May 30,2008:
The U.S. Army's Raven UAV (RQ-11A)
flew 150,000 hours of combat missions last year (mainly in Iraq and
Afghanistan), and nearly 300,000 hours are expected this year. So far, over
9,000 Ravens have been delivered or are on order. So successful has the Raven
been, that the U.S. Air Force and the U.S. Marine Corps have adopted it (in
place of similar UAVs they had been using). SOCOM (Special Operations Command)
is also a big user. This little machine,
that looks like a toy, has revolutionized battlefield intelligence and made a
dramatic change in the way infantry leaders run battles.
The 4.2
pound Raven is inexpensive ($35,000 each) and can stay in the air for 80
minutes at a time. The Raven is also battery powered (and silent), and carries
a color day vidcam, or a two color infrared night camera. Both cameras
broadcast real time video back to the operator, who controls the Raven via a
laptop computer. The Raven can go as fast as 90 kilometers an hour, but usually
cruises at between 40 and 50. It can go as far as 15 kilometers from its
controller, and usually flies a preprogrammed route, using GPS for navigation.
The Raven is made of Kevlar, the same material used in helmets and protective
vests. On average, Raven can survive about 200 landings before it breaks
something. While some Ravens have been shot down, the most common cause of loss
is the communications link failing (as
the aircraft flies out of range, usually) or a software/hardware failure on the
aircraft. The flight control software has a "failsafe" mode, so that when the
radio link between aircraft and operator is lost, the aircraft will immediately
head for home (where it was launched from). Raven B has a rescue beacon in the
tail, that puts out a location signal. If a helicopter can be used, the downed
Raven can be quickly retrieved and repaired.
The Raven
B (RQ-11A), introduced this year, weighs a little more (4.3 pounds), but has
much better sensors, and the option of carrying a laser designator. Raven B
flight performance is better as well.
The big
advantage with Raven is that it's simple, reliable, and it works. A complete
system (controller, spare parts and three UAVs) costs $240,000. The UAV can be
quickly taken apart and put into a backpack. It takes off by having the
operator start the motor, and then throwing it. This can be done from a moving
vehicle, and the Raven is a popular recon tool for convoys. It lands by coming
in low and then turning the motor off.
Special Forces troops like to use it at night, because the enemy can't
see it, and often can't hear it as well.
The
controller allows the operator to capture video, or still pictures, and
transmit them to other units or a headquarters. The operator often does this
while the Raven is flying a pre-programmed pattern (using GPS). The operator
can have the UAV stop and circle, in effect keeping the camera on the same
piece of ground below. The operator can
also fly the Raven, which is often used when pursuing hostile gunmen.
While Raven is the most popular micro-UAV, several other models succeed
by doing basically the same job. By
quickly providing a top-down view of the combat zone, Raven has revolutionized
warfare. The infantry units love the fact that they control, and actually
operate, their own aerial reconnaissance force. Infantry troops and commanders
alike are very enthusiastic about Raven, because it takes a lot of the
uncertainty out of combat operations, and saves lives.