Laser Surveillance Laser Listening

Laser Surveillance Laser Listening

Post by NSA TORTURE TECHNOLOGY, NEWS and RESEARC » Thu, 07 Apr 2011 06:59:57

http://www.gcomtech.com/ccp0-prodshow/laser-surveillance-laser-listen...

Laser Surveillance Laser Listening

Laser Surveillance theory of operation: The GCOM Laser Listener consists of
a highly focused light sent over a distance and beamed onto the surface of a
window of a building such as an office room, hotel room, apartment room,
house, etc. This highly focused laser light or infrared light encounters a
series of micro-vibrations on the window's surface. It is these vibrations
that enable laser listening to occur. The movements of windows originate
from speech conversations as well as other sounds inside the targeted room.
The window vibrations are caused by oscillating frequencies from sound waves
that emanate from speech and conversations of the people in the room.  Just
like a diaphragm of a microphone, the window also vibrates and it is this
vibration that the Laser Surveillance System picks up on.

The infrared light of the laser listener then reflects off of the surface of
the window and back to an optical receiver. This optical receiver is
connected to an electronic demodulation system that converts the optical
signals produced from the infrared light into sound waves. These sound waves
are then filtered and can be made available for listening in real time, or
connected to an external recorder for future review.

Q:  How is the sound quality of Laser Surveillance?
A:  Under ideal conditions, the laser listener has very good sound quality.

Q:  Is the system easy to set up?
A:  Yes with practice. The first time always is difficult. That is why the
user is advised to conduct a few practice tests in order to become familiar
with mounting and aligning the GCOM Laser Surveillance System for optimum
results.