The use of space-time processing methods in GNSS interference mitigation is of great interest due to their effectiveness in both narrowband and wideband interference suppression. Techniques to reduce the distortion and bias on the cross correlation function due to space-time filtering are also very important especially for high precision GNSS applications. In this paper, different types of spac...

propagation of radio waves through the troposphere is based on minimum travel time between transmitter and receiver. the troposphere layer affects the propagation of gnss signals and causes errors in point positioning due to (1) delay of the signal, and (2) change of the curvature of the signal path. for this reason gnss users apply models for tropospheric error corrections. one of the commonly...

Benefits from the modernized US Global Positioning System (GPS), the revitalized Russian GLObal NAvigation Satellite System (GLONASS), and the newly-developed Chinese BeiDou Navigation Satellite System (BDS) and European Galileo, multi-constellation Global Navigation Satellite System (GNSS) has emerged as a powerful tool not only in positioning, navigation, and timing (PNT), but also in remote ...

Positioning, navigation, and timing (PNT) is a strategic key technology widely used in military and civilian applications. Global navigation satellite systems (GNSS) are the most important PNT techniques. However, the vulnerability of GNSS threatens PNT service quality, and integrations with other information are necessary. A chip scale atomic clock (CSAC) provides high-precision frequency and ...

Within the Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) there is a need for an assessment of the uncertainty in the integrated water vapour (IWV) in the atmosphere estimated from ground-based global navigation satellite system (GNSS) observations. All relevant error sources in GNSS-derived IWV are therefore essential to be investigated. We present two approaches, a...

In contrast with ground applications the GNSS constellations are not optimized for space applications. Moreover, the different types of mission, i.e. Low Earth Orbit (LEO), Medium Earth Orbit (MEO), Geosynchronous Earth Orbit (GEO), have all specific requirements. Our motivation is to define an «Ubiquitous GNSS receiver (UGNSS)», i.e. a single receiver able to cope with all types of mission. Th...

Ionospheric scintillation occurs mainly at high and low latitude regions of the Earth and may impose serious degradation on GNSS (Global Navigation Satellite System) functionality. The Brazilian territory sits on one of the most affected areas of the globe, where the ionosphere behaves very unpredictably, with strong scintillation frequently occurring in the local postsunset hours. The correlat...

Standalone Global Navigation Satellite System (GNSS) is inadequate for precise navigation of aircrafts. Ground-based Augmentation System (GBAS) augments the performance of GNSS for civil aviation by providing differential corrections to the position of an aircraft during takeoff and landing. Ionospheric gradients affect the accuracy of GNSS and they can be detected and characterized from GNSS o...

J A N U A R Y / F E B R U A R Y 2 0 1 4 www.insidegnss.com 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). GNSS syst...

Original scientific paper A GNSS network of 36 points was established in 2006 in the eastern part of the North Anatolian Fault Zone, which is located between Tokat and Erzincan. GNSS measurements were made in 2006 ÷ 2008 in the Kelkit valley and these points’ velocities were calculated. This study compares GNSS velocities estimated with different datum definitions and the effects on fault locki...