Sign up for NPL updates
Sign up for NPL updates

Receive regular emails from NPL to get a glimpse of our activities and see how our experts are informing and influencing scientific debate

Earth observation, climate and optical

TRUTHS: A climate and calibration satellite mission

NPL's metrology and calibration in space

Trusted Earth observation data to drive improved climate change modelling

TRUTHS is a climate focused satellite mission, led by the UK Space Agency (UKSA) in partnership with several European states. Delivered by the European Space Agency (ESA), it will facilitate improved understanding of changes in the Earth’s climate and the response to the worlds net zero agenda. This will be achieved through both its own observations, and its capability to improve the Earth observation (EO) system as a whole through in-flight cross-calibration of other satellites. TRUTHS will help deliver improved confidence in EO data gathered from space and the forecasts driven by this data.

TRUTHS stands for Traceable Radiometry Underpinning Terrestrial- and Helio- Studies and will enable an upgrade of the performance of the global EO system, both in space and on the ground. The mission aims to enhance our ability to estimate the Earth’s radiation budget by an order of magnitude, through direct measurement of the Earth’s incoming and outgoing radiation and enhanced performance of other satellites. Another key objective of the mission is to establish an SI-traceable reference data set which can be used to cross calibrate other satellites and improve overall data quality from the EO system.


TRUTHS will allow rigorous testing of model forecasts to support decision-making on climate adaption strategies and the success of our net zero activities. The mission will enable an improvement in accuracy of EO data, which will, in turn, drive a reduction in the time required for climate scientists to make unequivocal determinations of changes to the earth’s temperature. The mission provides 'benchmark'  measurements with uncertainties small enough that future change can be detected from a background of natural variability in as short a time as possible.

Contact us

Find out more

Missions objectives

SI traceability in-flight

Learn more about TRUTHS

Mission development 

Work with us

Our research and measurement solutions support innovation and product development. We work with companies to deliver business advantage and commercial success.
Contact our Customer Services team on +44 20 8943 7070