lkd-aerospace
Inside GNSS: Engineering Solutions from the Global Navigation Satellite System Community
GPS Galileo Glonass BeiDou Regional/Augmentation
NovAtel
essp
unicore
Inside Unmanned Systems
Inside Unmanned Systems
Thought Leadership Series
Galileo
Inside GNSS • Spring 2007

PNT Executive Group Gains New Co-Chair, Advisory Board

President Bush’s appointment of retired U.S. Coast Guard Vice Admiral Thomas Barrett as Acting Deputy Secretary of Transportation has brought a new co-chairman to the U.S. Space-Based Positioning, Navigation, and Timing Executive Committee (PNT EXCOM).

Inside GNSS • Spring 2007

Galileo Plods On

Europe’s Galileo program continues to take small steps as it waits to see if it can get through an impasse between the European Commission (EC) and the consortium of companies seeking a concession to complete and operate the Galileo system.

Inside GNSS • March/April 2007

More Perils for Galileo . . . and Other GNSS Dramas

A convergence of developments over the past few months has brought Europe’s Galileo program to the most critical passage of its history — at least, since final approval of the GNSS initiative by the European Space Agency (ESA) and the European Union (EU) in 2003 and 2004, respectively.

Inside GNSS • January/February 2007

Galileo: Coping with Change, China, and Challenges

The 14-year (and counting) history of Europe’s Galileo program has always made for a complex story line.

And it’s not getting any simpler.

Among the latest complications: the transition of responsibilities from the Galileo Joint Undertaking (GJU) to a new GNSS Supervisory Authority (GSA, also referred to as the Galileo Supervisory Authority), further extension of negotiations over a long-term concession contract to operate Galileo, and growing pressure from commercial companies to allow them to sell Galileo technology that they have developed or want to develop.

Inside GNSS • November/December 2006

Compass: And China’s GNSS Makes Four

China has confirmed what many have been expecting for some time: it will construct the world’s fourth GNSS system — joining the systems operated by the United States, Russia, and Europe.

Inside GNSS • October 2006

Progress Amid Criticism: Challenging the Galileo Obstacle Course

As the clock runs out on the Galileo Joint Undertaking (GJU) that has guided the institutional development of the European GNSS program for the past four years, negotiators from the GJU and a consortium seeking to build and operate the system are nearing completion of a “head of terms” agreement.

GNSS Solutions • September 2006

Atomic Clocks on Satellites and Mitigating Multipath

Q: GPS satellites used to carry two cesium and two rubidium atomic standards on board. Subsequently, GPS switched to all rubidium clocks. Galileo plans to use hydrogen masers instead. What are the relative merits of these clocks for use in navigation satellites?

A: It is well recognized that the space-qualified atomic clocks in the GPS satellites are an enabling technology, if not the enabling technology for the system. However, they are also one of the more difficult technologies to acquire.

Inside GNSS • July/August 2006

Industry Sees Galileo Contract Outline in 2006

The consortium negotiating to build and operate Europe’s Galileo system now expects to sign an agreement with the Galileo Joint Undertaking (GJU) by the end of 2006.

GNSS Solutions • July/August 2006

Orbital Precession, Optimal Dual-Frequency Techniques, and Galileo Receivers

Q: Is it true that the GPS satellite geometry repeats every day shifted by 4 minutes?

A: It is true that the GPS satellite orbits were selected to have a period of approximately one half a sidereal day to give them repeatable visibility. (One sidereal day is 23 hours, 56 minutes, and 4 seconds long or 236 seconds shorter than a solar day.) However, because of forces that perturb the orbits, the repeat period actually turns out to be 244 to 245 seconds (not 236 seconds) shorter than 24 hours, on average, and changes for each satellite.

Inside GNSS • July/August 2006

BOC or MBOC?

Europe and the United States are on the verge of a very important decision about their plans to implement a common civil signal waveform at the L1 frequency: Should that waveform be pure binary offset carrier — BOC(1,1) — or a mixture of 90.9 percent BOC(1,1) and 9.09 percent BOC(6,1), a combination called multiplexed BOC (MBOC). The desire for a common civil L1 signal is enshrined in a 2004 agreement on GNSS cooperation between the United States and the European Union (EU).

Signals
Trimble
Trimble
Sensonor
NavtechGPS
Spectracom
Summit
CAST
NovAtel
globe Copyright © Gibbons Media & Research LLC. All rights reserved.
1574 Coburg Road No. 233 • Eugene, Oregon 97401-4802 • United States
Telephone 408-216-7561 • Fax 408-216-7525

Problems viewing this page? Contact our webmaster.