Inventor wins speed camera battle
Dr Phillip Tann
Dr Tann claims his system is more accurate than mobile cameras
A scientist escaped a charge of speeding at 42mph, after claiming a device he invented showed him travelling 12mph slower.

Sunderland University lecturer Phillip Tann, 45, was told mobile speed officers recorded him speeding in a 30mph zone in the city last November.

But Dr Tann, from South Shields, had data from a satellite tracking device, showing him travelling at 29.18mph.

The Crown Prosecution Service confirmed proceedings against Dr Tann had ceased.

Dr Tann was told he had committed the offence on Sunderland's Kier Hardie Way on 27 November 2006.

He was faced with a fine and penalty points, but contested the case and elected for trial at Sunderland Magistrates' Court.

Officer retired

Dr Tann's invention is built into a mobile phone and records its location and speed on a computer database.

The design has already received government funding, with a £60,000 NStar proof of concept award.

His company, Autopoietic Systems, plans to market a consumer version of the technology later this year.

The technology lecturer believes his case could open the floodgates for other motorists accused of speeding.

He also called for better training for police officers who have to use mobile speed detection equipment.

Dr Tann said: "The mobile cameras used are not 100% accurate.

"My system can track a GPS phone within half-a-metre of where it is, whereas devices currently on the market can, at best, only track a phone within five metres."

A spokesman for the Crown Prosecution Service (CPS) said: "The officer who operated the camera has since retired.

"Without his verbal evidence, we could not prove the case to the required standard."
you guys seen this?

PistonHeads Headlines

 

Crikey!!!

 

wonder if the points and prosecutions will be over turned?

 

Mackems will do owt not to part with their wedge

 

thought this would provoke more replies

 

Personally I think its all a load of hot air. I think this is just a show of PC so that they can further prove how great the system of speed detection is. I am almost certain it will be an exercise of self gratification/justification. They just want to appear to the public that they are taking on board concerns, then it will be back to business as usual, but now with extra proof that they really are right.

 

think theres more to it than that mate the legal implications of a calibrated laser giving incorect info means a design fault or something else maybe.

 

That was proved on a documentary on TV about 4-6 months ago, but nothing has happened since then.

 

this feature is also in garmin sat nav ,
select tracks and you can view your taken route - pin point your location at a given time at a max speed .

even the rozzers get it wrong lol

 

Saw this as an article in a paper - the problem was that his "method" only recorded an average speed over a distance, which the police pointed out that could mean he was speeding when he was "lasered", but when he realised, he slammed his brakes on and by the time he stopped/slowed down his "method" only could record an average speed, not an exact speed.

Personally, I couldn't see how either party could prove it one way or another, so my money would be on the Police winning the case if this challenge came up again in the future. The legal system has a habit of not liking anything that challenges their "facts", so I won't be counting on this "method" to save me a fine or points...... just slow down instead - much safer......

 

How do you know that his method time sample ? That's what a laser gun does, it takes a number of time and distance samples and computes speed.
This method is too simple and is prone to a number of errors due to the fact that a radar relies on return signal.

On the other hand, a gps method would be using the same speed =distance/time formula. However it is not relying on return signal and it seems that his method could probably be even more advanced to have an error of up to 1/2 meter. Don't know what is the signal acquisition time for the professor, but it will probably be less than what it would have taken him to accelerate from 30 m/h to 42 m/h and back to 30 m/h. Professor has a much stronger case here !!!

 

According to Sky (yes, I know) acquisition distance for the prof's device is 41 metres. Don't know about you, but I could slow down a lot in that distance. I notice that he does not report is average speed for the 41m cell just before the one he was done in.


M

 

Are you sure? I thought it (edit: the laser gun) used the Doppler effect to calculate the speed?


Edit: Actually, turns out you're right: Howstuffworks "How does a laser speed gun work to measure a car's speed?"

 

I have just had a peek at this, to see how they are improving the positional accuracy of stand alone GPS. Seen as the device in question is a mobile phone, it is unlikely that it is using carrier phase positioning, and therefore just using normal psuedo range computation, and all the errors associated with such.....

Given that the system is quoting accuracies of < 1.5m from a pseudo range computation with no external input of differential or real time gypsy corrections, it can only be logging GPS data in proprietary format (probably Rinex) and being post processed at a later date.

You can actually do this for free by logging the data yourself and sending it here: Geoscience Australia: - Geodesy AUSPOS - Online GPS Processing Service which I have witnessed on a number of occasions.

The company I worked for was developing a gps tracking system in 97, and had a similar situation which went to court and did not have such a successful outcome, so I am surprised at this.

Laser technology is inherently flawed. Having used it every day for tracking purposes, I have seen it perform badly in rain, fog, mist and in some cases, direct sunshine.....

I don't know how laser has been successfully used for so long tbh...