Re: [TSCM-L] {1648} Re: Infrared transmitters

From: List Subscriber <yahoo..._at_hoobie.net>
Date: Thu, 24 May 2007 20:24:10 +0100

Standard Irda infra red units runs up to 4Mbit/sec which would come in around 1Mb of data every 3 seconds (allowing for some screw ups.)

If the device were storing the voice as say 16kbps MP3 (giving around 16khz audio bandwidth) then each MB of data would give you around 10 minutes of record time, obviously if it's a VOX unit then that could be a days worth of recording...

So assuming those IR components and the MP3 encoding scheme (all off-the shelf components); with a clean connection you could download around 10 minutes of recorded material in around 3-4 seconds.

Probably only over a small distance though, maybe max of 3 meters or so, much further than that and the throughput would drop right back.

regards

the Subscriber

James Greenwold wrote:

Part of my procedure is to take a walk aroud the facility and look for IR with Gen 3 night vision.  IR comes across like a flashlight and is easy to see.

If there was a recording (audio) from a vehicle for a day or even a few hours, how long would it take to download the data using light?  It would seem that you might have to wait  for stalled traffic.
--

James Greenwold
Bureau Of Technical Services
715-726-1400

b..._at_tacticalsurveillance.com


From: "JPapaleo" <JP..._at_nyc.rr.com>

Reply-To: TSCM-..._at_googlegroups.com
Date: Wed, 23 May 2007 15:10:47 -0500
To: <TSC..._at_googlegroups.com>
Subject: [TSCM-L] {1645} Re: Infrared transmitters

I found a digital audio recorder that was placed in the rear taillight assembly of a vehicle in which the output of the recorder was sent to an IR transmitter, also in the assembly, allowing the recorder to be downloaded via the IR link. The device help four hours of talk and could download in under a minute. Sp all you had to do was pull up behind the vehicle with the device at a stop light and you would have your remote audio with no RF involved at all. We can talk more off-line unless someone else is interested.

john

----- Original Message -----
From: don gibson <mailto:linkinves..._at_googlemail.com>  
To: TSCM-..._at_googlegroups.com
Sent: Saturday, May 19, 2007 6:51 AM
Subject: [TSCM-L] {1615} Infrared transmitters

Have any members found Infrared transmitters used for spying whilst performing a sweep ?

Received on Sat Mar 02 2024 - 00:57:28 CST