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MessageToEagle.com - Now, spying on people at home through the walls is easy.
Also find out what's going on behind closed doors - it's nothing particularly difficult. They will even know whether you're sitting or standing!
Scientists are already in possession of a radar prototype device that can track Wi-Fi signals in order to spy through walls. Their device identifies frequency changes to detect the moving objects.
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Wi-Fi radio signals are found in 61 percent of homes in the U.S. and 25 percent worldwide. University College London engineers Karl Woodbridge and Kevin Chetty have come up with an idea how to find out what's going on behind closed doors in urban environments, where nearly all homes and businesses have a Wi-Fi router setup and constantly emitting 2.4GHz or 5GHz radio waves. The method is similar to how radio waves are used to detect moving objects. When a radio wave reflects off of a moving object its frequency changes -- this is known as the Doppler effect. |
The tests were conducted by monitoring people inside a building using a 2.4-GHz passive multistatic receiver and a computer, to process the signals.
The receiver has two antennae -- one that tracks the base radio signal in a given area where a router or access point is setup, and one that detects the reflected radio waves emitting a new frequency.
Seeing through walls with a wireless router
By processing the data from both antennae, the system was able to accurately pinpoint where the people were through a 30.5cm-thick wall, what direction they were moving in and their speed.
The Wi-Fi radio wave frequency will also increase when an individual moves towards a router, and decrease as they move away from it.
The radar itself does not emit any signal and thus cannot be detected, making it ideal for spying or military operations.
Additionally, there is much that can be done to improve the device, especially its sensitivity in order to read the movements a person's ribcage makes while breathing. In this way, they can also deduce whether a person is standing or sitting.
UCL's radar is a stealthier device that makes use of readily available signals and can be packed away in a suitcase.
As such, it seems like a much more feasible choice for use in the field and the Ministry of Defence is already funding further studies to develop the system as a mobile tool to be used in urban warfare.
As much as 492 million households will have Wi-Fi by the end of 2012 -- that's more than a quarter of all households, market intelligence company Strategy Analytics reports.
So if you don't want to be spied on doing whatever it is you do in your home, you might want to invest in Institut Polytechnique de Grenoble's Wi-Fi signal-blocking wallpaper.
A team has published a paper demonstrating how a passive radar system can see through walls by reading Wi-Fi radio waves.
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