European Space Agency (ESA) scientists are working on a system to detect marine waste from space in a bid to help tackle the “millions of tonnes” of plastic left in oceans each year.
Researchers are looking to use direct optical measurement of “seaborne plastic waste” in areas of high concentration, using satellites.
Currently, satellite maps are in use which provide simulations of litter across Pacific, Atlantic and Indian Oceans.
Yet scientists hope the new technology will help them to move away from simulations and gain a more accurate insight into litter concentrations at sea.
It is also hoped that this new method will have more impact on the public and policymakers, by providing images based on “actual measurements”.
Some 10 million tonnes of plastic litter are dumped in the waters annually.
Paolo Corradi, who is overseeing the project at the ESA, said: “What we are now looking at in this new project is to assess the feasibility of direct optical measurement of seaborne plastic waste from satellites.
“We’re not talking about actually spotting floating litter items but instead to identify a distinct spectral signature of plastic picked up from orbit, in the same way that processing software can today pick out concentrations of phytoplankton, suspended sediments and water-borne pollution.
He added: “Monitoring is not a goal in itself, but a means to show the scale of the problem, and start to try to solve it.”
Plastic has “specific infrared fingerprints” to help differentiate it from other items of rubbish, he added.
The project will reveal the requirements needed for a satellite which detects plastic litter by picking up those infrared fingerprints, in a similar way to how it is identified on a refuse conveyor belt.
Work on the project began in September 2017 and draws on expertise from marine litter experts and specialists in remote sensing.