EO Detective

Investigating the Earth from Space

About Earth Observation

Satellite with single solar panel flying over Earth

Credit: ESA/ATG medialab

What is Earth Observation?

Earth Observation (EO) scientists collect information about the Earth – the land, the sea and the atmosphere – using sensors carried on satellites, aircraft, ships, buoys floating on the ocean, and thousands of weather stations around the world. There is now a great deal of data available and scientists are finding more and more ways to use it to study our planet and make predictions about its future.

What is it used for?

Weather and climate

Satellite image of UK. Mostly clear skies, heavy cloud to the north.
NERC Satellite Receiving Station, Dundee University, Scotland

We are all familiar with satellite images from weather forecasts. But satellite instruments can do more than show where clouds and weather systems are.  They can give all sorts of information such as land and sea temperature, wind speed and rainfall. Meteorologists need this data from all around the world to build computer models that they use to make their weather forecasts. Climate scientists also use this data: their focus is investigating longer-term patterns and changes to the Earth’s natural systems.

Ocean temperature and colour

Swirls of plae blue on bright blue background

The ocean plays an important part in controlling climate. Using satellite data we can map the temperature of the entire ocean at frequent intervals to see how heat is moving around the planet. Satellites such as ESA’s Sentinel 3 are very sensitive to changes in colour caused by the presence of plankton: this is another important input into climate models.

Forests and habitats

Trees in Rainbow colours
M. Disney, NCEO/University College London and A. Burt, University College London

Satellite images show large areas of the Earth’s surface at one time, making it easier to spot changes such as deforestation caused by illegal logging. It is now also possible to measure the density of trees, and therefore the amount of carbon they capture and store, using remote sensors. This means climate scientists can keep better tabs on how carbon flows around the planet, and give the government better information to help it keep international carbon treaties.

Map showing rate of ice flow on Antarctic peninsula
Contains modified Copernicus Sentinel data (2015), processed by Enveo


Satellites such as Sentinel-1A & 1B use ‘active sensing’ techniques, similar to radar, to help monitor not just the extent of ice in glaciers and at the poles, but also the ice thickness and how fast it moves.

Natural disasters

Man in a respiration mask, next to an instrument in smoky haze: fire in the background.
NCEO/Kings College London

Active sensors also allow scientists to map ground and sea level height with great sensitivity. Since satellites can scan places that are otherwise inaccessible, information from them is used to monitor environmental changes during forest fires, earthquakes, volcanoes, floods and so on and is now a crucial tool for emergency services and rescue teams.

Human activity and impact

EO data is used in many ways to support businesses and explore our impact on the Earth. For example, it can be used to monitor air quality and other forms of pollution such as effluent from industry and light from cities. The mining and oil industries use it to identify sites that might contain new mineral or oil reserves. Farmers use it to monitor the health of their crops and to irrigate and fertilise only those plants that need it. Of course, this ‘precision agriculture’ also makes use of accurate weather forecasts and, when combined with climate data, it has potential to increase long-term food security in many parts of the world.

Red circles on a green ground, concentrated to left of picture. Lines through area.
Copernicus Sentinel data (2015)/ESA

What is the role of NCEO?

The National Centre for Earth Observation (NCEO) brings together scientists leading many of these fields and supports efforts to process, analyse and share the vast amounts of data now available. We provide training and access to instruments. NCEO is a research centre of the UK’s Natural Environment Research Council (NERC), which recognises that we can advance UK research into the Earth’s natural systems more effectively by working together. Our network of expertise includes academics, engineers, industry partners and space agencies, including the UK Space Agency. We are involved in planning new satellite missions and link to international organisations such as the European Space Agency (ESA) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT).

Man in suit leaning on case containing a satellite

We are passionate about the importance of our research to society; EO science is increasingly beneficial for a range of applications.

Professor John Remedios,
Director of NCEO


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