Global Navigation Satellite Systems Engineering, Policy, and Design
The nation’s leading GPS experts voted unanimously Monday to oppose allowing Ligado Networks to use spectrum neighboring the GPS band for terrestrial communications.
By Dee Ann Divis
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
Recent presentations and publications have suggested that multi-frequency spoofing is infeasible using low-cost, off-the-shelf equipment, and that a good defense against any but well-funded and technically competent adversaries would be to use a multi-frequency capable survey grade receiver. The authors of this article wish to demonstrate that this is definitively false.
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
Authors: Frank van Diggelen and Mohammed Khider
Google has publicly released GNSS Analysis Tools to process and analyze GNSS raw measurements from your phone. These tools enable manufacturers to see in detail how well the GNSS receivers are working in each particular phone design and thus improve the GNSS design and performance in their phones. Also, with the tools publicly available there is significant value for app-developers, researchers and educators. Here, the authors show what these tools do, and how they reveal details of receiver and signal behavior that are not possible to observe without raw measurements.
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
Michael Ritter is president of Hexagon Positioning Intelligence and also serves as president and CEO of NovAtel Inc. “One of the businesses we are in is making high-end, very-high-signal-quality, very-low-group-delay GNSS receivers,” Ritter told us.
By Inside GNSS
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
The Air Force is scouring the landscape for its next round of receiver technology now that the first increment of its military receiver development program is moving into a deeper testing phase.
By Dee Ann Divis
In the past two decades, satellite navigation systems have undergone great development. The development of new generations of global navigation satellite systems (GNSS), represented by GPS III, Galileo, and the BeiDou global system (BDS), is rapidly advancing.
By Inside GNSS
Multipath is a major phenomenon that degrades the integrity of GNSS-based navigation services. Under multipath, a receiver Delay-Lock Loop (DLL) does not correctly estimate the actual peak of the correlation curve, resulting in ranging errors. To overcome this effect, mitigation techniques have been developed, a detailed discussion of which
By Inside GNSS
