galileo constellation

galileo constellation插图

30 satellites
The Galileo constellation comprises of30 satellitesplaced in MEOMedium Earth orbitMedium Earth orbit (MEO), sometimes called intermediate circular orbit (ICO), is the region of space around the Earth above low Earth orbit (altitude of 2,000 kilometres (1,243 mi)) and below geostationary orbit (altitude of 35,786 kilometres (22,236 mi)).en.wikipedia.orgorbit,with 10 satellites placed in each of 3 orbital planes (at 56 nominal inclination) distributed evenly round the equator.Body dimensions:2.5 x 1.2 x 1.1 mNavigation signals:3 bands (E5, E6, E1)Solar generator power:1.9 KwSpan solar generator:14.67 m

What constellations are closest to the constellation Leo?

These are:the Spring Triangle (Arcturus in Botes,Spica in Virgo,and Regulus in Leo)the Diamond of Virgo (Cor Caroli in Canes Venatici,Arcturus in Botes,Spica in Virgo,and Denebola in Leo)the Summer Triangle (Vega in Lyra,Altair in Aquila,and Deneb in Cygnus)More items…

What constellations border the Leo constellation?

Leo is one of 13 zodiac constellation and is located between Cancer and Virgo in Northern Hemisphere’s second quadrant (NQ2). Other neighbouring star constellations include Crater, Lynx and Ursa Major. You can see Leo from latitudes between +90 and -65 degrees. The constellation is one of the largest in the sky.

How many Galileo satellites are now in orbit?

List of Galileo satellites. This is a list of past and present satellites of the Galileo navigation system . As of December 2021, 28 Galileo (4 IOV In Orbit Validation and 24 FOC Full Operational Capability) satellites have been launched. The 2 GIOVE prototype vehicles were retired in 2012, 22 satellites are operational, 1 is not available …

What did Galileo use a telescope for?

The Telescopes of Galileo Galileo’s primary instrument was a rudimentary refracting telescope, which he used to observe the universe. His first version had an 8x magnification, but he quickly improved it to the 20x magnification he used for his observations on Sidereus nuncius.

Why was the Galileo constellation chosen?

The inclination of the orbits was chosen to ensure good coverage of polar latitudes , which are poorly served by the US GPS system.

How many satellites are in Galileo?

Galileo : a constellation of navigation satellites. When Galileo, Europe’s own global satellite navigation system, is fully operational, there will be 24 satellites plus spares in Medium Earth Orbit (MEO) at an altitude of 23 222 kilometres.

Why is the inclination of the orbits chosen?

The inclination of the orbits was chosen to ensure good coverage of polar latitudes, which are poorly served by the US GPS system. From most locations, six to eight satellites will always be visible, allowing positions to be determined very accurately – to within a few centimetres.

How many member states are there in ESA?

Find out more about space activities in our 22 Member States, and understand how ESA works together with their national agencies, institutions and organisations.

How long does it take for a satellite to orbit the Earth?

The satellites will be spread evenly around each plane and will take about 14 hours to orbit the Earth. Two further satellites in each plane will be a spare; on stand-by should any operational satellite fail.

What is the ESA?

About ESA. The European Space Agency (ESA) is Europe’s gateway to space. Its mission is to shape the development of Europe’s space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world. Highlights.

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How does SADM work?

SADM is the drive mechanism that connects the solar arrays to the spacecraft and rotates them slowly so that the surface of the arrays can remain perpendicular to the Sun’s rays at all times .#N#The gyroscopes measure the rotation of the spacecraft.#N#The reaction wheels control the rotation of the spacecraft. When they rotate, so does the spacecraft. It rotates twice per orbit to allow the solar arrays to remain parallel to the Sun’s rays.#N#The magneto bar modifies the speed of rotation of the reaction wheels by introducing a torque (turning force) in the opposite direction.#N#The power conditioning and distribution unit regulates and controls power from the solar arrays and batteries and distributes it to all the spacecraft’s subsystems and payload.#N#The on-board computer controls all aspects of spacecraft and payload functioning.

