VASCAR Speeding Challenged

[buzby]

It appears that the previously reliable speed enforcement device fitted to police cards is under the spotlight, due to the arrivial of the very high frequency 'Airwave' police radio system, which is claimed may have induced errors into the readings obtained.

 

Currently, Scottish police forces have been advised to use other methods of speed enforcement, and for anyone who had been charged and due to court on VASCAR evidence to tender a not guilty plea until the accuracy claims can be established.

 

The full story is here;

Exclusive: Thousands could be spared speeding fines - The Daily Record

[patdavies]

Be aware people that this only applies to Scotland - as evidential requirements differ under Scottish law.

[ecobabe]

bbc are now saying that the Acpos has reversed its decision as home office scientists have confirmed that they are relieable:( so these devices are being used again

[buzby]

The whole point of VASCAR, was that is was a physical measure - no beams, just a calibrated police car speed. Therefore for ACPOS to first state that 2GHz transmations 'could' affect readings, only to be told by the Home Office that it doesn't somehow beggars belief.

 

I would be more inclined to believe that Airwave could randomise readings of non-physical speed devices, so perhaps this sotry is simply the thin end of the wedge....

[dx100uk]

2GHz?

airwave runs on 380-400Mhz band, p'haps why its been found out to be utter...........

 

but yes my thoughts too.

 

its such a simple system & has been quite happily working with a far worse radio system upto now [old high power AM] that the low power of airwave with its change of mode of transmission to digital PSK, and that will be very clean.

 

dx

[buzby]

Airwave? Last time I looked it was using 2.3Ghz - do you not remember the carry on with police worrying the would be made infertile by having the transcievers on their person? It was a spin off from 3G, with fast data and real time imaging too.

 

But regarding the Vascar thing - it's the lowest tech speed trap available, see VASCAR - Visual Average Speed Computer And Recorder – Police Radar Guns so I've no idea why this became an issue!

[dx100uk]

no it uses 380-400MHz band, 10kHz per channels, never ever was anything to do GHz .

the bumph about harming humans was to do with the alleged data bursts speed which is claimed to of been near 17.6Hz.

the only bit at 2.3GHz is the new heli tele downlinks they use.

 

nuff said..

 

oh and it is H not h after Mr Hertz himself.

 

dx

[buzby]

You're absolutely right! I was indeed tied up with the BTS links because that's the side I spent most time with... the fertility issue was based on the TETRA 'pulse' and from what I remember they never actually satisfied the unions on this one.

 

Back at the Scottish forces, public opinion is now back at the level it was before, as the advice from the 'Home' office kinda gave the game away when saying that providing forces use VASCAR to their guidelines, there isn't a problem. Now, cynics that we are - this advice has not (as yet) been made public. If the instructions were that when operating VASCAR no radio transmission were to be initiated this begs the question (1) Supposing they did actually forget and make a call, or better still (2) a system generated TX ping sent a databurst without any action from the car - what safeguards are there? (None, presumably?).

 

This isn't going to go away. Oh, and as for the capitalisation of Mr H, it wasn't a slight, I seldom capitalise names, and in any event, I had thought Megacycles was far funkier.....

[dx100uk]

sadly no chance.

the VASCAR system was soak tested during the latter days of the storno's, but most traffic units it was fiited to had the cleartone dualbanders.

 

the case is triple screened, and decoupled, and the timing circuit is enclosed in metal box and the trip buttons are opto isolator connected.

 

sadly extremely bullet proof to RF.

 

but then again they would have had to of been, as the stornos were notorious at producing sproggies, worst radios they ever ran.

liked the cleartones, but the T/T module was a nightmare.

they were forever blowing the squelch threshold transistor and causing the unit to deadkey on AM.

 

nuff said

 

ex met radio eng.

 

dx