Despite the extraordinary advances in global navigation satellite systems (GNSS), the inherent limitation of the weakness of their space-based signals makes such signals easy to block intentionally or accidentally. This makes GNSS insufficient for reliable anytime, anywhere navigation, particularly in GNSS-challenged environments, such as indoors, deep urban canyons, and GNSS-denied environment...

Global Navigation Satellite Systems (GNSS) are now recognized as cost-effective tools for ionospheric studies by providing the global coverage through worldwide networks of GNSS stations. While GNSS networks continue to expand to improve the observability of the ionosphere, the amount of poor quality GNSS observation data is also increasing and the use of poor-quality GNSS data degrades the acc...

GNSS meteorology is the remote sensing of the atmosphere (particularly troposphere) using Global Navigation Satellite Systems (GNSS) to deliver information about its state. The two currently available navigation satellite systems are the Global Positioning System (GPS) and the GLObal’naya NAvigatsionnaya Sputnikovaya Sistema (GLONASS) maintained by the United States and Russia, respectively. Th...

The emergence of China's Beidou, Europe's Galileo and Russia's GLONASS satellites has multiplied the number of ionospheric piercing points (IPP) offered by GPS alone. This provides great opportunities for deriving precise global ionospheric maps (GIMs) with high resolution to improve positioning accuracy and ionospheric monitoring capabilities. In this paper, the GIM is developed based on multi...

This paper presents the results of augmenting 6DoF Simultaneous Localisation and Mapping (SLAM) with GNSS/INS navigation system. SLAM algorithm is a feature based terrain aided navigation system that has the capability for online map building, and simultaneously utilising the generated map to constrain the errors in the on-board Inertial Navigation System (INS). In this paper, indirect SLAM is ...

Global Navigation Satellite Systems (GNSS) has become increasingly interwoven into the fabric of our infrastructure and economic system. However, as GNSS becomes more important for safety of life and economically critical infrastructure, subversive elements will be increasingly tempted to deny or spoof its signals. The fact that GNSS has vulnerabilities is well known and it is becoming recogniz...

Science-based instruments which use radio signals from Global Navigation Satellite Systems (GNSS) have been successfully deployed on several NASA missions. Applications range from Precise Orbit Determination (POD), limb sounding and formation flying. Remotely sensing the Earth's surface using reflected GNSS signals as a bi-static radar source (GNSS-R) is one of the most challenging applications...