Satellite-Based Augmentation Systems
This January/February 2016 issue of Inside GNSS features two articles dealing with satellite-based augmentation systems (SBAS).
The first, "GAGAN — India’s SBAS: Redefining Navigation over the Indian Region," by authors from the Indian Space Research Organization (ISRO) describes the completion of that nations GPS-Aided Geo Augmented Navigation system.
The second is "GNSS Satellite-Based Augmentation Systems: A Potential New Time Keeping System for Future Generations."
The issue also includes an article by another set of ISRO authors, "Measuring Navigation Payload Absolute Delay," describing a new approach to measuring navigation payload absolute delay to improve ranging accuracy to navigation satellites.
Redefining Navigation over the Indian Region
Recognizing the potential benefits of satellite-based augmentation systems, India took the early initiative to create its own SBAS called GAGAN — GPS Aided Geo Augmented Navigation.
A Potential New Time Keeping System for Future Generations
This article describes development and testing of a novel time-keeping system that could provide increased time-synchronization performance for future upgrades of both the onboard and ground segments of SBAS systems.
In Radiation Mode
Satellite navigation signals transmitted on different carrier frequencies are imperfectly synchronized due to different hardware paths corresponding to each signal. An engineering team from the Indian Space Research Organization presents a laboratory method to measure the total navigation payload delay in satellite transmissions.
Rather than highlighting the inadequacies and vulnerabilities of GNSS, the wide-ranging efforts to augment, supplement, and improve on it actually underline the centrality of space-based systems for modern PNT capabilities.
Small GPS jammers, particularly the 'personal privacy devices' readily available on the Internet, pose one of the greatest risks to the nation's critical infrastructure, according to a now public Homeland Security assessment.
Europe's space community rang in the New Year with the European Union (EU) Space Policy conference in Brussels and the European Space Agency (ESA) media briefing in Paris, illustrating not only the disposition of materiel and troops but also their intent and even the level of morale.
Catching thieves, testing Einstein, Russian remodel, and 911 training.