Researchers to build spectral imaging for nanosats
A multispectral imaging (MSI) device small enough to be installed on a nanosatellite is being developed in research led by the University of Strathclyde.
The study has received £719,000 as one of seven successful projects to secure funding from the UK Space Agency’s (UKSA) Centre for Earth Observation Instrumentation (CEOI).
Nanosatellites could play a larger role in Earth observation in the future, as they are cheaper to build and launch into space. A multispectral imaging device small enough to be installed on a nanosatellite could be used to monitor climate change, observe the activity of oceans, detect forest fires or track shipping traffic.
A commercial MSI satellite can measure up to 5.7 x 2.5 x 2.5m and weigh 2.8 tonnes. The new device could fit on a more affordable 4kg satellite of 10 x 10 x 30cm size and would orbit around 500km above Earth.
The researchers from Strathclyde’s Department of Physics are working with partners, led by product design company Wideblue, to produce the MSI technology. It will be designed, built and then tested by taking images during a flight attached to a drone.
Dr Daniel Oi, a physics lecturer at Strathclyde and lead researcher in the project, said: ‘Because of the novel way it operates, this instrument could open up ways of doing Earth observation which are different from conventional operations.
‘As nanosatellites are smaller, they don’t have the capacity to take a lot of data, process it and communicate it. The technology we are developing allows us to reduce the amount of data collected, with sensitivity to specific events or targets, and will enable more efficient monitoring of Earth.
‘Instead of a small number of very expensive MSI satellites, our instrument could be mounted on many nanosatellites to monitor the globe continuously. No satellite can be in two places at once, so operating in this way can enable the right data to be collected at the right time.
‘The early results of our research have been highly promising and the project is part of a significant and growing space industry in Scotland.’
The project’s partners also include two Strathclyde-based research centres, the Scottish Centre for Excellence in Satellite Applications and the Centre for Signal and Image Processing.
The project’s principle of operation – an innovation on a single-pixel camera – originated in research performed at the UK Quantum Technology Hub in Quantum Enhanced Imaging (Quantic), in which Strathclyde is a partner.
M Squared Lasers is developing a single-pixel camera for gas sensing as part of the Quantic programme, although the University of Strathclyde doesn’t state whether it is this camera that is being used in the nanosatellite project.
Single-pixel cameras differ from traditional cameras in that the image sensor is replaced with a single photodiode in front of a micro-mirror array, which encodes a series of binary patterns. Armed with knowledge of the patterns, an image can be deduced through data inversion.
M Squared’s Gas Sight camera is a single-pixel shortwave infrared camera operating between 1-2µm. The device has a resolution of 32 x 32 pixels and can run at frame rates of 20fps.
Greg Blackman wrote about M Squared’s single-pixel camera and other quantum imaging projects in the February/March 2018 issue.