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Interesting topic i think...


Was in my cousins car last night, and we passed a speed camera van (not speeding may i add), when we passed it both windows and the side window was closed, so we were thinking it was just getting ready to start, then when we were coming back about half an hour later, the back and side windows were still closed.



Usually the ones in our area always open the windows if they are speed trapping, not sure if its a new thing that they can catch you with the windows closed? Because i can't see them sitting for only 20-25 minutes at a time? Anyone know if they must display the camera or can they do it through the windows?
 

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Not sure about the windows but I believe they have to display a sign so far up the road to worn of the camera being in action.
 

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i-Vtec
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It was probably parked with no one inside, just using it as a deterrent most likely. There are a few Camera sites around me and there are certainly fixed Camera signs within a couple of hundred metres of where they sit so may be some truth in that though. Bit like the Bus lane one near my work, the sign is about 100m before it and it still catches hundreds of people a month. You've gotta love Motorists, LoL.
 

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We had the same thing up here on the A70.
The van was parked up in a lay-by, no temporary sign displayed and all windows closed.

They were definitely active though as we stopped at a services on our way back and they were there, so asked them how they got on!
 

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Ex-Pat Geordie!
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Always one lurking on the A71 between Irvine and Kilmarnock. As far as I'm aware the windows are normally open and there is definitely no warning signs to let you know of their presence.
 

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I took this video 8 years ago (and Fred Overton is not my real name LOL)
My son uses my camera from passenger seat, we're in my Accord, the detector is a Snooper 4Zero which I still have in the Accord.

Last time it went off was a year ago when I was doing 80 on the A1 and a BMW mini overtook me. I then spotted a van on a bridge about a few hundred metres ahead, slowed down to 75, then the detector went off (so the operator must have "gunned" the BMW mini and the detector detected the scatter from the laser). I didn't get a NIP, but I bet the other driver did.

So I know that the Snooper definitely successfully detects LTI 20/20

Question is, what is that fixed LTI 20/20 in the video, are NIPs produced from it ?
 

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A laser speed gun of any variety records your speed in less than 1/3 of a second and can 'get' you at 999m (LTI 20/20), so by the time the detector detects the laser, it's too late. Laser detectors are a waste on money. Radar detectors work though as do GPS based databases such as the PGPSW one.

The camera in the video was not an LTI 20/20. The LTI 20/20 is a hand held device pictired HERE

Either way, and whatever the camera was (I don't think it was a speed camera as they are painted yellow) your snooper (or whatever) only detected it when you were under it. Time enough to slow down if you were speeding? I don't think so.
 

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As with all variants of the original "road angel", the Snooper 4Zero also has a database and warns you of locations in the database (but I haven't updated it since I bought it). For me, the LTI 20/20 detector is an additional bonus, because you get to know where they are being used even when you haven't updated the database. The reason you find out, is because if there is a speeding car, then there is laser scatter when the operator triggers the laser, and the detector lets you know when it has detected the encoded pulses.

Yes I do know how they work, I know what the hand-held and van lasers look like, but that's not the question.

The question is, what is that fixed laser camera for, why is it triggering the LTI 20/20 detector if it's not an LTI 20/20. If you don't know, instead of "doing a Boris" and skirting the question, say "I don't know, I haven't seen or heard of one before".

Note that there are also other fixed systems in various locations in Coventry that also trigger the LTI 20/20 detector. In the past I've seen police cars parked up near this particular laser/camera when it first went up, but not any more because they're all out attending domestic incidents (as a traffic cop told me himself, and he didn't know about those fixed laser/cameras, neither did a van operator who I spoke to when he was eating his lunch in a Morrisons car park).
 

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Is it actually detecting an LTI 20/20? Or is it just responding to a laser beam? That housing does not look big enough for an LTI 20/20 and even if it is, what's triggering it?

But as you seem to know everything there is to know about cameras, so why ask and then be rude about my answer which was factually correct? Wish I hadn't bothered now.

I don't know. Happy now?
 

