Ionospheric Impact on GNSS Signals

摘要

Space weather can adversely affect accuracy, reliability and, availability of global navigation satellitesystems (GNSS). To be aware of the space weather impact on navigation signals in the L- band, apermanent monitoring of the ionospheric behavior is required in precise and safety of life applications.Enhanced ionization level of the ionosphere increases also ionospheric range errors. Whereas dualfrequency GNSS measurements enable mitigating first order errors, higher order errors do not cancelout by combining the signals at both frequencies.Space weather events affecting the ionospheric plasma distribution may degrade the navigationinformation or even the electromagnetic signal itself.We discuss several space weather effects in the ionosphere such as strong perturbations in plasmadensity and distribution using ground and space based GNSS measurements..The temporal variation of high latitude TEC data extracted from polar TEC maps-indicate a closecorrelation of TEC fluctuations not only with geomagnetic activity indices but'also with particle fluxdata.