SECTION 6: CONDUCTING A SWEEP
REI
OSC-5000E
96
The sound source provides many benefits:
It masks the noises associated with testing and inspection sweep activities.
It provides a good reference sound source for the OSCOR to perform threat
correlation.
It may activate sound-controlled devices.
If a built-in speaker system is used to flood an entire area (several offices, a floor
of a building or an entire building), the OSCOR will correlate on threats that may
be located anywhere in the area as long as the bug’s transmitted signal is of
sufficient strength. In other words, with a known sound source flooding the
building, the OSCOR can sweep many rooms at once.
If the known sound source is fed directly into the OSCOR using the external
reference input jack, then the correlation sensitivity is increased, which further
increases the OSCOR detection range.
Considerations for Infrared and Laser Threats
Since infrared signals cannot be transmitted through walls, infrared bugging devices are
typically placed near windows or outside the building with a wired microphone in the
building. For this reason, the OSCOR should be placed near a window when sweeping
for infrared threats. The drapes or mini-blinds should be closed to make sure no one
observes your activities. If the windows are large, it may be necessary to move the
OSCOR to several locations when sweeping for infrared signals. If there is an infrared
transmitter in the room of interest, some of the infrared signal will be reflected off the
window, which provides additional opportunity for detection. The OSCOR should also
be taken outside (during the night to prevent the sun from interfering with the OSCOR
infrared detector) and 20 to 30 ft away from all windows. (All window coverings within
the building should be opened for this type of sweep.)
NOTE
: When sweeping for infrared signals outside a building the Correlate Mode cannot
be used accurately unless the sound source from within the building can be fed into the
OSCOR audio input. This can be accomplished by using a portable radio or Walkman,
and a common radio station as the sound source. As long as the same music within the
building is patched directly into the OSCOR, the Correlate Mode will function normally.
NOTE
: When used outside the building, the OSCOR is not in a covert mode.
NOTE
: It is not practical to search for infrared signals outside high-rise buildings even
though they may be received from adjacent high-rise buildings. However, infrared is
easily diffracted by windows and may still be detected within the target environment.