laser detection an jumbled reply for speed traps

[audioguru]

My city is owed millions of dollars in unpaid parking tickets. They have a staff of 100 people to deal with it. Nothing is ever done by them.

The few times my son or I have gone to court to fight a speeding ticket, the court was so busy that all disputes were dismissed.

I was caught speeding by a radar camera and went to court, "Your honor, here is the picture from the radar camera that shows many cars, one is speeding. Which one?" Case dismissed. :lol:

 

[MrMikey83]

"Your honor, here is the picture from the radar camera that shows many cars, one is speeding. Which one?" Case dismissed. :lol:

Haha, thats pretty good.

There was an episode fo the Mythbusters where they tested popular myths for jamming police radar (both laser and the older technology). They tested mylar paper (what most fish lures are covers with), LED's mounted to the front of the car (I don't see how this would work anyway). They even tested a disco ball hanging from the rearview mirror which the cop said would have been illegal anyway. They tried liscence plate covers and even a "spinning mirror of death" on top of the car. Nothing worked.
They didn't try anything as advanced as trying to block or scramble the signal electronically though.


Several years ago, didn't some group of scientists claim that they found a way to go into the future. Their proof was when they shot a laser beam into some sort of long tube and the beam exited the tube nanoseconds before it even shot the beam?
It's been awhile so i don't remember all the details and I couldn't fidn anything with the quick search I did. Any searches I made with the words "time travel" ended up talking about one of my favorite movies featuring a certain Delorean. :lol:
~Mike

 

[Dialtone]

Well, not really into the future, but what I think you are referring to was that the light, when fired into the medium, exited the medium SOONER than expected for the distance traveled. I never heard if they solved the riddle or if they really hit on something at the Quantum level that is giving the illusion of travel faster than the speed of light.
Dialtone

 

[zm50cc]

I know this is probably a very old thread, but I just wanted to add a comment. In the US, it is not illegal to jam LASER guns. The LASAR guns are run off infrared light - governed for whatever reasons by the FDA (I think because it is light). The FDA does not have rules regarding jamming LASAR.

On the otherhand, RADAR is governed by the FCC which does prohibit interference. So, the FCC has made it illegal to jam RADAR.

Plus, radar jamming is almost impractical to do in any personal vehicle due to power constraints.

Now, LASAR is able to be jammed from a car. Check out the Blinder Laser jammer or the Laser Shifter made by Escort Radar. They only work up to a certain point though. Once you get within a certain distance from the laser source, it could overpower your jamming diodes.

 

[bigkim100]

This brings to mind a episode of Mythbusters, where thay outfitted a car with every gizmo known to mankind to jam a lazer detector. They used a huge bank of modulated lasers, constatly running that did not work....at all. They even built a array of rotating mirrors. They paintd the car with a flat finish, in an attempt to absorb the laser beam, instead of reflecting it. They also blew out a load of reflective mylar, not at all practical, but uven the hundreds of reflective strips did not "jam" the laser. NOTHING that they tried confused the radar...even slightly.
One thing that was certain, the gun works in a second, giving a readout almost instantaneously after pulling the trigger. the gun also fires several frequencies at the same time, just in case 1 or 2 of the beams become corrupted.

 

[zm50cc]

i've seen several references to that myth busters. I didn't see it - but it sounds like all of their solutions was a type of "passive jamming" - nothing eletrical.

But, the jammers i refered to actually interfere electrically with the signal.

Does anyone know if there was an actual electronic jammer used in that episode?

 

[KiwiX]

Jammer circuit

I have a commercial laser jammer,a Blinder brand unit.It consists of 9 IR LEDS driven by a 4 MHz driver circuit.
This unit does work as evidenced by the confused look from several cops as I drove past them,after each had tried to get a lock on my vehicle.In one case the cop tried to ping me for the entire length of a 800m straight,he couldn't even register that I was doing the local speed limit.
I have also had it tested against a Lidar unit owned by a local Radar detector retailer.
I wanted a second unit,so I decided to back engineer the original and I came up with this circuit ( see attachments )
The mosfet will switch several LEDs in parallel at 4 MHz.In the one pictured there is 12.A hex inverter is used as a square wave oscillator.

A previous post stated that to jam Lidar the output of the jammer needs to exceed the power of the cop's Lidar.This is incorrect.It is only necessary to exceed the power level of the echo or reflection that comes back off the target.
I used information from Traffic Radar Handbook by Donald S.Sawicki to find details of traffic Lidar operation
www.copradar.com

The Unit shown is the prototype
The LEDs are driven at 80 mA via a 220 ohm resistor each

 

[zm50cc]

interesting work. your design seems to be on all the time. Does the blinder unit only activate when it detects laser first? Also, i believe the blinders have several sensors/jammers...would your unit take care of just one of those?

 

[Blueteeth]

I've never understood why people wanted to avoid speed traps unless they intend to speed and break the law. I mean, sure, sometimes the laws are pretty silly, so a little hardware hacking harms no-one, but when thousands of people a day are killed on the road because people can't drive properly...why make it easier? And why should hardware engineers help them do it?