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I wasn't being rude, I was making a fair comment that you didn't answer the question, and instead went off on a tangent about the value of a laser detector [smilie=smack.gif]

Before I bought that Snooper 4Zero I did have a cheap and rather old Road Angel, which I've still got somewhere. I can't remember why I wanted to upgrade to something else, there was a specific reason, but I can't remember what that was and I don't keep a diary either, so I'll never know why I felt the need for a database device with LTI 20-20 and radar detection (it also detects radar).

Anyway, before looking for something, I found and downloaded a very good spec of the laser that's in the LTI 20-20, but I can't find that reference either now. IIRC it's something like 40 pulses in 0.33 seconds, and I also think it said that each pulse is encoded (a laser pulse is like any RF pulse and can theoretically be encoded, although I'm not convinced it's that easy on a laser pulse, and I can't find that description again). Either way, each pulse measures distance, and there has to be a certain number of returned pulses arriving back in the correct sequence, otherwise the burst is flagged as "error". If there is no error in the received return pulses, next, the speed is calculated from the change in distance of each pulse (if the object is moving there has to be a change in distance between any two sequential distance measurements). Speaking as a very knowledgeable RF engineer, as with any RF, there will be scatter from a laser pulse i.e. the pulse does not simply hit the object and return, it "blooms" out and has enough energy to be "seen" from the LTI 20-20 that emitted the pulse, as well as over a wide area (depending on the amount of "bloom").

What I also remember is that the laser is infra-red frequency. So it is possible that the Snooper responds to any infra-red beam, but, that installation is a bit over the top (with a separate security CCTV on top), and pointing up the road, to be .... well, what ??

Also, there was an identical one on the A46 southbound just after the A428, just on the LHS on the exit from the roundabout. The speed limit on the entry into the roundabout is 40, and was 60 on the dual-carriageway before and after the roundabout, and it was easy to carry 60 into the roundabout by cutting across. I can't see why someone would have gone to a lot of trouble to erect that device in that position, other that as a speed detector. i wouldn't have known that was there either, had it not been for my Snooper, and AFAIK these don't appear in any database "road angel" system.

Further along on the A46 southbound at the A45 section, there was a Gatso pointing downhill, and another Gatso in the opposite direction in a different place. Both were in the central reservation. But, the Gatso on the southbound was eventually removed, and then much much later, one of these appeared in the central reservation in a similar position. However, all of that roadway and intersection with the A45 has been totally redesigned, and all speed cameras have gone. The one on the A46/A428 roundabout also disappeared.

The one on the A512 is still there, although my Snooper didn't alert to it last time I went by.

My assumption was that these were some kind of trial device, but whether it was a trial speed detector or something else, is a mystery. Possibly they were measuring vehicle speeds for stats, but again, it's a lot of money to erect a permanent rig like that just for stats.
 

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I wasn't being rude, I was making a fair comment that you didn't answer the question, and instead went off on a tangent about the value of a laser detector [smilie=smack.gif]
Fair enough. Then I apologise for the comment.
IIRC it's something like 40 pulses in 0.33 seconds,
That is my understanding as well
and I also think it said that each pulse is encoded (a laser pulse is like any RF pulse and can theoretically be encoded, although I'm not convinced it's that easy on a laser pulse,
It's obviously easy (although I don't know how) as that's how fibre optic communications work. One light/laser beam has enormous data carrying bandwidth
Either way, each pulse measures distance, and there has to be a certain number of returned pulses arriving back in the correct sequence, otherwise the burst is flagged as "error".
I suspect it's the modulation characteristic that is measured. The laser jammers do not replicate the correct modulation, so the LTI 20/20 can easily detect that it is being jammed.
What I also remember is that the laser is infra-red frequency. So it is possible that the Snooper responds to any infra-red beam,
That would be my guess as well. Early detectors used to go off when reacting to shop door opening systems. Again, my guess is that the snooper just categorises any received laser light as an LTI 20/20, unless it does detect the modulation characteristics of the speed gun
My assumption was that these were some kind of trial device, but whether it was a trial speed detector or something else, is a mystery. Possibly they were measuring vehicle speeds for stats, but again, it's a lot of money to erect a permanent rig like that just for stats.
That would be my best guess as well. All 'we' need now is for someone to tell 'us' what they REALLY are.
 
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