The System

The System: Leap-Second Confusion

March 1, 2015By

The United States Civil GPS Service Interface Committee (CGSIC) has issued a notice about a problem some receivers are having implementing the correct time. The U.S. Coast Guard Navigation Center has received reports of synchronization issues since the implementation of a leap second on Jan. 21. Users experiencing this problem should contact the receiver manufacturer for a firmware or software... read more

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The System: ESA’s Second FOC Moves Up

February 1, 2015By
The fifth Galileo satellite is now pointing toward Earth.

By Tim Reynolds, GPS World European correspondent Director General Jean-Jacques Dordain of the European Space Agency (ESA) announced Jan. 16 that the second errant full-operational capability (FOC) satellite, launched in August, had started its orbital change maneuver the previous day. He anticipated that the orbital change would be completed and the final orbit — “albeit somewhat lower in height than the one... read more

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The System: First Galileo FOC Satellite on the Air

January 1, 2015By

Will Be Employable for Surveying, Precise Positioning, and Geodesy By Peter Steigenberger and André Hauschild, German Aerospace Center (DLR) / German Space Operations Center The first Full Operational Capability (FOC) Galileo satellite started transmitting L-band navigation signals on November 29, 2014. Based on data collected by a global network of GNSS tracking stations of the Cooperative Network for GNSS Observation (CONGO) and... read more

The System: eLoran Operational on Eastern UK Coast

December 1, 2014By
Bridge of the Galatea, a GLA vessel that carries a eLoran receiver and conducted tests of the new system.

Back-up to Vulnerable GPS Signals Required for Busy Shipping Lanes The General Lighthouse Authorities (GLAs) of the UK and Ireland announced October 31 the initial operational capability of UK maritime eLoran. Seven differential reference stations now provide additional position, navigation, and timing (PNT) information via low-frequency pulses to ships fitted with eLoran receivers. The service will help ensure they can... read more

The System: Fregat Design Ambiguity Steered Galileo Wrong

November 1, 2014By

Cross-Installed Hydrazine, Helium Lines Froze Thrusters The root cause of the anomaly that sent two Galileo satellites into the wrong orbit on August 22 was a shortcoming in the system thermal analysis performed during stage design, and not an operator error during stage assembly, according to findings by an independent inquiry board. The independent inquiry board was created by Arianespace,... read more

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The System: One Step Back, Three Steps Forward

September 1, 2014By
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Galileo IOV Bird Mute; New Draft ICD; CS Proved; Late August Launch Orbiting in silence since an onboard power mishap on May 27, troubled E20 emitted cheeps from space on August 6, 7,  and 8, broadcasting on the L1 frequency. Nothing has been heard since.  Meanwhile, the European Commission (EC) published a new draft version of the Galileo Open Service... read more

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The System: GPS III, Always a New Horizon

July 30, 2014By

First, Lockheed Martin began investigating options for its GPS III payload supply line last year.  Then in June of this year, the U.S. Air Force opened a “sources sought”  initiative for a production-ready GPS space vehicle, equipped with an alternate payload, for consideration alongside the Lockheed Martin-built GPS III vehicle. Grumman and Boeing have responded to the U.S. Air Force... read more

The System: GLONASS in April, What Went Wrong

June 24, 2014By
Figure 1. Affected broadcast messages for each GLONASS satellite. Colors indicate the different orbit planes.

By Gerhard Beutler, Rolf Dach, Urs Hugentobler, Oliver Montenbruck, Georg Weber, and Elmar Brockmann What Happened: On April 1, 2014, at 21:15 UTC, all GLONASS satellites started to transmit wrong Broadcast Messages (BM) as previously reported by GPS World. The satellite positions derived from these BM were wrong by up to ± 200 kilometers in each of the three coordinates... read more