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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