GNSS

US Air Force puts more power into GPS Block IIR-M C/A-code

April 1, 2017By
Figure 2. Plot of L1 C/A-code C/N0 over time for consecutive passes of satellite PRN 05 (SVN 50) tracked by a Leica GR10 receiver located in Kourou, French Guiana, on Feb. 6–8, 2017. The satellite’s unhealthy period on Feb. 7 is indicated by the gray shaded area.

By Peter Steigenberger, André Hauschild, Steffen Thoelert and Richard B. Langley Between Feb. 7, 05:02 UTC and Feb. 8, 12:30 UTC, 2017, all seven operational GPS Block IIR-M satellites were consecutively subject to short periods of unavailability. These official outage periods, when the satellite signals were set unhealthy and deemed unusable, were announced ahead of time through Notice Advisories to... read more

GSA contracts with Eutelsat on next-gen EGNOS payload

March 29, 2017By
Credit and copyright: GSA.

The European Global Navigation Satellite Systems Agency (GSA) has selected Eutelsat Communications for the development, integration and operation of the next-generation EGNOS payload on a future Eutelsat satellite. Eutelsat and GSA have concluded a long-term contract valued at €102 million covering the preparation and service provision phases for the EGNOS GEO-3 payload that will be hosted on the Eutelsat 5... read more

Top-level updates from Munich summit on four GNSS

March 22, 2017By

Here’s a panorama in broad strokes across the range of GNSSs, garnered from top system spokespersons at the Munich Satellite Navigation Summit. It’s been several years since breaking news was aired at this annual late winter/early spring event, but it’s always good for a wide-ranging update, recalibrating levels, so to speak. GPS. With 31 operational satellites (24 is baseline) and... read more

Research: Assessment evaluates GNSS receivers’ tolerance of adjacent band

March 22, 2017By

By Stephen Mackey, Hadi Wassaf, Karen Van Dyke, Christopher Hegarty, Karl Shallberg, John Flake and Terence Johnson. The Adjacent Band Compatibility Assessment evaluated the adjacent radiofrequency band power levels that can be tolerated by GPS and GNSS receivers, to advance the U.S. Department of Transportation’s understanding of the extent to which such power levels impact devices used for transportation safety... read more

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EGNOS satellite messages changing this month

March 15, 2017By
EGNOS-chart

The GEO satellites broadcasting EGNOS messages are going to be changed. On March 20, PRN 123 (now in test) will be introduced in the operational platform, and on March 21, PRN 136 will be moved from the operational platform to the test platform. Users equipped with non-(E)TSO-certified SBAS receivers (such as those used in agriculture, surveying, mapping and maritime, but... read more

This article is tagged with , and posted in GNSS, Latest News

SpaceX wins second US Air Force contract to launch GPS III

March 15, 2017By
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SpaceX has won a second contract from the U.S. Air Force for launch services to deliver a GPS III satellite to its intended orbit. SpaceX was awarded the $96,500,490 firm-fixed-price contract over the United Launch Alliance. ULA — a joint venture of Lockheed Martin Space Systems and Boeing Defense, Space & Security — did not compete for the first GPS III launch contract.... read more

Innovation: Position estimation using non-line-of-sight GPS signals

March 15, 2017By and
FIGURE 9.  Normalized overall correlation with contributions from all satellites, including the satellite mirror-image of PRN 5.

Reflected Blessings.
A technique developed by researchers at the University of Illinois at Urbana-Champaign distinguishes a reflected non-line-of-sight (NLOS) signal of a particular satellite from the LOS signal and characterizes the NLOS signal as coming from a virtual mirror-image satellite in the direction of the signal reflection point. By using information on the position and orientation of the reflector, the NLOS signal can be treated as an additional LOS signal. read more

Turbulence not the culprit for Northern Lights’ effect on GNSS

March 14, 2017By
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Researchers at the University of Bath, U.K., have gained new insights into the mechanisms of the Northern Lights, providing an opportunity to develop better satellite technology that can negate outages caused by the natural phenomenon. Previous research has shown that the natural lights of the Northern Lights — also known as Aurora Borealis — interfere with GNSS signals. Plasma turbulence within the Northern... read more