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Speedy Surveyor

Original Poster:

249 posts

71 months

[news] 
Tuesday 21st October 2008 quote quote all
Does anyone know what sort of detection range mobile speed cameras (white vans and laser guns) have?

Brett928S2

1,504 posts

100 months

[news] 
Tuesday 21st October 2008 quote quote all
Hi smile

I "think" its 1000 metres...

SS2.

8,016 posts

123 months

[news] 
Tuesday 21st October 2008 quote quote all
Depends upon the variant used - some are approved for use at distances up to 999.9m, others less.

Speedy Surveyor

Original Poster:

249 posts

71 months

[news] 
Tuesday 21st October 2008 quote quote all
SS2. said:
Depends upon the variant used - some are approved for use at distances up to 999.9m, others less.
Ok, so when my speed detector notifies me of a possible mobile speed trap within 500 yards and I'm travelling significantly over the limit then the chances are I'll be caught (if there is one in place) even if I quickly wipe off my speed?

SS2.

8,016 posts

123 months

[news] 
Tuesday 21st October 2008 quote quote all
Speedy Surveyor said:
Ok, so when my speed detector notifies me of a possible mobile speed trap within 500 yards and I'm travelling significantly over the limit then the chances are I'll be caught (if there is one in place) even if I quickly wipe off my speed?
It takes less than 0.3s to take a measurement - if you are speeding, and if your detector warns you of a laser shot, then chances are you won't have time to react before you are pinged.
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Speedy Surveyor

Original Poster:

249 posts

71 months

[news] 
Tuesday 21st October 2008 quote quote all
SS2. said:
Speedy Surveyor said:
Ok, so when my speed detector notifies me of a possible mobile speed trap within 500 yards and I'm travelling significantly over the limit then the chances are I'll be caught (if there is one in place) even if I quickly wipe off my speed?
It takes less than 0.3s to take a measurement - if you are speeding, and if your detector warns you of a laser shot, then chances are you won't have time to react before you are pinged.
My detector uses GPS rather than a laser detector but either way I'm guessing it wouldn't make any difference....

SS2.

8,016 posts

123 months

[news] 
Tuesday 21st October 2008 quote quote all
Speedy Surveyor said:
My detector uses GPS rather than a laser detector but either way I'm guessing it wouldn't make any difference....
It would if the operator was detecting vehicles travelling from the opposite direction.. spin

Speedy Surveyor

Original Poster:

249 posts

71 months

[news] 
Tuesday 21st October 2008 quote quote all
SS2. said:
Speedy Surveyor said:
My detector uses GPS rather than a laser detector but either way I'm guessing it wouldn't make any difference....
It would if the operator was detecting vehicles travelling from the opposite direction.. spin
Ahhh good point. I suppose with built up areas a 500 yard warning would be good enough regardless of the direction of the laser due to bends in the road, buildings, traffic etc. I guess it's the long straight dual carriageway sections which are the ones I need to be more aware of. Cheers.

edinandrew

209 posts

88 months

[news] 
Tuesday 21st October 2008 quote quote all
It won't go round a bend though. The general rule is that if you're speeding and you can see it then you're too late ....... usually.

pdV6

16,439 posts

146 months

[news] 
Tuesday 21st October 2008 quote quote all
Speedy Surveyor said:
SS2. said:
Speedy Surveyor said:
Ok, so when my speed detector notifies me of a possible mobile speed trap within 500 yards and I'm travelling significantly over the limit then the chances are I'll be caught (if there is one in place) even if I quickly wipe off my speed?
It takes less than 0.3s to take a measurement - if you are speeding, and if your detector warns you of a laser shot, then chances are you won't have time to react before you are pinged.
My detector uses GPS rather than a laser detector but either way I'm guessing it wouldn't make any difference....
Then it depends on how accurate the GPS map of the scamera zones is.

Sensibly, for a mobile camera area you would expect the start and end point of the zone to be mapped plus an allowance for the range of the camera/laser. Whether this is the case or not would have to be discussed with the purveyor of your map/POI database.

For laser detectors, it's basically safe to say that if the detector goes off you've probably already been caught (unless you have some illegal counter-measures installed).

bluepolarbear

1,598 posts

131 months

[news] 
Tuesday 21st October 2008 quote quote all
Speedy Surveyor said:
Does anyone know what sort of detection range mobile speed cameras (white vans and laser guns) have?
Upto 1000m if operated by police, normally significantly less if operated by scamera due to desire to take picture and speed reading together. Of course with the latest mobile SPECS trials it becomes rather inmaterial what the range is.

bryan35

1,845 posts

126 months

[news] 
Wednesday 22nd October 2008 quote quote all
the old laws of physics come into play.

very very roughly the max distance that it's possible to read a number plate is about 50000xdiameter of the lens. (with a min pixel size of 5mm on the object viewed)

So, a 10cm lens gives an absolute maximum 50,000cm - 500m readable range.

in reality the resolution isn't near this, and the video lens isn't that big either, so perhaps 200-250 meters. Any more than this and you just can't pick out the letters and numbers.


SS2.

