Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

GIOVE A transmits loud and clear

10.03.2006


After a successful launch on 28 December 2005, GIOVE A began transmitting navigation signals on 12 January 2006. Work is currently being performed to check the quality of these signals.



In space, the success of a mission relies on the achievement of a series of milestones. This is especially true for a pioneering mission such as GIOVE A, the first Galileo satellite, launched late last year under the European Space Agency’s responsibility.

Manufacture, launch, reaching final orbit and transmission of first signals: all these key steps were met by the satellite, which is now going to achieve its first goal, the filing for the frequencies allocated to Galileo by the International Telecommunication Union (ITU).


After launch and platform commissioning, GIOVE A started signal transmission on 12 January and the quality of these signals is now being checked. This checking process is employing several facilities, including the Navigation Laboratory at ESA’s European Space Research and Technology Centre (ESTEC), in the Netherlands, the ESA ground station at Redu, in Belgium, and the Rutherford Appleton Laboratory (RAL) Chilbolton Observatory in the United Kingdom.

Chilbolton’s 25 metre antenna makes it possible to acquire the signals from GIOVE A and verify they conform to the Galileo system’s design specification. Each time the satellite is visible from Chilbolton, the large antenna is activated and tracks the satellite. GIOVE A orbits at an altitude of 23 260 kilometres, making a complete journey around the Earth in 14 hours and 22 minutes.

Every orbital pass provides an opportunity to analyse the signals from the satellite. The quality of the signals transmitted by GIOVE A will have an important influence on the accuracy of the positioning information that will be provided by the user receivers on the ground, so a detailed check-out of the signal properties is mandatory. The signal quality can be affected by the environment of the satellite in its orbit and by the propagation path of the signals travelling from space to ground. Additionally, the satellite signals must not create interference with services operating in adjacent frequency bands, and this is also being checked.

The engineers at Chilbolton have means to observe and record in real time the spectrum of the signals transmitted by GIOVE A. Several measurements are performed relating to transmitted signal power, centre frequency and bandwidth, as well as the format of the navigation messages generated on-board. This allows the analysis of the satellite transmissions in the three frequency bands which are reserved for it and confirmation that GIOVE A is transmitting that which is expected of it.

The GIOVE A mission also represents an opportunity for the testing of a key element of the future Galileo system, the user receivers. The first Galileo experimental receivers, manufactured by Septentrio of Belgium, were installed at the Redu and Chilbolton In Orbit Test Stations and at the Guildford, United Kingdom, premises of Surrey Satellite Technology Limited (SSTL), the manufacturer of the satellite and now in charge of its control in orbit.

A meticulous task, sometimes tedious, but essential for the progress of the project, ensuring that Galileo, the joint civilian navigation initiative from the European Space Agency and the European Commission, can offer the value added services which will fundamentally depend on the quality of the transmitted signals.

Dominique Detain | alfa
Further information:
http://www.esa.int/esaNA/SEM21VMVGJE_index_0.html

More articles from Physics and Astronomy:

nachricht Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science

nachricht NASA's fermi finds possible dark matter ties in andromeda galaxy
22.02.2017 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>