981. Micro-UAVs Possible in Near Future

by Dale Kuska

Special to the American Forces Press Service



	MONTEREY, Calif. -- A Navy SEAL creeps silently through

dense bushes, and approaches a structure with American

citizens held captive inside. He needs to see inside the

building to find how many hostages there are and exactly

where they're located, but he cannot simply walk up to the

building.

	He reaches into his belt and opens a small canister to

release a micro-unmanned aerial vehicle -- a two-inch rotary

aircraft that can fly quickly into the building to collect

data and assess the situation.

	Sounds futuristic, but vehicles like this are

approaching reality, and at the Naval Postgraduate School,

here, a two-man team is working to bring such vehicles to

life.

	"Our particular vehicle is remotely-piloted, meaning

there will be someone on the ground providing the control,

like a remote-controlled car. There would be a camera inside

to provide real-time video information, which gives the

operator the ability to see where he's flying," said

electrical and computer engineering Professor David Jenn,

who's been working on the project with doctorate student Bob

Vitale.

	Surveillance during hostage situations is just one use

for a micro-unmanned aerial vehicle. It could also inspect

hazardous areas, such as an area contaminated by a chemical

attack, or other instances when sending humans would be too

risky. Plus, its small size gives other advantages.

	"It would be portable, so it can be carried on a SEAL's

belt, for example, and, when he needs it, he can simply open

the canister and flies it off," Jenn said. "These things are

very small, they're covert, they are very difficult to see,

and even if you do see them, they're very difficult to shoot

down."

	The primary focus of Jenn's research is to find an

innovative power source for such a small aircraft.

	"If you use a battery, it's too heavy," he said.

"Besides, batteries will not provide a lot of power for a

long duration of time. (In our research) we're using an off

board source of energy. An antennae would track the vehicle

and provide a microwave beam to provide energy to the

vehicle. The vehicle receives it, rectifies it, then uses

that energy to power the motor.

	"One of the biggest advantages of using microwave power

is that you can make these UAVs smaller and smaller. With a

battery, if you continue making it smaller, you lose power,"

Jenn explained.

	Jenn and Vitale's approach for obtaining power is

ground-breaking.

	"We've never seen anyone transfer power in this way

before. In the past, people have used a microwave dish

antennae with a large, flat panel suspended over it to

gather energy. With a micro-UAV flying, this panel wouldn't

work, because once the UAV flew off to the side, it wouldn't

be able to receive energy and therefore would fall to the

ground. The antennae we're working on is multi-directional,

so it can continue to send energy no matter where the micro-

UAV is," said Vitale. "We've also been able to use the body

of the aircraft as an antennae."

	Jenn and Vitale's goal is to fit required sensors into

a small, graphite canister weighing no more than a piece of

paper, so these micro-unmanned aerial vehicles must do more

than maximize use of space.

	"The types of sensors DoD would like to see in here are

a video camera, radiation sensors, chemical sensors, and

maybe even [Global Positioning System]," Jenn said. "There's

also talk of using these as communication relays. All this

equipment can be packaged together, but it's the weight that

creates a problem."

	Even with weight as an issue, these tiny vehicles are

making progress.

	"We've already demonstrated we can transfer power with

microwaves. We've performed tests on the safety issues of

microwaves, and we've shown that having multiple ground

stations [sending microwaves] is the best possible method,

said Jenn. "Now we plan to show how we can power these UAVs

using radar systems -- systems the Navy already has."

(Kuska is a writer at the Naval Postgraduate School.)



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