Ionospheric scintillations are rapid temporal fluctuations in both amplitude and phase of trans-ionospheric GNSS signals caused by the scattering of irregularities in the distribution of electrons encountered along the radio propagation path. The occurrence of scintillation has large day-to-day variability. The most severe scintillations are observed near the poles (at auroral latitudes) and near the equator (within ± 20 degrees of geomagnetic equator).By Inside GNSS
Trying to revive a years-dead federal program is usually the kind of hopeless task that even Sisyphus wouldn’t touch.
But determined supporters of eLoran are gaining ground in their effort to resurrect the cancelled radio-navigation network and, propelled by new worries over GPS jamming, they appear poised push the issue through.By Dee Ann Divis
GNSS modernization includes not only the global coverage capabilities of GPS, GLONASS, Galileo, and BeiDou, but also regional GNSS enhancement systems such as Japan’s Quasi-Zenith Satellite System (QZSS), the Indian Regional Navigation Satellite System (IRNSS), and the European Geostationary Navigation Overlay Service (EGNOS).By Inside GNSS