Police radars - testing?

[dpex]

Does anyone know the real rules regarding the testing and certification of the radar sets used by the cops?

Who tests the units and how often?

Are the units then supplied with some form of certification? If yes then who has that? The cop, or the testing facility?

Naturally, we know two on this site who do, but I suspect they'll be slow in coming forward with the goss.

Also, does anyone know how these units are calibrated? By that I mean, can they be calibrated to cease detection at a specific distance, and is that specific distance determinable by adjusting the unit?

If yes, how and how often is this function tested?

Further, one thread here (earlier this year) suggested the radar units were capable of detecting a vehicle 'behind' the leading vehicle. Is this true or just another Star-Trek fantasy?

Does anyone know where I could obtain the specifications (performance and operation) on the radar units used in NZ?

I ask all this because I think I've been unfairly nicked. I don't mind copping a fair nick, but the various circumstances surrounding this one seemed extremely shonky; which were...

The cop was parked on the left hand side of the road, some 700 M ahead.

His car was facing away from me. He was sitting in his car at the time he claimed he detected me. Thus he could have 'seen' me only through his rear-view mirror....700 M away.

The zone into which I entered changes from 100Kph to 70 Kph.

A large NZ Post truck had been dogging my arse for the previous ten Ks. He was about 100M behind me when I entered the 70K zone, so he was still in the 100K zone.

The truck is huge compared to me and my bike. So which of the two would the radar unit have detected?

But then there's the 'where was I' when detected? Was I actually inside the 70K zone or not?

And how could a cop, sitting 700 M ahead, looking at me in his rear view mirror have determined where I was at the time of the alleged infringement?

He hit his 'Gotcha' lights within seconds of me passing the 70K sign, and at no time, from his view, could I have been between him and the sign. So how could he determine I was actually inside the zone?

That's why I asked if these dinguses can be set for a specific distance for detection.

[Blackshear]

I haven't got much info brah, but, prepare for the shitstorm and impending 'SEARCH' function telling off!
I, however, will be reading with earnest.

[bully]

i too will be interested. damb pig passed me on a double yellow line today, rules of there own.

[_Shrek_]

Further, one thread here (earlier this year) suggested the radar units were capable of detecting a vehicle 'behind' the leading vehicle. Is this true or just another Star-Trek fantasy?

The truck is huge compared to me and my bike. So which of the two would the radar unit have detected?

But then there's the 'where was I' when detected? Was I actually inside the 70K zone or not?

And how could a cop, sitting 700 M ahead, looking at me in his rear view mirror have determined where I was at the time of the alleged infringement?

He hit his 'Gotcha' lights within seconds of me passing the 70K sign, and at no time, from his view, could I have been between him and the sign. So how could he determine I was actually inside the zone?

The new radars show cop speed if they are moving, the biggest & the fastest,

he would have been sitting at the 700m mark & waited & know'n when you were in the 70k area

& i'm pretty sure the new radars can detect out to 2km

[stevedg]

if you write to the NZ Police Infringement Bureau requesting the 'operators Manual and Module', 'Maintenance record' of the device and 'certificate of accuracy' for the device they will post it to you. The Manual and Module makes interesting reading and pretty much explains how to use them to avoid 'making mistakes', although I know from personal experience they or the operator is not infalable! It's proving that they made a mistake that's the problem!

[CookMySock]

Who tests the units and how often?

hey have their own internal calibration department. The units are classified as calibrated scientific instruments, so their accuracy is not challengable in court.

Are the units then supplied with some form of certification? If yes then who has that? The cop, or the testing facility?

Yes, the unit has a certification with it.

Also, does anyone know how these units are calibrated? By that I mean, can they be calibrated to cease detection at a specific distance, and is that specific distance determinable by adjusting the unit?

The units have no concept of distance, only size of reflection. Small reflection for bikes, large one for trucks.

Further, one thread here (earlier this year) suggested the radar units were capable of detecting a vehicle 'behind' the leading vehicle. Is this true or just another Star-Trek fantasy?

They can detect the largest target, and the fastest target.

The cop was parked on the left hand side of the road, some 700 M ahead.

His car was facing away from me. He was sitting in his car at the time he claimed he detected me. Thus he could have 'seen' me only through his rear-view mirror....700 M away.

Yes the microwave unit will detect you at that distance.

A large NZ Post truck had been dogging my arse for the previous ten Ks. He was about 100M behind me when I entered the 70K zone, so he was still in the 100K zone.

The truck is huge compared to me and my bike. So which of the two would the radar unit have detected?

This is the good bit. You have a logical case here. The microwave unit cannot tell him which target is which. It will register the strongest reflection, and also the fastest target.

If it registered the truck as the primary target, then it cannot detect you unless you are going faster than the truck. This is unlikely, since you were closer to the 70k zone than he.

