astronomy

Meteosat

Meteosat is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Meteosat rather than just read about it. In short: The Meteosat series of satellites are geostationary meteorological satellites operated by EUMETSAT under the Meteosat Transition Programme (MTP) and the Meteosat Second Generation (MSG) program. The MTP program was established to ensure the operational continuity between the end of the successful Meteosat Operational Programme in 1995 and Meteosat Second Generation (MSG), which came into operation at the start of 20…

Key takeaways

Meteosat belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Meteosat to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Meteosat from memory before moving on to harder problems.

Reference excerpt

The Meteosat series of satellites are geostationary meteorological satellites operated by EUMETSAT under the Meteosat Transition Programme (MTP) and the Meteosat Second Generation (MSG) program. The MTP program was established to ensure the operational continuity between the end of the successful Meteosat Operational Programme in 1995 and Meteosat Second Generation (MSG), which came into operation at the start of 2004 using improved satellites. The MSG program provided the prime operational services from 2003 until the MTG (Meteosat Third Generation) program began to gradually replace them. The first MTG operational imager satellite, MTG-I1, launched in December 2022 and became operational in 2025, assuming the prime satellite role for the 0-degree longitude Full Disk scanning service (FDSS) mission. This was joined by the first operational sounder satellite, MTG-S1 when it launched in July 2025, with a second imager satellite, MTG-I2, planned for launch in the second half of 2026.

First Generation

The first generation of Meteosat satellites, Meteosat-1 to Meteosat-7, provided continuous and reliable meteorological observations from space to a large user community. All Meteosat satellites from Meteosat-1 to Meteosat-7 have now been retired. When operational, the Meteosat First Generation provided images every half-hour in three spectral channels (Visible, Infrared) and Water Vapour, via the Meteosat Visible and Infrared Imager (MVIRI) instrument. Until 1 February 2017, Meteosat-7 provided the primary imagery coverage over the Indian Ocean and provided a service relaying data from Argos Data Collection Platforms (DCP), such as buoys, in support of the Tsunami Warning System for the Indian Ocean. A range of processed meteorological products were also produced. The last disseminated Meteosat-7 image was on 31 March 2017. Moving Meteosat-7 to its ultimate resting place in a graveyard orbit commenced on 3 April 2017 and the spacecraft final command sent on 11 April 2017. The satellites were manufactured by a consortium COSMOS, with Aérospatiale in its Cannes Mandelieu Space Centre, as Prime, and included Matra, MBB, Selenia Spazio, Marconi Company. They are 2.1 metres in diameter and 3.195 metres long. Its initial mass in orbit is 282 kg, and in orbit, the satellite spins at 100 rpm around its main axis.

Second Generation ("MSG")

Meteosat Second Generation was designed in response to user requirements to serve the needs of nowcasting applications and numerical weather prediction. In addition, the GERB instrument provides important data for climate monitoring and research. The MSG satellites are 3.2 m in diameter and 2.4 m high and spin anti-clockwise at 100 rpm at an altitude of 36,000 km. The contract for the second generation was awarded to Aérospatiale in its Cannes Mandelieu Space Centre (now Thales Alenia Space), with main subcontractors as Matra, Messerschmitt, Alenia. The satellites are spin-stabilised like the previous generation, but with many design improvements. The more frequent and comprehensive data collected by MSG also aids the weather forecaster in the swift recognition and prediction of dangerous weather phenomena such as thunderstorms, fog, and explosive development of small, but intense, depressions, which can lead to devastating wind storms. On 29 January 2004 the first Meteosat Second Generation satellite MSG-1, renamed to Meteosat-8 once operational, commenced routine operations. In addition to the main optical payload SEVIRI (Spinning Enhanced Visible and Infrared Imager), Meteosat-8 also carries the secondary payload GERB (Geostationary Earth Radiation Budget) instrument. The launch of MSG-2 (renamed to Meteosat-9) took place on 21 December 2005. The launch of MSG-3 (renamed to Meteosat-10) took place on 5 July 2012. Meteosat-8 is stationed over the Indian Ocean, arriving at 41.5°E on 21 September 2016 and it took over as prime Indian Ocean Data Coverage (IODC) spacecraft on 1 February 2017 (replacing Meteosat-7). Meteosat-8 was retired from operational service on 1 July 2022 and finally decommissioned on 13 October 2022 after twenty years in orbit. The spacecraft was disposed of in compliance with ISO-24113 guidelines (although not designed with this in mind) having been raised 740km above the geostationary ring and spun down to 20rpm. The propulsion system was then passivated and the satellite deactivated. Meteosat-9 is also stationed over the Indian Ocean, arriving at 45.5°E on 20 April 2022 and it took over as prime IODC spacecraft on 1 June 2022 (replacing Meteosat-8). Meteosat-10 and -11 are located over Africa with various differences in operational configuration. Since 20 March 2018, Meteosat-10 provides an operational European 'rapid scan' mode service (the MSG RSS service first commenced in May 2008), with images of Europe every 5 minutes. Since 20 February 2018, Meteosat-11 provides the main full Earth imagery service over Europe and Africa (with images every 15-minutes). MSG-4 was successfully launched into space on 15 July 2015 at 18:42 local time on top an Ariane 5 Rocket from the Guiana Space Centre in Kourou, French Guiana. Like MSG-1, MSG-2 and MSG-3, MSG-4 was launched by Arianespace. The MSG-4 commissioning was successfully completed in December 2015 at which time the spacecraft was placed into in-orbit storage as planned, and renamed to Meteosat-11.

Secondary Payloads Meteosat-8, -9, -10, and -11 each carry a GERB Instrument, DCP capable service equipment and a Search and Rescue signal Processor (SARP) that is capable of detecting 406 MHz distress signals from emergency position-indicating radiobeacon stations. For SARP, see more under Cospas-Sarsat.

Third Generation ("MTG")

… excerpt ends here. Continue reading the full article.

Illustrations

Meteosat: Meteosat First Generation satellite — Meteosat First Generation satellite

Worked examples

Example 1 — a first encounter with Meteosat

Start with the simplest possible case. Write down what Meteosat claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Meteosat before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Meteosat ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Meteosat

In research: Meteosat appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Meteosat in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Meteosat is common in secondary-school and first-year university syllabi. It links to neighbouring topics Ariane commercial payloads, Data collection satellites, Earth observation satellites of the European Space Agency, so understanding it makes those chapters shorter.
In everyday life: Look for Meteosat outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Meteosat in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Meteosat means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Meteosat out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Meteosat in simple terms?

Why does Meteosat matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Meteosat?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Meteosat.