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PostPosted: Wed Oct 03, 2007 07:35 
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This morning I was flashed by a camera which was setup to catch people on one side of the road when I was going the other direction. (I was over the speed limit).
The camera looks like the standard Gatso rear facing style camera and there are no graduation lines painted on the side of the road I was on.

Should I be worried?

In essence it took a forward facing picture of me, good thing I was not looking at the camera I could have been blinded by the flash as it was still dark. Has anyone heard of any cases of this happening.

Many thanks for any good advice in advance.


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PostPosted: Wed Oct 03, 2007 08:10 
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hsf68 wrote:
Should I be worried?

No. Some Gatsos do that. It's just to scare you and no photograph of you will have been taken. And apart from anything else Gatsos are not type approved for that direction.

hsf68 wrote:
In essence it took a forward facing picture of me, good thing I was not looking at the camera I could have been blinded by the flash as it was still dark.

Well, now you know (if you didn't before) that speed cameras have nothing to do with safety.

I wouldn't admit to exceeding the speed limit on a public forum BTW. Every driver does it, yes, but it's still technically an offence.

You won't get a ticket, so relax.

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PostPosted: Thu Oct 04, 2007 03:22 
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Hi! First post on the forums, but hopefully it will be useful.

Gatso cameras calculate the speed you are doing by the doppler effect - the difference in frequency between the radar signal sent and the one received allows the software in the camera to determine how fast you are going.
Speed and velocity, however, are very different - Gatsos are only calibrated in the direction of travel. If you are coming towards one, they are NOT calibrated for this.
The software in the camera does a 'simple' calculation and determines the difference in signal speed, however it does not distinguish between oncoming traffic or cars travelling away from it.

Think about it this way, if the signal is sent at a frequency of, say, 100Hz, then that is the reference the camera has. A speed going away from the camera could possibly be 50Hz - the signal has a lower frequency on the return. This would indicate a difference of -50Hz.
The same speed in the opposite direction would give a difference of +50Hz. To you and I the + and - are very significant, however the camera doesn't take this into account, and snaps the pictures. More often than not the second one is of little use anyway as you are outside the range of the camera lens, but even if you are captured on two images the photographs should be discarded by a human reviewer.

I have set Gatsos off unintentionally in the same manner, and have not been prosectued.
Just be aware of the difference concerning Truvelo cameras - these are forward facing and are DESIGNED to capture you as you are oncoming. You don't want to be setting one of those off! (Unless you don't have a numberplate on the front, that is...)


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PostPosted: Thu Oct 04, 2007 14:34 
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Syx wrote:
Hi! First post on the forums

:welcome:

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PostPosted: Fri Oct 05, 2007 03:53 
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Syx wrote:
Speed and velocity, however, are very different - Gatsos are only calibrated in the direction of travel. If you are coming towards one, they are NOT calibrated for this.
The software in the camera does a 'simple' calculation and determines the difference in signal speed, however it does not distinguish between oncoming traffic or cars travelling away from it.

Hi... ;)

I don't think that is true. From the photos I have seen of the Gatso control box there is a switch which can select approaching, receding or both. I believe they are only legally (UK law) allowed to operate in receding mode. Also the photos from the camera seem to have an "R" printed on them.

There is also the Gatso dummy unit, which does not appear to have this switch so would fire the flash for either direction.

So I believe it's a legal thing not an operational thing. I don't think any fixed speed cameras are allowed to operate in receding and approaching mode at the same time. The Truvelo Combi Smc can do both, and apparently it can do the secondary check in two different ways. :roll:

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PostPosted: Sun Oct 07, 2007 11:23 
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I've just been flashed twice by a gatso which I suspect was set off by the oncoming traffic -- I was definitely not speeding; the cruise control was set to thirty and when I looked at the speedo after the flashes, it's on exactly the thirty mark. Now, from having passed those signs that display your speed with it like that, they say 27 or 28.

But the MR2 coming the other way was definitely shifting and could well have been doing maybe 40-45.

How are the police going to know from the photograph it wasn't me? I wasn't on the graduation lines by the second flash, so they're not going to be able to count them.

Should I be expecting to have have an argument about this?

And what do I do if they try and pin the reading from the other car on me?


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PostPosted: Sun Oct 07, 2007 12:06 
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kll wrote:
How are the police going to know from the photograph it wasn't me? I wasn't on the graduation lines by the second flash, so they're not going to be able to count them.

Two photos are taken to confirm the offender’s speed with use of the graduation marks; this corroboration is necessary for prosecution due to the rather flaky nature of speed radar sensors. Your speed cannot be confirmed if your car was not over the marks in either photo.

kll wrote:
And what do I do if they try and pin the reading from the other car on me?

Demand both corroboration photos, the distance between the graduation marks and the inter-flash interval.

I doubt it will come to that judging from your description, so don't worry about it :cool: If it does you know where to find us :)

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 Post subject: Update
PostPosted: Tue Oct 30, 2007 19:14 
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No NIP. Just several weeks worrying.

I don't think it should be the job of the police to cause concern and stress to those who obey the law... so - how do I complain about the camera causing an honest, law abiding driver extra worry?


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PostPosted: Tue Oct 30, 2007 20:15 
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IPCC?

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 Post subject: Re: Update
PostPosted: Tue Oct 30, 2007 21:38 
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kll wrote:
No NIP. Just several weeks worrying.

I don't think it should be the job of the police to cause concern and stress to those who obey the law... so - how do I complain about the camera causing an honest, law abiding driver extra worry?



Time I got flashed in my face by a Gatso - I phoned up police HQ and complained that a Gatso was operating out of type approval, and that I was almost blinded and had to stop. Minutes later I got call from police to say tech was on way to camera(very yes sir /no sir ) .So my 2p worth - phone in a report ---gets them worried

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PostPosted: Tue Oct 30, 2007 21:59 
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The Unsafety partnerships have done no work on the possibilities of these damn GATSO units causing problems with the eyesight of people who are flashed by them.

My wife suffers from severe photosensitivity (she has to have photochromatic glasses) and when we were walking past a GATSO it flashed a car and she was blinded for several minutes afterwards.

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