What is the L band antenna?

The L-band antenna transmits the navigation signals in the 1200-1600 MHz frequency range. #N#The SAR (Search and Rescue) antenna picks up distress signals from beacons on Earth and transmits them to a ground station for forwarding to local rescue services.#N#The C-band antenna receives signals containing mission data from Galileo Uplink Stations. This includes data to synchronise the on-board clocks with a ground-based reference clock and integrity data which contains information about how well each satellite is functioning. The integrity information is incorporated into the navigation signal for transmission to users.#N#Two S-band antennas are part of the telemetry, tracking and command subsystem. They transmit housekeeping data about the payload and spacecraft to ground control and, in turn, receive commands to control the spacecraft and operate the payload. The S-band antennas also receive, process and transmit ranging signals that measure the satellite’s altitude to within a few metres.#N#The infrared Earth sensors and the Sun sensors both help to keep the spacecraft pointing at the Earth. The infrared Earth sensors do this by detecting the contrast between the cold of deep space and the heat of the Earth’s atmosphere. The Sun sensors are visible light detectors which measure angles between their mounting base and incident sunlight.#N#The laser retro-reflector allows the measurement of the satellite’s altitude to within a few centimetres by reflecting a laser beam transmitted by a ground station. The laser retro-reflector is used only about once a year, as altitude measurements via S-band antenna ranging signals are otherwise accurate enough.#N#The space radiators are heat exchangers that radiate waste heat, produced by the units inside the spacecraft, to deep space and thus help to keep the units within their operational temperature range.

What happens if a maser clock fails?

Should the maser clock fail, however, the operating rubidium clock will take over instantaneously and the two reserve clocks will start up. If the problem with the failed maser clock is unique to that clock, the second maser clock will take over from the rubidium clock after a few days when it is fully operational.

How many clocks does Galileo have?

In this way, by having four clocks, the Galileo spacecraft is guaranteed to generate a navigation signal at all times. The clock monitoring and control unit provides the interface between the four clocks and the navigation signal generator unit (NSU).

How many clocks does a spacecraft have?

The spacecraft has four clocks, two of each type. At any time, only one of each type is operating. Under normal conditions, the operating maser clock produces the reference frequency from which the navigation signal is generated.

What is the purpose of two S-band antennas?

Two S-band antennas are part of the telemetry, tracking and command subsystem. They transmit housekeeping data about the payload and spacecraft to ground control and, in turn, receive commands to control the spacecraft and operate the payload.

How accurate is the Rubidium clock?

A rubidium clock will be used should the maser clock fail. It is accurate to within 1.8 ns over 12 hours. Rubidium clock.

How many satellites are in Galileo?

The Galileo constellation comprises of 30 satellites placed in MEO orbit, with 10 satellites placed in each of 3 orbital planes (at 56º nominal inclination ) distributed evenly round the equator. The active constellation comprises of 24 satellites (Walker 24/3/1), including 6 spare satellites, which can be moved to replace any failed satellite …

What happens if a maser clock fails?

Should the maser clock fail, however, the operating rubidium clock will take over instantaneously and the two reserve clocks will start up. If the problem with the failed maser clock is unique to that clock, the second maser clock will take over from the rubidium clock after a few days when it is fully operational.

Why is the altitude of the Galileo satellite chosen?

Galileo Space Segment. The altitude of the satellites has been chosen to avoid gravitational resonances so that, after initial orbit optimisation, station-keeping manoeuvres will not be needed during the lifetime of a satellite. The altitude chosen also ensures a high visibility of the satellites.

What is the C band antenna?

The C-band antenna receives signals containing mission data from Galileo Uplink Stations. This includes data to synchronise the on-board clocks with a ground-based reference clock and integrity data which contains information about how well each satellite is functioning. The integrity information is incorporated into the navigation signal for transmission to users.

How are satellites identical?

