tracking police gps - Page 2

Altimat · 02-21-2004, 12:35 PM

http://www.radartest.com/article.asp?articleID=8000

Altimat · 02-21-2004, 12:51 PM

I searched around and the BCT-8 seems to be the comparable current unit. The BCT-12 is discontinued.

jjh221 · 02-21-2004, 06:55 PM

can be done much like n e thing else is possible. would have to spend much money and time. as well as know more than what you can search for off the internet. so if i was you i would just become a police man much easier. or become someone they buy from. good luck and remember they are our friends perhaps we can only help them see as well as us see. to much of a good thing can often turn bad. some where in the middle....

Gunmaster · 02-21-2004, 09:38 PM

bct-12 is outdated and the bct-8 isnt anything special.

Alot of cops are switching to digital here are two units uniden makes
BC796D & BC296D

Radio Shack sells one Pro-96

Gunmaster · 02-21-2004, 09:41 PM

My local PD/highway patrol/SD uses AVL to track officers. It uses either uhf/vhf/800mhz radio to send the position back to dispatch.

aleromaster · 02-21-2004, 10:22 PM

alot of departments are switching to trunking radios which alows them to transmit something like 7 differant channels over one frequency

BigRedBee · 02-21-2004, 10:45 PM

There is a fairly common way to track vehicles. Take the output of the GPS, create a packet using a TinyTrack (from Byonics) or something similar, transmit it over a ham radio frequency, and it's instantly available for all to see on the web. like this:

http://www.findu.com/cgi-bin/find.cgi?call=k7rkt-1

divideoverflow · 03-24-2004, 05:35 PM

The most likely scenario (in the US anyway) is the use of Motorola MDT or RD/LAP data transmission protocol. Many police departments use mobile data terminals to send and receive dispatches and other data that would tie up the voice channels. Adding periodic GPS coordinate updates to this data stream is pretty simple if they're already have a deployed data network.

MDT (aka MDC4800) protocol is relatively easy to decode with a scanner and soundcard input. This was a blast 5 years ago, but now just about everyone is switching to the higher speed RD/LAP protocol which runs at 19,200bps. Because it's encoding method is more complex (4 levels vs 2) it hasn't (to my knowledge) been decoded yet.

Listen to 855.8375 for data. This is the ARDIS/Motient national frequency that many police/fire/ambulance/UPS/taxis have used in the past for their mobile data terminals. Your PD *might* be using this network and they *might* still be at 4800bps, in which case you *might* be able to decode the data stream.

Obviously even if you got as far as obtaining an ASCII data stream from an MDT channel you'd still have hurdles left to jump to get a map with little red dots all over town representing police cars.

Stop speeding and you won't have to worry about it. <grin>

-- divideoverflow

ElKeeed · 10-19-2005, 07:36 AM

In the uk not only are they digitally encrypted but on channels that are not available to the public so a scanner is pretty useless nowadays.

zPilott · 10-27-2005, 10:25 AM

With some creative soldering you can get a scanner to work in ranges it wasn't intended to.

Actually reading the data might not be necessary, if you could just locate the transmitter.