Welcome to the
"Co-veillance" Section
of
Doktor Jons

Guide to Closed Circuit TV (CCTV)

So would you like to play "Spot the CCTV Camera?". Eagle eyed visitors may recognise the profusion of street furniture, surrounding a single heritage dome camera keeping watch over part  of Londons' prestigious Oxford Street shopping area.


A Collection of Covert Considerations - continued

Almost unheard of but still a viable technique, is to transmit the video as a “multiplexed” signal over the buildings existing mains electric supply. This (although expensive) has the advantage that a camera can be set up anywhere in the building, and of course monitored practically anywhere else, provided the mains power sockets are on the same circuit.

Whilst wireless transmission will always carry some small risk of creating problems, it should perhaps not pass unremarked. Transmitted signals can under some conditions, adveresly affect or interfere with other electronic equipment already in use at the same location.

So the obvious risk of using a transmitted covert camera in an office environment with perhaps fifty networked
and stand alone computers in operation, must be adequately assessed before the camera is left to do its job.

It’s perhaps also worth mentioning that commercially available signal adaptors, can be used to convert a computer display into a composite video output, so that whatever activity is taking place on the computer screen, can be transmitted and recorded along with the hidden camera imagery.

This technique is particularly effective for addressing the problems of computer based fraud, and offensive or threatening e-mails.

One possible way of enhancing the covert camera, is to employ a “scrambler” or codec which will render the transmitted signal unviewable, unless the complimentary decoder is used to receive the images. These devices work well on both cabled and transmitted systems, but unfortunately .... at a price!

Video Motion Detection (VMD) can offer a very useful technical enhancement, providing an indication of activity on a normally static image, although VMD triggered recording is most certainly not recommended for use in situations requiring irrefutable evidential quality recording.

The fact that 'inactivity' is missing from the recording, could compromise the integrity of the remaining evidential bits.

 

Continued >

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