Global Navigation Satellite Systems Engineering, Policy, and Design
GNSS technology plays an important role in an ever expanding range of safety, security, business and policy critical applications.
By Mark Petovello
There was a flurry of filings July 9 just as the window closed for public comment on Ligado Networks’ proposal to repurpose satellite frequencies for a terrestrial network — a plan with the potential to interfere with GPS receivers.
The comments emerged as speculation swirled around a July 3 bid by EchoStar for Ligado spectrum supplier INMARSAT. The bid was rejected and, as of press time, EchoStar will have to wait six months before trying again.
By Dee Ann Divis
With plenty of promise, the third launch of Europe’s Galileo constellation took place four years ago. What followed was not at all what was expected, as problems turned much of the promise into gloom.
By Inside GNSS
The UK seems well and truly on the path to leaving the European Union. The implications for the Galileo program are still unclear, and won’t be known until Brexit negotiations are completed, at the earliest.
By Peter Gutierrez
The advent of the Internet of Things (IoT) has considerably increased the number of services and applications that require positioning information. In this sense, IoT positioning sensors usually obtain and deliver their position to a central node where it is further managed and analyzed by a user or scheduler. Nonetheless, the stringent requirements of low-cost IoT sensors in terms of low power consumption to achieve larger battery lifetime are pushing current technologies to their limits.
By Inside GNSS
Today, it appears that the Cospas-Sarsat MEOSAR system, relying on payloads deployed on GNSS constellations (Galileo, GPS, GLONASS), offers all the conditions to meet the new recommendation of ICAO for ADT-system for Commercial Aviation, with a new generation of in-flight triggered beacons, identical to the current ELT in terms of aircraft integration, but capable of receiving triggers and cancellation events from the avionics, from the crew or from internal sensors, and of detecting and managing their inhibitions to maintain the capability to raise alerts and be localized in any situation.
By Inside GNSS
Integrity for Navigation Land Users (INLU) addresses the difficult task of adapting air-based position integrity solutions to land-based activities such as vehicle and rail travel.
By Inside GNSS
GNSS positioning is premised on the idea that the satellite positions are known, or can be calculated. Errors in the computed satellite position will manifest as ranging errors that degrade the positioning accuracy.
By Mark Petovello
Working Papers explore the technical and scientific themes that underpin GNSS programs and applications. This regular column is coordinated by Em. Univ.-Prof. Dr.-Ing. habil. Dr. h.c. Günter W. Hein.
By Günter W. Hein
1. Last Remaining Peatlands
County Kerry, Ireland
√ Ireland is known for its lush green wetlands and raised bogs, also known as peatlands. But most of these areas have been lost due to drainage associated with peat cutting or conversion to agricultural land, according to Wetland Surveys Ireland (WSI). There’s a big push from Europe to conserve the remaining peatlands
All applications of satellite navigation show a strong growth. They can now rely on four global systems (GPS, GLONASS, Galileo and BeiDou) and additional regional systems, sometimes aiming for future global extension (QZSS, NavIC). All these systems and their applications rely on very limited satellite orbit spectrum. This article is providing background and insights on the growing pressure on this limited resource, giving rise to proposals for “sharing” spectrum. How satellite navigation will survive and find the necessary spectrum resources to grow is reviewed in details in the following paragraphs.
By Ingo Baumann
After spending a career as a GNSS advocate and critic, technical interpreter and PNT raconteur, our colleague, Glen Gibbons, begins his transition to Editor Emeritus status this month. And while his daily GNSS activities cease, his contribution for thoughtful analysis, cogency and a reasoned perspective are retained—his imprimatur, gratefully accepted.
By Inside GNSS
Q: What is navigation message authentication?
A: As of today, all open civil GNSS signals are transmitted in the clear, conforming to interface specifications that are fully available in the public domain. Receivers will accept any input that conforms to the specifications and treat it as if it came from a GNSS satellite. Combined with the extremely low power levels of GNSS signals this makes it almost trivially simple to spoof a GNSS receiver.
By Inside GNSS
