The GPS-aided MEMS-based inertial navigation system is a topic of current interest by many researches. The performance of such systems relies on not only the quality of the MEMS inertial sensors, or the quality of GPS measurements and the geometry of the satellite constellation, but also implementation of time synchronisation of GPS and INS sensors on the integration platforms. The pseudolite-b...

The ionosphere can affect GPS receivers by degrading the signal strength, in some cases causing loss of carrier lock, and by degrading the accuracy of differential corrections. As we enter the solar maximum years, these effects will become more severe, causing frequent GPS outages in the polar and equatorial regions and over the entire North American landmass when magnetic storms occur. These i...

Recommended by Matthijs Spaan This paper investigates the possibility of augmenting an Unmanned Aerial Vehicle (UAV) navigation system with a passive video camera in order to cope with long-term GPS outages. The paper proposes a vision-based navigation architecture which combines inertial sensors, visual odometry, and registration of the on-board video to a geo-referenced aerial image. The visi...

This paper studies the impact of GPS jamming on GPS carrier-phase time transfer. To study this issue, at NIST, we have installed a commercial GPS jamming detector since 2014 April. During 2014 April – 2015 April, the detector detected more than 100 jamming events, though there had been a few outages of jamming detection. The jamming events usually last for less than 2 min. We find that almost a...

GPS/INS integration can provide high accuracy (centimeter level) navigation under good satellite geometry and atmospheric conditions. However, due to GPS signal blockage and accumulative error attributes of INS, a GPS/INS system cannot continuously maintain such high accuracy navigation during GPS outages, which may frequently happen in terrestrial applications, such as when navigating in fores...

This paper investigates the possibility of augmenting an Unmanned Aerial Vehicle (UAV) navigation system with a passive video camera in order to cope with long-term GPS outages. The paper proposes a vision based navigation architecture which combines inertial sensors, visual odometry and registration of the on-board video to a geo-referenced aerial image. The vision-aided navigation system deve...

N O V E M B E R / D E C E M B E R 2 0 1 4 www.insidegnss.com Efficient power transmission and distribution would benefit from synchronized near–real-time measurements of voltage and current phasors at widely dispersed locations in an electric power grid. Such measurements also could enable effective realtime system monitoring and control, which are considered to be the key to preventing wide-sc...

The National Air Traffic Services (NATS) in London require data on the performance likely to be achieved by the navigation system on board aircraft flying in UK airspace. To that end the performance of three different GPS receiver types (all designed for aviation use) has been examined. This paper details the result of that work. The achieved Mean Time Between Failures (referred to here as “Out...

Precise time synchronization is an essential element for APNT technologies, such as wide area multilateration (WAM) and passive pseudo-ranging. The goal is to provide a time service/source that allows APNT technologies to support a required navigation performance 0.3 (RNP 0.3) and provides the navigation integrity and accuracy for surveillance systems that is required for three-mile aircraft se...