201507 July/August 2015

Can you list all the properties of the carrier-smoothing filter?

Q: Can you list all the properties of the carrier-smoothing filter?

A: Carrier-smoothing filters, also known as Hatch filters, are commonly used to reduce (“smooth”) the noise and multipath errors in pseudorange measurements by exploiting the high-precision relative distance information from carrier phase measurements. However, carrier-smoothing filters operate on more than just noise and multipath, and this article summarizes the response of such filters to all relevant inputs.

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By Inside GNSS

Officials Delay First GNSS Authorization Request; Light-Squared Tries to Leverage Issue

The U.S. stance on satellite navigation has long supported international cooperation and a degree of interoperability. In 2010 the Obama administration even adopted a space policy that said foreign satnav services could be used “to augment and strengthen the resiliency of GPS.”

That was easier in the abstract, however, when the only fully functional GNSS was GPS. Now, with other GNSS services coming online, American officials want to think things through again.

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By Dee Ann Divis

ESA and EC at Odds (Again) over Space Governance

At the European Economic and Social Committee’s Space & Society Conference, from left, Daniel Calleja Crespo, director general of European Commission’s DG Growth; EESC Space and Society Project Coordinator Edgardo Maria Iozia, and Giulio Bartolani di Montauto, European Space Agency’s Brussels office.

Reporting from Brussels last year, we explained that the then–brand new EU GNSS Regulation had effectively put to bed years of wrangling over who does what in Europe’s GNSS programs. But the issue reared its head again in Brussels recently, in a highly charged discussion hosted by the European Economic and Social Committee (EESC).

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By Peter Gutierrez

Valérie Renaudin’s Compass Points

Renaudin’s children, Satine and Kylian (left); Irish dancing keeps Renaudin on her toes (right).


Return to main article: "Valérie Renaudin: Navigating a Life with GNSS"

COMPASS POINTS

Engineering specialties

Geomatics engineering, design of dynamic position estimation algorithms, GNSS and other sensors, including inertial MEMS, UWB Tx, hybridization filters for navigation, low-cost sensor error modeling and calibration, and magnetic field processing.

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By Inside GNSS

More Than We Ever Dreamed Possible

Working Papers explore the technical and scientific themes that underpin GNSS programs and applications. This regular column is coordinated by Prof. Dr.-Ing. Günter Hein, head of Europe’s Galileo Operations and Evolution.

Computational power continues to increase at a rapid pace and unlike other areas of technology, this trend is not expected to slow down in the foreseeable future. Software GNSS receivers fully exploit these developments to steadily increase performance.

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By Inside GNSS

Playing by the Rules of World Trade Law

The availability of several GNSSes promises advanced positioning, navigation, and timing services with higher availability and improved accuracy. According to a European GNSS Agency (GSA) market study, nearly 60 percent of receivers, chipsets, and modules already support at least two GNSS constellations, showing that multi-constellation is becoming a standard feature across all market segments. That development brings up questions of law and regulation that require careful handling by GNSS manufacturers, service providers, and policy makers.

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By Ingo Baumann

Software-Defined GNSS Simulator: A Step Forward

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.

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By Inside GNSS

First Position Fix with IRNSS

Figure 1

The Indian Regional Navigation Satellite System (IRNSS) is an Indian Space Research Organisation (ISRO) initiative to build an independent satellite navigation system that provides precise position, velocity, and time (PVT) to users across the Indian region.

The primary objective of IRNSS is to achieve position accuracy of 20 meters (2σ) for dual-frequency users over India and the primary service area (a region extending to about 1,500 kilometers or 930 miles).

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By Inside GNSS