If it registered YOU as the primary target, then it stands to reason that there MUST be a faster secondary target registered, since he was outside the 70k area, and you were inside it.

It is impossible to tell who was the primary target, since you are closer but much smaller, and he further away, but provided a much much larger reflective surface to the transmitted microwave signal. In this case, it is perfectly feasible for the microwave unit to actually repeatedly exchange lock between both you and the truck.

I would be asking the officer in court, "was I the primary target or the secondary target?" If he said "primary", I would ask how he could tell the difference between a larger further away object, and a smaller closer one. You will get a blank stare from him, and a raised eyebrow from the judge. If he said "seconday", then I would be asking him how it was possible you were travelling faster than the truck following you, and how would that be logical since you were inside the 70k limit and he outside it.

Either way, pretty much he is screwed IMO.

And how could a cop, sitting 700 M ahead, looking at me in his rear view mirror have determined where I was at the time of the alleged infringement?

They do it for a living.

He hit his 'Gotcha' lights within seconds of me passing the 70K sign, and at no time, from his view, could I have been between him and the sign. So how could he determine I was actually inside the zone?

That gives him away too. That suggests he put little or no thought into the nick.

That's why I asked if these dinguses can be set for a specific distance for detection.

No they cant. They are doppler units only. They don't have any concept of distance.

All IMO, AIUI, YMMV.

Steve

[gatch]

i too will be interested. damb pig passed me on a double yellow line today, rules of there own.

He could have been going somewhere important ?

Interesting though, I heard a while back that when there is 2 vehicles that are really close together you can't without some doubt, distinguish between the 2 vehicles with the radar..

Maybe I didn't quite get the full details ?

[marty]

DB's got it in one. his advice and knowledge of the workings and limitations of the Stalker DSR is pretty much bang on.

[bully]

what interests me is can he get done if the cop car wasnt facing toward him but both going the same direction, alltho the cop was still. im not sure he can unless he had a handheld laser facing out the rear window?
db??

[MaxB]

Agree with the SEARCH comments.

Most radar units in this country are supplied by Stalker

http://www.stalkerradar.com/

AFAIK the calibrations are carried out by ESR, a crown research institute. Police are issued a set of operating guidlines and are trained in the use of the units. Units are stickered with the date of calibration and the expiry. The particular details are not available to the general public. You can get disclosed information if you are defending a charge.

The essential problem you have is that to win in court you have to have documentary evidence that the unit was inappropratley operated or the officer made a mistake. For that you will need witnesses that can be trusted. Also expert witnesses cost $200/hr, so for that you will need to be pretty sure of your position or have deep pockets.

If you don't have witnesses prepared to go to the bitter end then it is probably better to wear the ticket and move on.

If it comes down to the cops word versus yours, the court will tend to believe the cop.

[bully]

He could have been going somewhere important ?...

without making a issue, he didnt have any lights on, shouldnt he if it was that important? isnt that what they are for? if he doesnt put lights on isnt he just another road user, passing on a double yellow is dangerous no matter who you are. it cost me 30 points and $130. hence, rules of there own. correct me if im wrong.

[rebel]

How fast did you/the truck get done for?

[jimbo600]

Also as per their general instructions they're not to issue infringements within 200m of a speed change.

[Defiant]

Okay just a fast reply to this one, Cops do have to fill out a log book for equipment operation check etc this includes the filling out of the certification log book prior to using the unit every time they start the day or take over from a previous shift. You have the right to be shown the speed and these log books before they can issue the ticket. They do have guidelines of operation that i can tell you for sure that some do not do consistantly. If you get booked ask to see the vehicle log book and see the speed on the unit.

Look at it this way, would you pay a painter for a job on your bike that wasnt painted properly? Nope cause the jobs not done right. Same thing, they have a job to do BUT they also have proceedures to do it right. I have gotten off plently tickets cause the cop just thought he'd fill it out later. But then i have also asked and been shown the correct logs and cert, I happily paid the ticket.

BEAR IN MIND THIS DOESNT APPLY TO THE HAND HELD LASER> your screwed in that case.


(Yep and i do expect to get flack from this post....)

[MarkH]

He could have been going somewhere important ?

Maybe he just heard on his police radio that there was a good special going at the donut shop?

Interesting though, I heard a while back that when there is 2 vehicles that are really close together you can't without some doubt, distinguish between the 2 vehicles with the radar..

That would be true with the standard radar, but watch out for cops with the laser guns - they can target a specific vehicle and get a speed reading.

Also watch out for the fixed camera sites, they can tell which lane the speeding car is in, so if you go over the strips in the road side by side with another car and you are going faster, they can send YOU the ticket. This happened to me once, I saw the flash, but there was a car beside mine, I thought they wouldn't know which one was going faster, that was how I learnt that the radar based cameras can't tell, but the fixed site ones can. Of course if I had been on a bike then they would only have a picture of the front of the bike and no number plate.