All satellites are identical in terms of design, performance capability and fuel load. Each satellite broadcasts navigation timing signals together with navigation data providing the clock and ephemeris correction data which are essential for navigation. The orbit altitude of 23 222 km (orbital radius: 29994 Km) results in an orbit …

What is the VDOP of a constellation?

This constellation provides good local geometries with a typical vertical dilution of precision (VDOP) of 2.3 and horizontal dilution of precision (HDOP) around 1.3. An additional benefit of the constellation geometry is the limited number of planes, which allows for faster deployment and reduced constellation maintenance costs due to the capability to launch multiple satellites with a single launcher.

How far should each satellite be from the orbit plane?

The position constraints for individual satellites are set by the need to maintain a uniform constellation, for which it is specified that each satellite should be within +/- 2° of its nominal position relative to the adjacent satellites in the same orbit plane and should be within 2° of the orbit plane.

What was Galileo’s work?

Galileo’s work laid the foundation for today’s modern space probes and telescopes. Happy Birthday Galileo and thanks for all the celestial gifts! In 1989, Galileo Galilei was memorialized with the launch of a Jupiter-bound space probe bearing his name. During its 14-year voyage, the Galileo space probe and its detachable mini-probe, visited Venus, …

Why did Galileo crash into Jupiter?

In order to avoid the possible contamination of one of Jupiter’s moons, the Galileo space probe was purposely crashed into Jupiter at the end of its mission in September 2003. Page Updated: March 13, 2019.

What planets did the Galileo probe visit?

During its 14-year voyage, the Galileo space probe and its detachable mini-probe, visited Venus, Earth, the asteroid Gaspra, observed the impact of Comet Shoemaker-Levy 9 on Jupiter, Jupiter, Europa, Callisto, IO, and Amalthea. In order to avoid the possible contamination of one of Jupiter’s moons, the Galileo space probe was purposely crashed …

What did Galileo learn from his observations of Venus?

With his observations of the phases of Venus, Galileo was able to figure out that the planet orbits the Sun, not the Earth as was the common belief in his time. Curious about the Sun, Galileo used his telescope to learn more. Not knowing that looking at our very own star would damage his eyesight, Galileo pointed his telescope towards the Sun.

What did Galileo discover about the Moon?

At the time, most scientists believed that the Moon was a smooth sphere, but Galileo discovered that the Moon has mountains, pits, and other features, just like the Earth.

Which object did Galileo turn his gaze toward?

Click here for more information about space probes that have visited and observed Jupiter. Galileo turned his gaze toward Venus, the brightest celestial object in the sky – other than the Sun and the Moon.

When was Donato’s letter written?

Draft of a letter to Leonardo Donato, Doge of Venice, August, 1609, and Notes on the Moons of Jupiter, January 1610. Credit: University of Michigan Special Collections Library

What is the GMS?

The GMS communicates with the Galileo satellites through the network of ULSs. The GMS and GCS interface the satellites with a worldwide network of ground stations implementing monitoring and control functions: Galileo Sensor Stations (GSS), which collect and forward Galileo SIS measurements and data to the GCCs in real time.

What is the Galileo system?

The Galileo system is comprised of numerous components, including the satellites in space, a ground segment across several locations and end users.

What is the ULS in Galileo?

Galileo Uplink Stations (ULS), which distribute and uplink the mission data to the Galileo constellation.

What is the Galileo user segment?

The Galileo user segment is composed by all the compatible receivers and devices which collect the Galileo SIS and compute their location. There are different users´ communities depending on the application and covering a wide range, from transport to timing applications.

What is GCS in space?

The GCS handles spacecraft housekeeping and constellation maintenance by means of the network of TT&Cs stations globally distributed. The scope of this functionality includes control and monitoring of the satellites and payload, planning and automation functions that allow safe and correct operations to take place and the support of payload related operations.

What is GRSP in geodetics?

The Geodetic Reference Service Provider (GRSP): supports the GCC in realising the Geodetic Reference Service Provider (GTRF), consistently with the International Terrestrial Reference Frame (ITRF).

Where is the Galileo ground segment located?

