Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

GIOVE-A laser ranging campaign successful

04.10.2006
Fourteen laser ranging stations participated in a campaign to track ESA’s GIOVE-A satellite during the spring and summer of 2006, providing invaluable data for the characterisation of the satellite’s on-board clock. The campaign was coordinated by the International Laser Ranging Service (ILRS) and the GIOVE Processing Centre at ESA-ESTEC.

GIOVE-A, developed by Surrey Satellite Technology Ltd (UK), was launched from Baikonur Cosmodrome on 28 December 2005 and placed into a medium Earth orbit with an altitude of 23 260 km. Carrying a payload consisting of rubidium clocks, signal generation units and a phase array of individual L-band antenna elements, GIOVE-A started broadcasting Galileo signals on 12 January, securing the frequencies allocated by the International Telecommunications Union for the Galileo system.

The performance characterisation of the on-board clocks is significantly enhanced by the use of Satellite Laser Ranging (SLR), a high precision technique for orbit determination that is independent of the navigation signal generation. The technique is based on a global network of stations that measure the round flight time of ultra short laser pulses to satellites equipped with Laser Retro Reflectors (LRR). Laser ranging provides instantaneous range measurements of millimetre-level precision which can be used to derive accurate orbit data.

GIOVE-A is equipped with a LRR having 76 corner cubes, manufactured by IPIE of Russia, which provides a return energy 40% higher than GPS reflectors. The use of SLR data allows a more robust orbit determination, and thus a more accurate clock characterisation. In addition, certain satellite properties relevant to navigation, such as the offset between the centre of mass and the centre of the navigational phase centre, can be verified and calibrated.

The International Laser Ranging Service (ILRS) has agreed to support the GIOVE-A mission by providing SLR data during several tracking campaigns coordinated with the GIOVE Processing Centre at ESA-ESTEC.

The first of these tracking campaigns took place between 22 May and 24 July 2006, with the participation of 14 SLR stations, distributed globally. In addition to confirming the good health of the LRR on GIOVE-A after launch, the SLR data has been essential for a health check and a preliminary performance characterisation of the on-board rubidium clocks.

With GIOVE-A, ESA is validating the critical new technologies needed for the Galileo system and preparing for the next phase of In-Orbit Validation (IOV). For this next step, four satellites will be launched. On completion of IOV, the four satellites will become the initial components of the operational Galileo constellation.

Galileo is a joint initiative of the European Commission and the European Space Agency. It is the first satellite positioning and navigation system specifically designed for civilian purposes and will offer state-of-the-art services with outstanding performance and guaranteed accuracy, integrity, continuity and availability.

Dominique Detain | alfa
Further information:
http://www.esa.int/esaNA/SEM8QOKKKSE_index_0.html

More articles from Physics and Astronomy:

nachricht Artificial agent designs quantum experiments
19.01.2018 | Universität Innsbruck

nachricht Only an atom thick: Physicists succeed in measuring mechanical properties of 2D monolayer materials
17.01.2018 | Universität des Saarlandes

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: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

More genes are active in high-performance maize

19.01.2018 | Life Sciences

How plants see light

19.01.2018 | Life Sciences

Artificial agent designs quantum experiments

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>