Why did I get a laser warning?? (1 Viewer)

GonadsofWrath

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I was on the highway. I suddenly get a laser warning. About half a mile back, I see flashing lights and a police cruiser traveling extremely fast. I was only going 5 MPH over. As he approaches, I pull off to the side. He blows past me and takes the next exit. I get off at the same exit and I see him traveling extremely fast on a nearby highway. He obviously was on the way to an urgent call; he definitely wasn't interested in pulling anyone over for a traffic infraction at the moment. So why would my Cobra give me a laser warning? I find it hard to believe that this officer, while en route to an urgent situation miles away, would have had one hand on the wheel and another hand on the laser gun.
 

GonadsofWrath

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It was probably a false. Laser can't be used with the shooter's car moving. It's only stationary.
I'm returning the Cobra tomorrow. I only got it because I was curious as to how bad it was. I didn't expect it to be so bad as to give completely unwarranted warnings! I looked around for cops and I had Waze open and the only cop around me was the one speeding to a call somewhere. It was 3am in the morning too when this happened and I'm very familiar with the stretch of highway I was on, so I'm pretty sure there wasn't a hidden cop somewhere with a laser.

I do wonder what caused the false alarm though. Maybe it was the flashing lights? The unit claims to have 360 degree laser detection and requires a clear line of sight out the back window. Perhaps the red lights triggered the laser detector?
 
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BlueV1

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Various cars broadcast laser as part of their driver assistance systems. New Mazdas are particularly bad. Also, street mapping vehicles are spewing strong laser all over the place and can be picked up 90 degrees off axis pretty easily.
It's too bad that you couldn't tell which way the laser was coming from. That would have narrowed it down a bit. :)

Now, about laser detection in the average windshield mount unit... If I don't say this, someone else will. (It's intended as a public service to any future readers that don't already know):

The design of laser detection in most windshield detectors is very poor and if you were to get a legitimate laser signal, the LEO would already have your speed.

Knowing that you were targeted is valuable info, but in almost all cases, it's too late to change anything to avoid trouble. :)
 
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GonadsofWrath

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It is definitely a possibility that some one had laser based driver's assistance around me, but I was the only car around for about half a mile or so. I'm not going to sweat it. When I have saved up enough money, I'm going for a R3 or R7.

Also, the Cobra manual is extremely deceptive. I already knew that laser warnings are insufficient in most cases. When you get a laser warning you better start thinking of explaining to the officer what the hell you were doing going so fast. But the manual gives you a nice introduction to the basics of laser and even says that laser is not the proper name--LIDAR is. And the manual instructs you to take immediate action after getting a laser alert LOL. The only relevant immediate action is thinking of where to pull over.
 

SalmonSurprise

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There are 1000 reasons to return and upgrade your Cobra, but a laser false here and there isn’t one of them imo. I have received laser falses with every detector I have owned from everything from sunlight reflections to other vehicles. It happens.
 

compu44

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I've had that happen with Cobras before in that exact scenario. It seemed to be certain light strobes on the police cars causing it.
 

SalmonSurprise

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I've had that happen with Cobras before in that exact scenario. It seemed to be certain light strobes on the police cars causing it.
Lol for a second I thought you were serious.
 

compu44

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No jokes involved. I searched a bit further and apparently Cobra actually had a feature like this advertised on some models. It was actually looking for the Opticom/Tomar transmitter on emergency vehicles.

"Cobra's Strobe Alert will alert motorists to over 50,000 emergency vehicles equipped with strobe transmitters that activate red lights at traffic intersections in emergency high speed situations. Call your local Fire/Police department for your area coverage. " - Cobra XRS 9740, Cobra XRS9740, Cobra Detector Radar, Cobra Radar, XRS 9740
 

SalmonSurprise

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No jokes involved. I searched a bit further and apparently Cobra actually had a feature like this advertised on some models. It was actually looking for the Opticom/Tomar transmitter on emergency vehicles.

"Cobra's Strobe Alert will alert motorists to over 50,000 emergency vehicles equipped with strobe transmitters that activate red lights at traffic intersections in emergency high speed situations. Call your local Fire/Police department for your area coverage. " - Cobra XRS 9740, Cobra XRS9740, Cobra Detector Radar, Cobra Radar, XRS 9740
Yeah, I know what you’re talking about. But that will not trigger a laser alert on a Cobra. I remember a long time ago when I had a Cobra it specifically had a special tone and alert on the screen for emergency vehicle approaching that was activated by the same thing in their vehicle that activates the emergency system on the traffic signals. At least that was my experience.

When I thought you were joking I thought the “certain light stobes” on police cars causing Cobras to give laser alerts were the actual laser guns in the police cars.
 
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sdrawkcaB

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I remember a long time ago when I had a Cobra it specifically had a special tone and alert on the screen for emergency vehicle approaching
That sounds like it may have been the legacy Safety Warning System standard. Early and mid-2000's detectors supported that for many years. In addition to radar detectors, there were some automobiles and mobile GPS map units that would also detect and alert to SWS as well.

Regarding the OP's laser alert, I think that @compu44 theory is the most plausible. It could have been actual xenon strobe lights on the cruiser. Xenon strobe flashes leak huge amounts of infrared light. Flashing at a fast rate could easily trick a low quality radar detector into a LIDAR alert as it sees pulsating infrared light. The other possibility is that it was an actual dedicated IR LED strobing system, a dedicated traffic signal preemption transmitter. These are devices used by some municipalities emergency responder vehicles which allow the emergency vehicle priority right of way through the traffic lights.

You got me on a side tangent of sharing some cool information about how traffic signal preemption works...

To assist emergency responders in navigating busy intersections quickly and as safely as possible, traffic-signal preemption systems were developed. These were transmitters equipped onto emergency vehicles which would transmit a signal via pulsating infrared. The infrared light would be picked up by a sensor that was usually mounted up high, typically right near or above the actual intersection traffic lights. When these IR sensors at the intersection detected a pulsating light at the matching repetition rate, they would trigger the traffic signal preemption on the intersections controls. This would typically cause the traffic on opposing directions to be stopped, and only the traffic signal which initially detected the IR preemption pattern would become green. This allowed emergency services to safely enter the intersection and go in any direction they pleased since all other directions of traffic would be stopped.

These early preemption controls inherently trusted all preemption requests, having no logic for authenticating the identity of the device requesting traffic signal preemption. One small business created and sold a device called "The MIRT", an infrared strobe light one could mount inside their car on their front dashboard. The MIRT owner could then activate their MIRT device while waiting at an intersection in order to make their direction of traffic turn green within seconds of activation. Local and national news outlets ran news coverage of this device in existence and demonstrating it being used. This led to various changes in both technology and law. States quickly enacted laws banning owning and or operating traffic signal preemption devices without proper authorization. Traffic signal control systems - specifically traffic signal preemption transmitters and receivers were improved upon to now implement authentication and authorization into their base logic. Updated preemption systems changed to digitally encoded transmissions. In jurisdictions where traffic signal preemption systems were deployed, emergency vehicles were assigned a unique ID. This ID would then be digitally transmitted via timed infrared pulses. No two emergency vehicles had the same ID. When the IR sensors at the intersection would detect an encoded IR transmission, they would then know the ID that the emergency vehicle was announcing itself as. The system would then check its database to see if that ID was authorized to preempt the intersections traffic controls. If it was recognized and listed as permitted, then the preemption process would begin. If it was not recognized or was recognized but not authorized (such as an emergency vehicle from a different state), then the preemption request would be ignored.
 

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