London, August 22 : British researchers have written a piece of software that can help harness upward-moving thermal air currents to keep un-crewed aerial vehicles aloft, with a view to saving precious fuel.

"It could increase the vehicles' endurance during surveillance missions," New Scientist magazine quoted Rhys Watkin of Roke Manor Research in Hampshire, a member of the team that developed the system, as saying.

The researcher has revealed that the software analyses video of the sky taken by an on-board camera to seek out nearby thermal currents, and then searches for the telltale grey, dome-shaped clouds that are formed by rapidly rising hot air.

Watkin says that the new system combines these details with real-time weather forecasts and computer simulations of air flow across the local terrain, so as to predict the locations of further thermal currents.

The research team also fed the software information from anecdotal reports by expert gliders, highlighting areas of rising air in specific locations and in various weather conditions.

According to Watkin, the software uses all of this data together with the aircraft's GPS coordinates during a mission, to plan a route that passes through as many thermals as possible.

So far, the system has only been used to suggest the path for a glider pilot to follow, but the team is developing software to enable an autonomous vehicle to fly solo.

In the future, Watkin hopes to add further software that will analyse maps of the local area and estimate how well ground surfaces emit heat, which also helps predict the location of thermals.

ANI