The electronic eyes that warned of the big snowfall that has collapsed half of Spain

The weather satellites anticipated what was going to happen. Predictions made by meteorologists from the State Meteorological Agency (AEMET) had announced more than a week ago that the Filomena storm would cause an intense snowstorm in a large part of Spain, as it happened. 

AEMET professionals' forecasts have been based on the results produced by the sophisticated algorithms and numerical models they work with day after day, which are continuously fed with data from land stations, ships and marine buoys, but especially with those provided by one of their main working tools, satellites. 

Packed with sophisticated instruments and designed specifically to draw the evolution of meteorology and climate on a local, regional and global scale, these platforms populate space in different orbits and at different heights, so that technicians can draw conclusions and make their predictions as accurately as possible. "They have even managed to calculate the accumulation of snow, for example, in Madrid, and express it in centimetres", says the expert Rubén Vázquez. 

On the old continent, EUMETSAT, the European Organisation for the Exploitation of Meteorological Satellites, which has been directed by the British Phil Evans since January 1, is the owner and responsible for operating a total of seven platforms with total meteorological dedication. Three form the constellation MetOp and four the so-called Meteosat Second Generation (MSG), whose wizards are renamed Meteosat when they begin service. The latter are well known to the citizens of the old continent because they are often mentioned by TV and radio weather reporters.

MSGs watch on a dozen channels, four in the visible spectrum and eight in the near infrared, some with a resolution of less than two kilometres. They have the SEVIRI camera, which is capable of scanning the entire Earth in 15 minutes or half the hemisphere in five minutes. They also incorporate the GERB radiometer, which observes the whole of the Earth every five minutes in the visible and infrared spectra and measures the solar radiation reflected by the Earth. They work in pairs, so that while one captures images of the whole planet, the other scans Europe.

The result is that images transmitted to the state meteorological services of European nations offer high quality and a high level of detail. With their analysis, European agencies such as the Spanish AEMET, Météo France, the Portuguese Instituto do Mar e da Atmosfera or the German equivalent Deutscher Wetterdienst are able to produce short or very short term, real time weather forecasts and also numerical climate prediction and monitoring models for Europe, Africa and the North Atlantic.

Catalogued as Meteosat-8, 9, 10 and 11, cylindrical in shape and weighing two tonnes, they are primarily responsible for observing the Earth's atmosphere 24 hours a day, which they do from an altitude of 36,000 kilometres and always over the same area of the Earth. The oldest of the four is Meteosat-8 - in orbit since August 2002 - which will remain active until at least 2022, unless there is an unforeseen technical failure. Meteosat-11, launched in July 2015, is the newest and is expected to remain active until at least 2033, more than 50 years after Meteosat-1 was put into orbit. 

The European Space Agency (ESA) and EUMETSAT are already working together on Meteosat Third Generation or MTG, which is equipped with 16 channels. On this occasion there will be six satellites of two different types, all built by the French-Italian company Thales Alenia Space, with a key technological contribution from the Spanish space industry in their design, development and manufacture, which accounts for 12% of their value.  

Airbus Space Systems has made the thermal protection of the satellite and the wiring of the main SEVIRI instrument a reality. Airbus CRISA has been responsible for its Functional Control Unit and SENER has manufactured important electronic assemblies. And Alter Technology has carried out the selection, testing and supply of all the electronic components.  

GMV has contributed the software of the instrument's operational processing system and the technical support for its users; Indra has supplied the satellite control and tracking system installed in the INTA space station in Maspalomas (Gran Canaria), while Thales Alenia Space España has worked on the simulation of the data transmission chain and provided the electronics for image transmission.  

The Operational Meteorological Satellite Programme (MetOp) is EUMETSAT's contribution to a cooperative project with the US National Oceanic and Atmospheric Administration (NOAA) to monitor climate change and provide new detection capabilities to improve weather forecasting.  

The MetOp family consists of three satellites placed in polar orbit synchronized with the movement of the Sun. This means that its passage through a given point on Earth always occurs at the same time, a key aspect in determining the progression of temperatures in one direction or another. To achieve this, instead of being located 36,000 kilometres from the Earth like the Meteosat, they are all placed at an altitude of 830 kilometres, approximately the distance from Murcia to Santander. 

With a take-off weight of just over four tonnes, MetOp-A, the first in the series, was launched in October 2006, followed by B in September 2012 and C in November 2018. A wide range of instruments, sensors and cameras travel on board, ensuring high-quality data for medium- and long-term weather forecasting and climate monitoring.

With an estimated half-life of 14-16 years, a second generation or MetOp-SG is already underway, with the first copy due to fly into space in 2021 to ensure continuity of data supply through new atmospheric probes, optical imaging cameras and microwave sensors. The programme comprises six satellites in two different configurations (A and B) and its construction was assigned in 2014 to the European multinational Airbus. Most of the Spanish companies participating in the MTGs also participate in MetOp-SG. 

The control and monitoring of EUMETSAT's satellite fleet is carried out from the German city of Darmstadt, which houses ESA's European Space Operations Centre (ESOC). As an intergovernmental organisation made up of 30 European nations, the Spanish representation is provided by the aforementioned AEMET, which belongs to the Ministry of Ecological Transition and Demographic Challenge, a portfolio headed by Teresa Ribera.