Global Navigation Satellite Systems Engineering, Policy, and Design
Ubiquitous location-aware mobile devices, mainly GPS-enabled smartphones, have led to a boom in location-based services (LBS), which have been revolutionizing businesses and lifestyles. Common uses of LBSs include asset tracking, location-based advertising, emergency roadside service, turn-by-turn navigation, and real-time traffic & road information sharing.
By Inside GNSS
It is by now well known that GNSS-based localization in built-up urban environments can be extremely inaccurate. This is a fundamental problem that hardware enhancements cannot solve.
A GNSS receiver estimates 3D location and timing from pseudoranges from four or more satellites, assuming that these pseudoranges correspond to direct line-of-sight (LOS) paths from each satellite. In urban canyons, however, the signal from a satellite to the receiver suffers from multipath propagation and shadowing.
By Inside GNSS
Figures and TablesThe current stage of GLONASS evolution is aimed at meeting future user requirements of which the most important is the improved accuracy of positioning.
During the implementation of the GLONASS Space Segment Modernization Program (2012–2015), the GLONASS team is facing the situation in which it is not feasible to launch new navigation satellites because the existing constellation is comprised of GLONASS-M satellites operating beyond their guaranteed design lifetime. Nine more GLONASS-M satellites are in ground storage.
By Inside GNSS
A GNSS single-antenna system can be compared to a single-pixel camera. Electromagnetic waves traveling 20,000 kilometers from every overhead direction can reach us. Yet once at the antenna, this diverse set of information is collapsed into a single magnitude and phase value, then sent off to the receiver so that value can be extracted.
By Inside GNSS
Return to Working Papers article: "More Than We Ever Dreamed Possible"
By Inside GNSS
Return to Working Papers article: "More Than We Ever Dreamed Possible"
By Inside GNSS
Return to main article: “Software-Defined GNSS Simulator: A Step Forward”
By Inside GNSS
A few studies (by universities and industry) have shown the feasibility of simulation of real-time digital intermediate frequency (IF) signals based on a graphics processor unit (GPU). And a couple of articles have also demonstrated use of a universal software radio peripheral (USRP)–based software-defined radio (SDR) as a simulator (in playback mode) in real test environments.
By Inside GNSS
Return to main Working Papers article: "Double Phase Estimator"
By Inside GNSS
Return to main Working Papers article: "Double Phase Estimator"
By Inside GNSS
Return to main Working Papers article: "Double Phase Estimator"
By Inside GNSS