The Galileo ground segment consists of two Galileo Control Centres (GCC) situated in Oberpfaffenhofen (Germany) and Fucino (Italy).

What are the objectives of Galileo?

The Galileo Evolutions are currently under technical study within the European GNSS Evolution Programme (EGEP), an ESA optional programme supported by 17 Member States and Canada. Its primary aim is to undertake research and development in and verification of technologies relating to regional space-based augmentation systems (SBAS) and global navigation satellite systems (GNSS). Regarding Galileo, EGEP objectives are: 1 define future system architectures for Galileo and prepare the technology for future versions of the system; 2 provide testbeds and system tools; 3 improve Agency knowledge of GNSS performance monitoring and the principal environmental factors influencing performance; 4 promote and support scientific exploitation of Galileo.

What is the goal of the EGEP?

Another main objective of the EGEP is the preparation of the future generation of Galileo (Galileo Second Generation, G2G), the progressive introduction of which is foreseen in the first years of the 2020s, when the first launched Galileo satellites will reach the end of their operational life. The G2G activities include studies on the benefits, feasibility and impact of the different concepts on which the analysis will focus (at system level, in the ground segment, payloads and other areas). One of its main objectives is the compilation of all these studies for the elaboration of a possible frame of reference for the Second Generation of Galileo, also incorporating the lessons learned from the first generation.

What is the G2G?

The Galileo Second Generation (G2G) is expected to deliver improved performance and RNP (Required Navigation Performances) features such as reliability, maintainability, availability, continuity, accuracy and integrity. This is why the European Commission (EC) has decided to launch a Transition Programme with ESA for technical definition and implementation.

What is the IOC phase?

The IOC stage represents the partial commissioning of the ground and space infrastructure as from 2014-2015 and the provision of the Open Service, the Search And Rescue service and the PRS . The provision of these Galileo Initial Services was declared in December 2016. The procurement of the IOC phase included the first batch of satellites (14 additional satellites to the 4 IOV satellites), the launch services, the needed mission and control ground infrastructure, the system support services and the corresponding operations. Details on the different steps of this phase are presented in Galileo Deployment

How many phases are there in Galileo?

The Galileo program has been structured according to three main phases: In-Orbit Validation (IOV) phase: The IOV phase consisted of qualifying the system through tests and the operation of two experimental satellites and a reduced constellation of four operational satellites and their related ground infrastructure.

What is phase 1 Galileo?

Phase 1 (HA Initial Service) from 2022. Provision of an initial Galileo High Accuracy Service resulting from the implementation of a high-accuracy data generation system processing Galileo system data only. The HA initial service will deliver Service Level 1 only with a reduced performance (below the full service’s targets).

What is the Galileo program?

The Galileo program is Europe’s initiative for a state-of-the-art global satellite navigation system, providing a highly accurate, guaranteed global positioning service under civilian control. While providing autonomous navigation and positioning services, the system established under the Galileo program is at the same time interoperable …

What Is the Status of the Galileo GNSS in 2021?

In May 2002, the European Community and the European Space Agency formed the Galileo Joint Undertaking (GJU) to oversee the Galileo global satellite positioning program’s development. In July 2004, the European GNSS regulatory body, GSA, was created by the European Council first as a community agency and assigned the job of reviewing existing satellite positioning and navigation programs, including the European Geostationary Navigation Overlay Service (EGNOS) and Galileo.

How many satellites did Galileo have?

Fifteen years and many reorganizations later, on February 11, 2019, about seven months after the last four satellites were launched, Galileo entered full service with an ultra-modern, 22-satellite constellation.

What is Galileo’s business model?

Galileo is designed with a tiered business model to better support traditional positioning and navigation applications and foster innovation. Additionally, Galileo signals — L1, E5A and E5B — are compatible with the existing L1 GPS signal and the new L5 signal.

How does Galileo help with navigation?

