British engineers from University College London have
developed a radar system that can see through walls using the WiFi signals
generated by wireless routers. The system, devised by ‘Karl Woodbridge’ and ‘Kevin
Chetty’, requires two antennas and a signal processing unit, and it can be
place in a suitcase. Wi-Fi radio signals are found in 61 percent of homes in
the U.S. and 25 percent worldwide. Unlike normal radar, which emits radio waves
and then measures any reflected signals, this new system operates in complete
stealth. The radar itself does not emit any signal and thus cannot be detected,
making it ideal for spying or military operations.
You may also like The Fastest Ferrari is not a Car but a Train
You may also like The Fastest Ferrari is not a Car but a Train
1.
MOVING SUBJECT
When Wi-Fi radio waves bounce off a moving object, their
frequency changes. If, for example, a person is moving toward the Wi-Fi source,
the reflected waves’ frequency increases. If a person is moving away from the
source, the frequency decreases.
2. REGULAR OL' ROUTER
A Wi-Fi Internet router already in the room fills the
area with radio waves of a specific frequency, usually 2.4 or 5 gigahertz.
3. BASELINE SIGNAL
One antenna of the radar system tracks the baseline radio
signal in the room.
4. SHIFTED SIGNAL
A second antenna detects radio waves that have reflected
off of moving objects, which changes their frequency.
5. PERP, SPOTTED
By comparing the two antennas’ signals, the computer
calculates the object’s location to within a few feet as well as its speed and
direction.
0 comments:
Post a Comment