 Galileo
|
Galileo, the European Programme for Global Navigation System is a joint initiative of the EC and the ESA. Galileo is the first satellite positioning and navigation system specifically designed for civil purposes. It will offer state of the art services with outstanding performance in accuracy, continuity and availability. It will be more advanced, more efficient and more reliable than the current US GPS monopoly.
Below you will find more information on Galileo and our involvement. Click on the links below if you wish to go straight to a later section:
Galileo
The Galileo system comprises a global constellation of 30 satellites in Medium Earth Orbit (MEO), three planes inclined at 56 degrees to the equator at about 23, 222 km altitude. They are supported by a worldwide network of ground stations.
 There are many applications for Galileo:
Transport
Energy
Finance, Banking and Insurance
Agriculture and Fisheries
Personal Navigation
Emergency and Crisis Management
Environmental Management
Surveying
Recreation
The Galileo System will be managed and operated in the forma of a concession as part of a public-private partnership (PPP). The cost of deploying the system is some 3.4 billion Euros.
Galileo Programme
The Galileo programme is being implemented in three phases:
1st – The definition phase was completed in 2003 providing the basic specifications for the system.
2nd – The deployment and in-orbit validation phase, which is currently underway and aims to perform an in-orbit validation of the system.
3rd – The deployment phase which will commence with the launch of the final satellites to complete the constellation.
Galileo System Test Bed
For the development of the Galileo system, ESA launched the development of the experimental ground segment (Galileo System Test Bed Version 1, GSTB V1) to verify Galileo concepts for orbit determination, time synchronisation and integrity algorithms.
 Following on from this the GSTB V2 project consists of the development and launch of two experimental satellites, the first of which is GSTB V2/A launched on 28 December 2005 on a Soyuz rocket from Baikonur cosmodrome in Kazakhstan. This satellite has been named GIOVE A (Galileo In-Orbit Validation Element), and was launched into a Galileo orbit of 23, 222 km altitude with the main aim of fulfilling the requirements of the International Telecommunications Union (ITU) in respect of the use of the frequencies reserved for Galileo.
The GIOVE A satellite has been developed by Surrey Satellite Technology Ltd (SSTL). It is intended to fulfil the following main objectives:
- Securing frequency filings
- Validation of key technologies such as the rubidium clocks
- Experimenting with the reception of GPS signals from MEO
- Characterisation of the MEO environment using two different radiation monitoring instruments
- Signal experimentation using two transmission channels in parallel.
Chilbolton Observatory’s Role
 Following the GIOVE A satellite launch and a spacecraft commissioning phase, the satellite navigation payload was activated, and the first signals from the spacecraft were detected on Thursday 12th January 2006 using a purpose-built L-band receiver on the 25 metre Chilbolton antenna. This receiver has been designed and built by RAL engineers, and operates over the frequency band 1100 – 1700 MHz.
In order to meet the frequency filing criteria for the ITU, extensive calibration procedures and tracking tests have been performed in the weeks leading up to launch. These procedures have made use of signals from existing satellites including Artemis and GPS, together with precise measurements of emissions from the celestial radio source, Cassiopeia A.
Once the satellite was operational measurements were performed during suitable satellite overpasses, using a spectrum analyser under full computer control, with results recorded automatically, and verifiable in near-real-time using a quick look display system developed by Chilbolton staff. Examples of measurements made include:
- Equivalent Isotropic Radiated Power (EIRP)
- Power spectrum density
- Carrier-to-noise ratio (C/No)
- Occupied bandwidth
- Out of band emissions
This phase of the project lasted until the end of February, during which time many overpasses, each lasting ~7 hours, were tracked and recorded by Chilbolton and SSTL staff.
Rutherford Appleton Laboratory’s Role
Rutherford Appleton Laboratory (RAL) in Oxfordshire is part of STFC along with Chilbolton Observatory. Most of the 240 staff of the Space Science and Technology Department are based at RAL, with only seven staff based full time at Chilbolton. At RAL the 12 metre antennna of the RAL Ground Station was used to communicate with the GIOVE A satellite, sending commands to control the satellite and receive telemetry data. The RAL Ground Station commenced operations as soon as the satellite was launched.
For media enquires regarding STFC Chilbolton Observatory's role or STFC Rutherford Appleton Laboratory's role in Galileo please contact Natalie Bealing in STFC's communications department.
For more information regarding Chilbolton Observatory's involvement with Galileo please contact Darcy Ladd.
More information on the Galileo System can be found on the ESA Galileo website.
|
