Temperature and humidity scientists at UK-based National Physical Laboratory (NPL) have developed a new method to take 3D thermal images of satellites.

Developed for the European Space Agency (ESA), the new technique will enable measurement data to be compared with thermal models in a better way.

First implemented in 2D by the research team, the new 3D thermal imaging technique allows thermal pictures to be taken on the ground and provides additional information.

It also allows scientists to model pre-launch satellite behaviour and improved measurement resolution, as well as reduce the number of thermocouples required.

"Accurately measuring the geometrical form and thermal distribution of a satellite has been a significant measurement challenge."

NPL researcher Rob Simpson said: "Accurately measuring the geometrical form and thermal distribution of a satellite has been a significant measurement challenge.

"But we're very pleased with the early results."

Switzerland-based 3D measurement company PhotoCore and London, UK-based management consultancy PSI-tran are also involved in the project.

By producing accurate and traceable geometrical and thermal information from the satellite structure, the new technology also helps in measuring emissivity, inter-reflections and background radiation.

Space scientists traditionally use sensors called 'thermocouples' to measure temperature.

However, the technique is often considered impractical and can create major difficulty for space flight due to the increased weight of the satellite.

In 2009, the research team at NPL along with ESA created a 2D thermal imaging system that could image inside a vacuum.

Image: Thermal image of TEDY (test satellite) 1/3 scale mock-up at NPL. Photo: courtesy of NPL Management.