Detectors are available, so you know where the traps are, and therefore slow down (which is why they are there) but trying to fool them is very difficult, and rightly so. Also, how are you planning on shining the laser on the traps sensor as you go by? tracking? or are you hopping to somehow get the modulation frequency, data and timing perfect with a little 555 timer? Of course, I could be missing the point here completely, but it seems to me its very complicated to do, so much hassle when all you have to do is slow down. But I guess if your 'car' (or the kid driving it) is incapable of doing under 80mph then it might be a worthwhile investment.

Blueteeth, standing proud on his moral high-ground.

 

[Nigel Goodwin]

The moral ground would be rather less shaky if the cameras were honestly sited, the police claim they are sited at accident blackspots to reduce fatalities and serious injury - and NOT to make them lots of money.

However, considering one of them is sited because of someone commiting suicide by jumping off a bridge, I fail to see how a speed camera would help prevent it?.

 

[Blueteeth]

The moral ground would be rather less shaky if the cameras were honestly sited, the police claim they are sited at accident blackspots to reduce fatalities and serious injury - and NOT to make them lots of money.

That implies that the police/government are doing it purely for money. And even if they are, its a good thing, the government redistributes the money they make, and are bound by rules to pump any 'profits' back in to the system. So, unless all speed traps are in places that aren't 'accident blackspots' I cannot agree. The term 'honestly' is completely subjective.

However, considering one of them is sited because of someone commiting suicide by jumping off a bridge, I fail to see how a speed camera would help prevent it?.

Blame the papers/public for that, if it is true. It's the only way the authorities can appease the public's demand for 'action' aginst something, even though the public isn't willing to provide a solution. And I doubt if that is the main reason why a camera was placed there. Although it wouldn't surprise me if who-ever 'decides' where these camera's go doesn't have a clue.

Anyway, this is all off-topic, so I won't post anymore in this thread. As you know, I try not to waste posts with off-topic comments, poor jokes, and pointless words all for the sake of increasing my 'number of posts'.

Blueteeth.

PS. If you wish to discuss it further, pm me.

 

[Nigel Goodwin]

Blame the papers/public for that, if it is true. It's the only way the authorities can appease the public's demand for 'action' aginst something, even though the public isn't willing to provide a solution. And I doubt if that is the main reason why a camera was placed there. Although it wouldn't surprise me if who-ever 'decides' where these camera's go doesn't have a clue.

It's a well documented case, and has even been acknowledged by the government minister concerned.

The camera was placed there because it's an 'accident black spot', because someone died there - the fact it was a suicide by jumping off a bridge seemed to be ignored?.

As you say, the people siting the cameras don't appear to have a clue what they are doing. I don't know if it's the same down your way?, but round here a number of fixed cameras have been turned round (and presumably turned off?) - I wonder if that's a response to the cameras being sited in unsuitable locations?.

 

[KiwiX]

Well in New Zealand the Police do do it for the money.They are contracted to provide "road safety" by the state accident compensation organization and the state road authority and their performance is measured by the number of tickets they write.If they don't measure up the next years funding is reduced.
There has been leaked emails from top cops telling the officers to get their quotas up before the end of the month because ticket numbers were below target.
Crime is treated as a secondary concern because it doesn't bring in revenue - the traffic cops get the best equipment.Most cops hate this situation.
Joe public is targeted on the roads,given tickets for anything 11 km/h over the limit,because they will pay their fines whereas the criminal types on the road don't.

Rant over.
Yes this unit is on continuously.This is not a problem as they are not illegal here and most cops here are not bright enough to know why their Lidar isn't working.Also they believe their own propaganda that radar detectors and jammers don't work.

 

[KiwiX]

I've never understood why people wanted to avoid speed traps unless they intend to speed and break the law. I mean, sure, sometimes the laws are pretty silly, so a little hardware hacking harms no-one, but when thousands of people a day are killed on the road because people can't drive properly...why make it easier? And why should hardware engineers help them do it?

Detectors are available, so you know where the traps are, and therefore slow down (which is why they are there) but trying to fool them is very difficult, and rightly so. Also, how are you planning on shining the laser on the traps sensor as you go by? tracking? or are you hopping to somehow get the modulation frequency, data and timing perfect with a little 555 timer? Of course, I could be missing the point here completely, but it seems to me its very complicated to do, so much hassle when all you have to do is slow down. But I guess if your 'car' (or the kid driving it) is incapable of doing under 80mph then it might be a worthwhile investment.

Blueteeth, standing proud on his moral high-ground.

The commercial unit is on all the time too.Some later designs detect the lidar and switch on the IR source,Obviously for jurisdictions where jammers are illegal.
The unit doesn't need to point at the lidar accurately,it isn't using lasers they are just IR LEDs.It forces the Lidar to try to detect it's echo in a very bright IR light source.Like trying to see a candle next a spotlight from 1000m
Detectors are fine for microwaves-I use a Valentine 1 for radar detection.
But they are not so good for lidar as it is a tight beam and your done soon after the detector warns you.Lidars take only about 3 seconds to lock on a vehicle,not instantly as someone posted.