Since Galileo works with GPS, navigation is improved as there are always satellites “in view,” providing more accurate and reliable positioning for the receiving device, particularly for dual-frequency service. Even though it just started full commercial service, Galileo accounts for most of the satellites broadcasting in the E1/E5a frequency band, providing a significant contribution to the dual-frequency (high-precision) service landscape. This contribution is also particularly important for navigation in cities, where satellite signals can often be blocked or echoed (multipath) by buildings. With satellites’ time references based on rubidium and passive hydrogen masers, Galileo delivers better timing with 30-nanosecond accuracy, enabling more resilient synchronization for time-critical events, including aviation, telecommunications, financial transactions and power distribution networks.

What is the Galileo system?

It is a highly accurate , civilian-controlled, state-of-the-art positioning system that works with GPS in the U.S. and GLONASS in Russia. As it provides dual-frequency as standard, Galileo offers real-time positioning with precision down to the meter, which other public positioning systems haven’t accomplished. This satellite system enables users to know their exact position and provides significant benefits to everyday products and services that leverage navigation, from cellular phones to vehicles.

How many Galileo satellites are in orbit?

With 26 satellites in orbit (including reserves) and over 1.5 billion devices worldwide enjoying the benefits of high-precision navigation, Galileo is already slated for upgrades with a new generation of satellites and terrestrial infrastructure to ensure quality service for decades to come. Following the decision to accelerate the development of “Galileo Next Generation,” ESA asked European manufacturers in 2020 to start submitting bids for the first set of the second generation (G2) Galileo satellites. They are expected to be placed in orbit around 2024. The next generation is being specified to be ultra-flexible with more software-defined and fewer dedicated hardware features.

What is Galileo geo positioning?

Galileo-based geo-positioning has all the ingredients to change the game for multiple industries and application segments. Across the spectrum of business and engineering, developers and designers must step back to understand the profundity of these enhancements Galileo has brought when planning product roadmaps and considering innovation. Telit is among the first receiver module vendors to embrace the Galileo revolution and deliver a new generation receiver. Telit’s SE868SY-D module provides high precision and superior urban canyon performance with a refresh rate of up to 25 Hz, making it ideal for flying platforms such as UAVs.

What is IPS in a GNSS?

The IPS monitors and forecasts solar and ionospheric activity and predicts its effect on GNSS signals and on the final performance of user applications. The Service makes it possible to anticipate any degradation of performance, allowing operators to put in place mitigation measures in good time. Read more…

What is OSNMA in GNSS?

This is the first-ever transmission of authentication features in open GNSS signals of a global navigation system. OSNMA test signals are being broadcast by the Galileo constellation. The Galileo OSNMA is an authentication mechanism that allows GNSS receivers to verify the authenticity of GNSS information, making sure that …

What is the EGNOS service?

Its name is EGNOS, the European Geostationary Navigation Overlay Service. Transmitting signals from a duo of satellite transponders in geostationary orbit, EGNOS gives additional precision to US GPS signals – delivering an average precision of 1.5 metres over European territory, a tenfold improvement over un-augmented signals in the worst-case – and also confirmation of their ‘integrity’ – or reliability – through additional messaging identifying any residual errors. Read more…

How many satellites are in orbit in Europe?

Ten years of safer skies with Europe’s other satnav system. With 26 satellites in orbit and more than two billion receivers in use, Europe’s Galileo satellite navigation system has made a massive impact.

What is GSOp in Galileo?

On 25 February, the Galileo Service Operator (GSOp) received from the EUSST a collision risk alert between GSAT0219 and an inert Ariane 4 upper stage launched in 1989. Following this warning, GSOp started to closely monitor the risk, in close cooperation with EUSST that was refining its predictions. Read more….

What is PPP correction?

Precise Point Positioning (PPP) correction services have been in the market for a long time to either assist vessels maneuver at ports or for measuring instruments for construction and geodesy. Today, highly precise positioning goes beyond industrial use cases and is available to mass market applications and devices. Read more…

What is EUSPA?

EUSPA, the European Union Agency for the Space Programme: The start of a new era for EU Space. The European Union Agency for the Space Programme, EUSPA, was launched on 12 May marking the start of a new era for EU Space.