Seeing and listening through a wall: radio waves and optical fibers


A research team from University of Utah is at work on a project that allows usage of a small network of wireless radio transceivers, in order to detect movements of people on the other side of a wall.
Thanks to this detection system, based on the RTI (Radio Tomographic Imaging) concept which allows the images to be send via airwaves, police, surveillance forces and firemen will be able to detect intruders or casualties trapped inside a building, by simply placing these small transceivers in the area.

The RTI system is basically reading the “shadows” of radio waves when they pass through a person in motion, and based on these shadows it builds an image. In an experiment that has been used as an example, scientists have created a small network with 28 transmitters, placing them in rectangular shape in a room and in the garden outside the house.

At this point, the radio signal strength was measured, first when the rectangle was empty, and then with a person inside it. By transferring the relevant data to a computer with a calculation software, a very blurred image, resembling a shadow, is created by this software.
By improving method and detection systems, it has been possible to detect human movements on the other side of a wall.
The network used is not a normal Wi-Fi network such as the one normally used at home for computers, so it can not be detected by devices using such protocol, and can be used for surveillance purposes. The Zigbee communication protocol used for this system can generally be found in automated domestic appliances.

Since it is based on radio waves, it can also work in the dark, and due to the very blurred image that can be obtained, it does not pose any kind of threat under the privacy point of view. In order to obtain images with a better quality, an optimal solution is the usage of optical fiber devices, such as for example a fiberscope, made up of a tiny cable, only 2.5 mm in diameter, which carries a drill bit camera at one end.

Just dig a hole in the wall and insert the cable, and maybe connect the fiberscope to a digital video recorder to record high quality images inside a room. Alternatively, a non invasive option, used only to listen through the wall to what happens in the room nearby, is the usage of a wall microphone.

A wall microphone is basically a technologically advanced version of our doctor’s stethoscope, equipped with high sensitivity microphones and connected to a power amplifier, which makes it capable of listening through brick walls without arising any unnecessary suspicion or attention. Once again, in this case you can use a digital recorder to store any information or evidence gathered.

Video surveillance, a booming business in the Russian marketplace


The Russian government seems to pay particular attention to Internet technologies. In fact, president Medvedev, in his latest speech, has more than once made direct references to the development of broadband access, which should be widespread even in the most remote corners of that big country, paying particular attention to electronic documentation management and remote education programs.

This concerns the public sector and services to citizens. As far as the private sector is concerned, the Internet development will be useful, among other things, to increase the security level in the cities, by lowering costs at the same time, thanks to IP video surveillance.

Currently, the percentage of surveillance systems using Internet to transmit data and images ranges between 5% and 7% of working surveillance systems. The target is raising this share to 15% as soon as possible, by relying on the fact that, in times of crisis, the video surveillance in Russia is actually showing a dramatic increase, with an estimated growth in 2009 of 20% towards previous year.

Of course, development of Internet based surveillance and monitoring solutions must be supported by an equal development of infrastructure, especially in smaller towns. If in Moscow the percentage of broadband access is around 85%, in the rest of the country it ranges between 20% and 40%.

The struggle to gain market shares is taking place in three sectors: IP video surveillance, corporate communications and VoIP telephony, with big name operators launching their high-end products, such as high-resolution surveillance cameras, on the Russian market; on the other hand, though, the network infrastructure may not be able to support such an advanced technology.

The struggle just started, will the end user reap the benefits? Time will tell!

Video monitoring kits: a security professional at work

Video monitoring kits: a security professional at work

Today we all stand as a part of spying and security industry in one way or other, everyone at some point of time realise the need of video surveillance may be to maintain a defended intimate shelter or to fade out suspicions. The video monitoring kits are quiet a craze these days, most include disguised high resolution cameras, digital video recorders, audio microphones and USB cables to transfer data with ease to a connecting screen or computer. Most public places such as shopping malls, hotels, busy roads, offices apply these monitors to anchor video surveillance to achieve orderly conduct and prevent spanking criminal or illegal acts. Also available in varied sizes and shapes particularly for purpose of spying. The appliances usually come loaded with inbuilt memory with a feature of expandability to even accommodate more footage at a time.

With hi-tech advancements rising every day that goes by; the covert features including night vision have too upgraded the system and reluctantly role play of a security scout working day and night. These are designed to work on various frequency channels ranging to a maximum of 2500 MHz To aptly gel with other instruments the video clips are usually stored in AVI format and audios in either MPEG or mp3 format. With finer technical details the video monitoring kits have become the need of the hour. After all, none of us ever want to live in a mindset that’s always worrying on security and vulnerability.