8,016 posts

123 months

[news] 
Wednesday 22nd October 2008 quote quote all
bryan35 said:
in reality the resolution isn't near this, and the video lens isn't that big either, so perhaps 200-250 meters. Any more than this and you just can't pick out the letters and numbers.
But, in the case of mobile units attached to a recording device, they can ping the vehicle at a distance and remain focussed on said vehicle until such time as the number plate is legible.

And, purely for interest, I believe that the LTI 20-20 is capable of 'functioning' at distances in excess of 3km.


Just_a_guide

251 posts

89 months

[news] 
Wednesday 22nd October 2008 quote quote all
SS2. said:
bryan35 said:
in reality the resolution isn't near this, and the video lens isn't that big either, so perhaps 200-250 meters. Any more than this and you just can't pick out the letters and numbers.
But, in the case of mobile units attached to a recording device, they can ping the vehicle at a distance and remain focussed on said vehicle until such time as the number plate is legible.

And, purely for interest, I believe that the LTI 20-20 is capable of 'functioning' at distances in excess of 3km.
If not more as long as you don’t need to really on it home office type approved top trump card then it limited to the type approval distance for law enforcement.

JustinP1

11,228 posts

115 months

[news] 
Wednesday 22nd October 2008 quote quote all
Just_a_guide said:
SS2. said:
bryan35 said:
in reality the resolution isn't near this, and the video lens isn't that big either, so perhaps 200-250 meters. Any more than this and you just can't pick out the letters and numbers.
But, in the case of mobile units attached to a recording device, they can ping the vehicle at a distance and remain focussed on said vehicle until such time as the number plate is legible.

And, purely for interest, I believe that the LTI 20-20 is capable of 'functioning' at distances in excess of 3km.
If not more as long as you don’t need to really on it home office type approved top trump card then it limited to the type approval distance for law enforcement.
However... we all know how much the Code of Practice is conformed to... There's a guy called Peter Ward on this forum who lost out thousands fighting his case when he was zapped over the approved distance.

The only reason why the device is only used up to 999.9m is that the display only has four digits!

Clearcoat

1,908 posts

94 months

[news] 
Wednesday 22nd October 2008 quote quote all
I have posted this before, BUT gives an idea of a distance and how clearly they can see a good distance away



pdV6

16,439 posts

146 months

[news] 
Wednesday 22nd October 2008 quote quote all
Clearcoat said:
I have posted this before, BUT gives an idea of a distance and how clearly they can see a good distance away


Did anyone respond before to note that it seems that a road sign is doing 61mph?

Just_a_guide

251 posts

89 months

[news] 
Wednesday 22nd October 2008 quote quote all
JustinP1 said:
Just_a_guide said:
SS2. said:
bryan35 said:
in reality the resolution isn't near this, and the video lens isn't that big either, so perhaps 200-250 meters. Any more than this and you just can't pick out the letters and numbers.
But, in the case of mobile units attached to a recording device, they can ping the vehicle at a distance and remain focussed on said vehicle until such time as the number plate is legible.

And, purely for interest, I believe that the LTI 20-20 is capable of 'functioning' at distances in excess of 3km.
If not more as long as you don’t need to really on it home office type approved top trump card then it limited to the type approval distance for law enforcement.
However... we all know how much the Code of Practice is conformed to... There's a guy called Peter Ward on this forum who lost out thousands fighting his case when he was zapped over the approved distance.

The only reason why the device is only used up to 999.9m is that the display only has four digits!
"he was zapped over the approved" Hows that then?


Clearcoat

1,908 posts

94 months

[news] 
Wednesday 22nd October 2008 quote quote all
pdV6 said:
Clearcoat said:
I have posted this before, BUT gives an idea of a distance and how clearly they can see a good distance away
Did anyone respond before to note that it seems that a road sign is doing 61mph?
Yes, and I confirmed that was the speed of the last zapped person and not the sign ..

SS2.

8,016 posts

123 months

[news] 
Wednesday 22nd October 2008 quote quote all
Tuscan Rat said:
Before we get excited about readings of 3km etc,
The point being made (AIUI) was that whilst the LTi 20-20 is Type Approved for use at distances of up to 999.9m (depending upon the variant), it could 'function' at distances of 3km or more.

Tuscan Rat said:
To report anyone for speeding you need to forms of evidence. This can be in many different forms from Two officers making the same opinion that the vehicle was speeding to One being the officer’s prior opinion, backed up by the laser reading.
yes Apart from motorways where, as the law stands, the same rules of corroboration do not apply.

Tuscan Rat said:
My point being can anyone judge the speed of a car at 3km away ??
No one can. But then the units are not approved for use at that distance anyway.

Tuscan Rat said:
..my rule of thumb is normally about 2 - 300 metres away depending on the road and conditions etc.
How Heineken wink. But members of the SCPs will quite happily submit sworn evidence that they are perfectly capable of discerning 35mph from 30mph at a distance of 600m+. And who do you think the magistrates are likely to believe ?

Tuscan Rat said:
Therefore, how can a member of police staff who operates the camera vans be an expert witness and say they saw a vehicle travelling at a speed they estimated to be XX, before sighting the laser to get the true speed of XX ??
That one is pending AFAIK. Until someone is willing to take a case all the way and a decision is made by a higher court, the SCPs will continue to use civilians to gather the primary evidence in speeding prosecutions.
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