The motor begins to hum and the propellers begin their increasingly rapid revolutions. A gentle upward tilt of the joystick by the owner and the rotocopter is airborne — slowly elevating as it drifts over a cornfield to capture hundreds of images that will be processed and analyzed.

In the not-so-distant future, farmers wanting to scout fields for diseases and pests, spot spray for weeds or obtain 3-D maps of their farm ground will be turning to tiny autonomous helicopters or planes to do the job.