Tiny unmanned craft — some fly, others dart under the waves — are being developed at the University of Florida. They can spy on hurricanes at close range without getting blown willy-nilly, while sensors onboard collect and send in real time the data scientists need to predict the intensity and trajectory of storms: pressure, temperature, humidity, location, and time. Professor Kamran Mohseni said people ask how the miniature flying machines — just 6 inches long and about the weight of an iPod Nano — can take on one of the monster storms. “Our vehicles don’t fight the hurricane; we use the hurricane to take us places,” said Mohseni.
The aerial and underwater vehicles can be launched with commands from a laptop hundreds of miles from the eye of a hurricane. Mathematical models predict regions in the atmosphere and ocean that can give the vehicles a free ride toward their destination. Once in the vicinity, they can be powered off to wait for a particular current of wind or water. When they detect the current they need for navigation, they power back on, slip into the current, then power off again to conserve fuel as the current carries them to a target location. The devices are a departure from current technology, which uses hurricane reconnaissance aircraft to punch through a storm’s eye wall and release dropsondes, sensors that free-fall and might or might not collect helpful data. Underwater data are even more difficult to collect today, although just as important, considering that the warm, moist air on the ocean surface provides fuel for hurricanes.
The prototypes produced at the institute are about $250 apiece and are too small and lightweight to cause damage when they hit something, a big consideration in hurricane-force winds and waves. Mohseni does not use a landing strip to test the aerial vehicles; he just tells them to crash, picks them up and flies them again. The carbon fiber shell of the aerial vehicles is wafer-thin but resilient.
The vehicles also are smart. Mohseni developed a cooperative control algorithm that allows them to form a network and learn from the data they take in, for example, by adjusting their course when needed. This feature makes them useful for applications beyond hurricanes.
Extreme environments, such as the polar ice caps, are difficult and hazardous to measure with standard technology. Mohseni said heat transfer through polar ice between the ocean and the air goes almost completely unmeasured today but could be safely measured with the aerial vehicles, which can be launched from a laptop aboard a ship and send back climate data in real time.