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ISIS Q&A
What are the laws and regulations with regard to video or audio surveillance?
The government defines a surveillance operation as an event
during which the activities of a particular individual are observed and
documented.The Fourth AmendmentUnder the Fourth Amendment of the U.S.
Constitution, "The right of the people to be secure in their persons, houses,
papers and effects, against unreasonable searches and seizures shall not be
violated."Plain View DoctrineThis doctrine generally states that anything
that is visible to officers in a public area they lawfully maintain is
evidence that is admissible in a court of law.Expectation of PrivacyA
reasonable expectation of privacy is used to determine whether the
Government's (i.e. Law Enforcement)actions with regard to obtaining evi! dence
are lawful. This expectation must be satisfied by an affirmative response to
these questions: 1) Did the subject of the surveillance maintain an
expectation that their private? 2) Is the expectation one that society
recognizes as being reasonable?Audio and Video SurveillanceAt the time of
this publishing, Federal and State laws regarding covert surveillance appear
to be more clearlydefined with regard to situations surrounding the use of
wire, oral or electronic intercepting devices, than they do with regard to
the recording of video images.VideoCurrently the laws governing the use of
video (image) surveillance appear to be less specific than for audio. Above
all, the "reasonable expectation of privacy" should apply as a guideline. In
general, employers can monitor the activities of their employees to uncover a
variety of issues, including theft, substance abuse, vandalism, corpor! ate
espionage and other illegal or unauthorized activities. Central to this
concept is that theworkplace is not a location in which, under normal
circumstances, persons consider their actions private. Onthe otherhand,
surveillance in the workplace must not intrude on those areas where persons
consider theiractivities private. A restroom is an example of such a place.
In some cases, the public presentation of a Warning Notice stating that a
particular area may be under surveillance tends to mitigate a person's
expectationof privacy.AudioUnder Section 2512 of the U.S. Code, manufacture,
distribution, possession and advertising of wire, oral or electronic
communication intercepting devices is prohibited. Excluded from this law are
officers or employeesunder contract to the Federal government, a State or
subdivision thereof. This is taken to mean that, with properauthorization,
Law Enfor! cement agencies may be able to use covert audio surveillance. Each
agency should review the laws for their jurisdiction before using audio
surveillance. Clearly, covert audio surveillance is not permissible in the
private sector.DisclaimerThe above statements are considered general
information and are not to be construed as statements of law ISIS cannot be
held responsible for the interpretation of laws regarding video and/or audio
surveillance. All persons, groups or agencies - whether part of either
government or the private sector - are herein advised to refer to legal
counsel in order to determine the legal and lawful guidelines for the use of
any equipment promoted or sold by ISIS.
What is the difference between "hardwired" and "wireless" video equipment?
"Hardwired" refers to equipment that is directly connected via cable or wire.
For example, a hardwired videocamera sends its signal through a cable all
the way to its final destination (VCR or monitor). "Wireless" refers to
equipment that transmits its signal via radio frequencies. A wireless video
camera will be connected via a shortlead to a transmitter which sends its
signal on a radio frequency to a receiver set to receive that frequency.
Thereceiver will be connected via a short lead to the final destination (VCR
or monitor).Advantages & Disadvantages: The advantage of a "hardwired" system
is that you can usually rely on havinga strong clear signal at ! your
destination given that you are using a reasonably high quality cable and not
runningan unreasonable length. The disadvantage of a "hardwired" system is
the need to run cable between yoursource and destination. This can become
cumbersome and costly in situations where you have to run betweenwalls,
streets and buildings. It's especially difficult to do so in a covert
manner. The advantage of a "wireless" system centers on its ease of setup.
Long cable runs are eliminated allowing forquick, inexpensive and covert
installations. The disadvantage of a "wireless" system is its susceptibility
to interference problems. The video signal is no longer on a dedicated run
but rather is sharing a frequency with whatever might be on it at the same
time. This can lead to signal problems where your video quality
diminishessomewhat. However this is rare with the number of frequencies
(! channels) available to transmit on.
What kind of transmission distance can I expect?
This question is dependent on so many different factors that it is difficult to answer in a specific
fashion. Our FCC Part 15 compliance transmitters will typically transmit
1000-1500 feet line of sight and 300-400 feetindoors. However, transmission
distance can be greatly reduced depending on what you are
transmittingthrough. Metal barriers, water and human bodies can all have
serious impact on a 2.4 GHz transmitter's signal.Try to avoid these obstacles
when setting up your wireless system. Common construction materials such
aswood, cement, drywall and brick are penetrable.
Can I improve the 1000-1500 feet line of sight transmission distance?
Yes, increased range can be obtained while still remaining under Part 15
compliance. This is accomplished byincreasing the dB gain of your receiving
antenna. FCC regulations restrict you from changing an FCC Part 15approved
transmitting antenna but the receiving antenna is fair game. Higher gain
receiving antennas can increase the range by as much as 75% depending on the
model. One drawback of higher gain antennas,however, is that they are
usually more directional than lower gain antennas. This means that the
antenna must be pointed exactly right to benefit from its higher gain.
Higher output transmitters are available for export and law enforcement.
! These transmitter amplifiers can go as far as 10 miles depending on the model.
How many wireless devices can I operate at once without interference?
This depends on the frequencies of those devices. Our 2.4 GHz systems have 4
channel capabilities meaning that you can run up to 4 different video
transmissions simultaneously on 4 of our transmitters. You will need
onetransmitter for each video source and you will also need 4 receivers if
you want to watch all signals simultaneously. If you needed more channels
you would have to go to other FCC approved frequencies like inthe 900 MHz
band. Usually it is best to run 4 or less wireless video signals to avoid
complications. You mayeven have some ghosting effects when running 4 signals
at once. This is due to the very narrow band allocatedfor 2.4 GHz use. Because the 4 channels are squeezed tightly to one another there is an
occassional bleedingof one channel into the one next to it. This can be
avoided by spacing the channels apart (eg. one on Ch. 1 andone on Ch. 3).
How do I convert Battery Usage Requirements to Hours of Operation?
To calculate the time in hours, you divide the Nominal Capacity of the battery
in milliamps by the Total Current Consumption Rate of the item being run off
the battery.Example: You are running a black/white board camera that consumes
150mA off of an 800mA battery (.8Amp). Divide 800 by 150 to yield 5.33 hours
of operational power use.Note: Peak battery performance diminishes as it
reaches the end of the estimated operational cycle. To ensureuninterrupted
power performance, replace battery 15-30 minutes prior to end of cycle.
What is omni-directional versus directional?
These terms refer to the signal being sent from the transmitter antenna. An omni-directional antenna will
transmitin 360 degrees on the horizontal plane and in the neighborhood of
30-40 degrees vertically. A directionalantenna will transmit only in the
direction it is facing with approximately a 15-35 degree conical signal
dependingon the gain of the antenna. The higher gain antennas usually have a
more narrow signal pattern. Omni antennasare usually less gain and therefore
will not transmit as far as directional antennas. Their advantage is that
theirsignal is sent in all directions at once. Directional antennas are best
suited for stationary point to point applications. Omni an! tennas are best
suited for either mobile applications or those that require transmission
tomultiple receivers located in different directions from the transmitter.
I have a low light situation, what type of camera should I select?
When selecting a camera, one should always check to see what Lux rating the camera
operates on. The lower the Lux rating, the lower the amount of light is
required to capture what the camera is seeing. For example, theB/W Bullet
CCD Camera with Infrared LED's (DB520IR) has an illumination of 0.0 Lux
indicating that virtually nolight is required.
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