse impacts of scintillation on GNSS signals is the loss of lock status, which can lead to GNSS geometry and visibility reductions that compromise the accuracy and integrity of navigation performance. In this paper the loss of lock based on ionosphere scintillation in this solar maximum phase has been well investigated with respect to both temporal and spatial behaviors, based on...