System and Business News

The System: FCC Asked to Authorize Potential Interferer

February 1, 2011By

In November, December, and January, a regulatory drama with high potential impact on the GPS signal and domestic U.S. GPS users began unfolding before the Federal Communications Commission (FCC). As this magazine goes to press on January 24, the issue remains far from resolved, although hearings and far-reaching decisions may have transpired by mid-February. A company called LightSquared applied to... read more

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The System: GLONASS Blows Itself off Course

January 1, 2011By

Surplus fuel loaded in error onboard the launch rocket caused loss of three new GLONASS satellites on December 5. The mishap burdened the DM-3 booster rocket with an excess of 1.5 to 2 tons of fuel, causing it to deviate from its course after blast-off and dive into the Pacific Ocean instead of reaching orbit altitude — dashing hopes for an imminent,... read more

This article is tagged with and posted in Aviation & Space, Galileo, GLONASS, GNSS, Government, The System

The System: QZSS Puts L1C on the Air

December 1, 2010By

QZSS Puts L1C on the Air JAVAD Receivers Track the First Truly Interoperable Signal JAVAD GNSS engineers in Moscow have released plots of the C/A, L2C, L5, SAIF, and the new L1C signals broadcast by Japan’s QZSS Michibiki, the first satellite to transmit L1C. The company stated that all of its current GNSS receivers can track QZSS signals with a... read more

This article is tagged with , , and posted in BeiDou/Compass, Galileo, GLONASS, GNSS, The System

The System: Galileo PRS Delivery in Question

November 1, 2010By

Once envisioned to orbit 30 satellites, Galileo’s constellation has over time been reduced to a planned, though still not space-borne, four initial satellites plus 14 operational satellites for a total of 18. The European Space Agency (ESA), under direction of the European Commission (EC), confirmed at the October 19–21 European Navigation Conference (ENC) in Germany that it plans to declare... read more

This article is tagged with and posted in BeiDou/Compass, Galileo, GNSS, The System

The System: GLONASS Forecast Bright and Plentiful

October 1, 2010By

At the Civil GPS Service Interface Committee meeting in Portland, Oregon, on September 20, Sergey Revnivykh, Deputy Director General of Roscosmos’s Central Research Institute of Machine Building, reported on the status and future of GLONASS. He provided a number of details on the present constellation and how it will be augmented in the future, stressing that GLONASS is doing well... read more

This article is tagged with and posted in Galileo, GLONASS, GNSS, GPS Modernization, The System

The System: Michibiki Takes Up Station and Other GNSS Constellation Updates

September 1, 2010By
QZSS-orbits

As this issue goes to press in late August, the first Japan Aerospace Exploration Agency Quasi-Zenith Satellite System (QZSS) space vehicle, nicknamed Michibiki, holds steady for a September 11 launch. QZSS will use multiple satellites in inclined orbits, placed so that one satellite always appears near zenith above Japan, well known for its high-rise cities. The design provides high-accuracy satellite... read more

The System: Three’s the Challenge

August 1, 2010By

A small variance in the L5 signal, which remains well within signal specifications and will not affect pseudorange measurements, may show some impact on triple-frequency combinations of the signal’s carrier phase in high-precision applications. Observations suggest a temperature-dependent line bias in one or more carriers as a likely cause of the observed variation in the tri-carrier combination of L1, L2, and L5. read more

This article is tagged with , and posted in GNSS Opinions, GPS Modernization, The System

The System: An L5 Surprise

August 1, 2010By

Researchers at the German Aerospace Center say they have found a small variance in the L5 signal on IIF-1. The signal variation results in no more than a 5-centimeter error with a predictable periodicity of about six hours. The GPS Wing is studying the issue and expects to resolve it before setting the satellite healthy, in another month or so according to the schedule. read more

This article is tagged with , , , , and posted in Aviation & Space, GNSS Opinions, GPS Modernization, The System