Scanners and vehicle tracking devices
Dom J
VR 500) to pick up the signal from a vehicle tracking device (Datatrac or
similar). If so would the scanner have to be up close to the vehicle?.
Secondly, would your employer have to tell you if a tracking device had
been fitted to your van or can they just fit it without you knowing?.
Dom J
Peter Hawkes
"Dom J" <Domi...@btopenworld.com> wrote in message
news:b01u7p$p41$1...@sparta.btinternet.com...
Nigel Worsley
> VR 500) to pick up the signal from a vehicle tracking device (Datatrac or
> similar).
Yes, but only if you already know which frequency it is using.
> If so would the scanner have to be up close to the vehicle?.
No, it could be received miles away, but then you could not be sure which vehicle
it was coming from.
The details of a typical system of this sort can be found here:
http://www.siemens.at/datatrak/home/content03/products/cont10.htm
The first problem is finding the frequency. Each transmission is only 25mS long, so a
frequency counter with an automatic hold facility would be required. Then the slot has
to be known so that packets from other vehicles can be filtered out. This can only be
obtained by listening to the base station ( which transmits the slot timing information )
as well as the tracking device.
> Secondly, would your employer have to tell you if a tracking device had
> been fitted to your van or can they just fit it without you knowing?.
They can probably do what they like, until there is a test case under the recent privacy laws.
and "Peter Hawkes" <pe...@hawkesp.freeserve.co.uk> wrote:
> And can they be blocked !
Yes, a very low power transmitter in the vehicle could jam the signal from the base station. The
tracking device cannot transmit if it doesn't know where its time slot is.
Nigel Worsley
Dave Liquorice
> VR 500) to pick up the signal from a vehicle tracking device
> (Datatrac or similar). If so would the scanner have to be up close
> to the vehicle?.
Due to your second question I suspect your talking about the systems
where control knows where each of their fleet is by data sent from
each mobile, rather than the anti-theft tracking devices.
The vehicles have GPS receivers so they "know" where they are and I
would expect them to use Paknet or similar to transmit that and other
information back to base. These transmitters must have a reasonable
amount of power, say a watt or more. Try digging about on the web I
expect you'll find plenty of information.
> Secondly, would your employer have to tell you if a tracking device
> had been fitted to your van or can they just fit it without you
> knowing?.
The GPS aerial might be a bit of a give away. If it's their van
supplied and maintained by them for you to perform your duties for
them. I suspect they can fit a tracking device to their property
without telling you, though I guess you could argue that if they don't
tell you it's an infringement of your human rights. Of course if your
only doing what you should be doing I can't see a problem. If they
allow you to use the vehicle for private use I think they would be
wise to a)tell you and b)fit an "off" switch.
--
Cheers new...@howhill.com
Dave. Remove "spam" for valid email.
Dom J
"Nigel Worsley" <ni...@nospam.dsl.pipex.com> wrote in message
news:3e255d52$0$224$cc9e...@news.dial.pipex.com...
Thanks chaps,
thats answered my questions, time to dig the freq
counter out!!.
Dom J