Land & Earth Observation

More than half of all Global Climate Observation System (GCOS) Essential Climate Variables (ECVs) (atmosphere, ocean and land) can only be measured via remote sensing from space and another quarter require at least some space-based observations. This section includes metrology support for all remote sensing techniques from all platforms including satellites, aircrafts, drones and surface-based remote sensing, along with observations that provide in situ validation of remote sensing techniques.

This section also covers the metrological needs of land-based in-situ observations. Land and its biosphere provide a natural sink for more than half of all anthropogenic CO2 emissions. Therefore, its continued health and sustainability is critical for achieving the net zero carbon goals needed to stabilise our planet. On the other hand, land can also be a source of greenhouse gas emissions, with potential tipping points such as methane release from permafrost in the cryosphere.

In this theme, our activities include developing standards and methods for the pre-flight and in-flight calibration and validation of sensors using remote sensing methods across the electromagnetic spectrum, remotely or locally deployed. It also covers the metrology needed to assign quality metrics to derived information products, i.e. accounting for retrieval algorithms, sampling and timescales that might span decades (historical and future). We also look to support those making or interpreting measurements of all land-based parameters - whether it be through laboratory calibrations or supporting field measurements in campaigns and networks.

Improving atmospheric data

Spectro-analytical techniques are used to identify and quantify concentrations of greenhouse and other gases in the atmosphere. These techniques are based on the unique spectral ‘finger prints’ generated by molecular interactions with specific radiation selected in the near and mid infrared wavelengths of the electromagnetic sp...

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Improving climate modelling accuracy

Observations of the Earth’s atmosphere, oceans and land from space are vital for climate studies. These are built into models used by climatologists to understand and predict how weather patterns are changing. International initiatives such as the Quality Assurance Framework for Earth Observation (QA4EO) are increasing this com...

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Seeing ocean colour from space

To analyse and assess ocean colour requires satellite measurements sensitive enough to distinguish small changes in the little light reflected by the ocean from the brighter background light reflected by the atmosphere. Radiometers, the instruments that measure ocean colour, are calibrated pre-launch, but due to demanding accur...

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Confidence in climate data

The instruments used on board satellites to make measurementsof key climate variables are calibrated prior to launch to ensure their accuracy. However, instrument performance can change during launch into space, and once in flight instruments operate in a very different environment to that in which they were calibrated. Changes...

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Ensuring accuracy in the upper atmosphere

Recognising this need, organisations including the European Space Agency (ESA) now require the instrumentation they use to meet the Quality Assurance Framework for Earth Observation (QA4EO) guidelines, which specify the need for measurement traceability. However, while carefully calibrated on the groundprior to launch, Earth ob...

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