Vital data to help address global challenges involving urban heat, agriculture, water use, and food security under changing climates, will shortly be collected over the UK and Europe in a unique international research collaboration. The work involves both the European Space Agency and NASA, and is part of an ESA-NASA bilateral agreement.
Coordinated by King’s College London and the Natural Environmental Research Council’s (NERC) National Centre for Earth Observation (NCEO), the NET-SENSE project will see an airborne sensing campaign conducted over parts of the UK and Europe using one of the world’s most sophisticated airborne thermal imagers, the Hyperspectral Thermal Emission Spectrometer (HyTES) from NASA’s Jet Propulsion Laboratory (JPL). HyTES will be operated for the first time outside of the USA, mounted alongside a series of companion airborne imaging systems from NERC NCEO and inside a specialised Twin Otter research aircraft operated by British Antarctic Survey (BAS) and normally flown out of Britain’s Antarctic bases.
HyTES accurately maps the temperature of the land surface at very high spatial detail from its airborne vantage point, using data collected in hundreds of different infrared wavelengths. Over cities these land surface temperature (LST) data can be used to map sources of heat and investigate phenomena such as the ‘urban heat island’, whilst over agricultural regions they can be used as inputs into methods for mapping ‘evapotranspiration’ from plants and soil, which is the rate at which water is being transferred from the land to the atmosphere and directly related to agricultural water use and some of the main influencers of crop stress.
NET-SENSE will conduct new science by collecting airborne data over existing sites of agricultural experiments run by collaborators in the UK (NERC Centre for Ecology and Hydrology), as well as others in Italy and Germany, where ‘ground-truth’ measurements of LST, evapotranspiration, and crop stress will be made by King’s College London/NCEO alongside these local investigators. Importantly though, the campaign will also provide information crucial for helping plan a future European remote sensing satellite – the Land Surface Temperature Monitoring (LSTM) mission – that is currently being considered for inclusion in the next iteration of Copernicus, the European Union’s flagship Earth Observation Environmental Monitoring Programme.
UK scientists from NCEO are some of those leading the work with the European Space Agency (ESA) to specify the exact measurement characteristics that LSTM should have, such as which wavelengths to measure in, the time of day the satellite should overpass, and the spatial detail the measurements should be made at, all from a satellite orbiting hundreds kilometres above the Earth. Equally, the NET-SENSE data will support validation of LST and water use information being generated now by an existing NASA mission – ECOSTRESS – which is operating on the International Space Station, and will aid development of a proposed future NASA Surface Biology and Geology (SBG) mission targeting similar applications. In these ways, NET-SENSE is providing data that will help influence current and future EO missions, as well as providing information that will contribute significantly to current scientific studies.
Martin Wooster, Professor of Earth Observation Science at King’s College London and NERC NCEO, is leading the campaign organising from the European side. He said: “The Space Agencies NASA and ESA have provided a phenomenal opportunity to operate JPL’s HyTES thermal imaging instrument over the UK and Europe for the first time ever. Flying HyTES alongside our UK instrumentation offers a unique data collection capability that will provide both new science and information that can really have a strong influence on the design of the proposed new LSTM satellite.
“Examining our planet and its environment for the ultimate benefit of people is so important with the ever-pressing global challenges we face, and remote sensing from satellites is a key way to provide a consistent, global view that we can use to track and respond to both short and long-term change.”
The NET-SENSE project has already seen the HyTES instrument travel to the UK from NASA’s JPL in Pasadena (California), and be fitted to the British Antarctic Survey’s Twin Otter aircraft, ready for the first flights across the UK and parts of Europe to commence in mid-June.
The research team hope that over the next two years, similar flights will be carried out across other parts of the UK and continental Europe, with the LSTM satellite being designed and built over the next decade if it is selected for inclusion in the next iteration of the Copernicus Programme.