NASA has completed a remote-sensing demonstration using the AeroVironment Pathfinder-Plus solar-powered unmanned air vehicle (UAV). The mission produced digital images of a coffee plantation in Hawaii to help growers select the ripest field.

Dr Stan Herwitz, principal investigator for the UAV Coffee Project, says: "During the flight we assembled clear-sky images, even though the plantation was never completely cloud-free." The mission involved flying in civil airspace. "The UAV was treated like any conventionally piloted aircraft by air traffic controllers," he says.

The 11.5h mission on 30 September involved a 4h flight at 20kt (37km/h) and 21,000ft (6,400m) over the Kauai coffee plantation, with the Pathfinder-Plus downlinking more than 300 high-resolution digital images. Using a combination of pre-planned flight lines and spontaneous remotely controlled manoeuvres to guide the UAV to cloud-free areas, the team was able to produce a mosaic image of the plantation showing the relative ripeness of the coffee field.

"It would not have been as exciting had it been a clear sky," says Herwitz, highlighting the "mobile satellite" capability of the long-endurance UAV.

Source: Flight International