Question on Laser scatter

[TheBenzMan]

All,

Had a Laser encounter on I 57 today. LEO was hiding under 167 st SB and "shooting" at traffic once they passed. The odd thing is that about 100 feet before passing the LEO, I received a LASER alert from my 8500 X50. Once passed I could see the LEO clearly shooting at traffic once traffic passed. Could have the X50 picked up a scatter ahead of me?

Thanks!

[v1user]

You probably picked of scatter in advanced. Was the LEO hidden and shooting at the rear of cars?

[TheBenzMan]

Hiding under a bridge on the right shoulder, but in plain view if you were in the right lane. Also, yes shooting at the back of cars.

I don't understand the scatter effect that well. I thought a laser detector was picking up both frequency and pulses. Does scatter still have "pulses"?

Thanks!

[Nuke]

Laser is typically a very tight beam and I thought scatter was not usual as it is with radar. I've had quite a few laser alerts on my STI and I attribute them to running VEIL and laser cover on the license plate. My theory is that the LEO has difficulty getting a good reflection off my plate and lights and ends up hunting for a good reflection. My RD is mounted low to assist picking up laser.

I've had a lot of laser hits on the entire length of I-57 thru Illinois over the past 1 1/2 years.

[target]

I thought laser was a coherent beam... How does it scatter unless it hits a lens? I've asked on another thread about how laser is actually used. I thought police officers only used radar? My detector has the LaserEye that's used for measuring how far the radar gun is from the vehicle.

[asianfire]

I thought laser was a coherent beam... How does it scatter unless it hits a lens? I've asked on another thread about how laser is actually used. I thought police officers only used radar? My detector has the LaserEye that's used for measuring how far the radar gun is from the vehicle.

HUH? Never heard that..."LaserEye that's used for measuring how far the radar gun is from the vehicle". More likely, it is for picking up laser when you get hit with it. What type of RD do you have?

[kpatz]

I thought laser was a coherent beam... How does it scatter unless it hits a lens? I've asked on another thread about how laser is actually used. I thought police officers only used radar? My detector has the LaserEye that's used for measuring how far the radar gun is from the vehicle.

It can scatter when it hits glass or be reflected when it hits other objects.

If a LEO shoots the front of a car in front of you, and there's enough distance so that the beam has spread some, some of the beam may hit the hood of the car or the windshield and be scattered/reflected rearward to hit your detector. Also, most of the time the LEO is using the gun handheld so the gun will naturally not be held perfectly still, which will cause the beam to move around especially at longer distances (take a camera and set it to maximum zoom and try to aim it handheld at a distant object to see what I mean).

If a LEO shoots a car in the rear that's in front of you, part of the beam may be reflected off the back of the car (esp. the rear plate and taillights) such that your RD can pick it up.

Both of these instances are rare however and you certainly can't count on it to save you from tickets. The V1 is the most sensitive dashmount RD to laser and gives you a better chance of picking up scatter but even then you can't rely on it.

I don't understand the scatter effect that well. I thought a laser detector was picking up both frequency and pulses. Does scatter still have "pulses"?

Take a flashlight or a laser pointer and aim it so that you can see the beam reflected off a wall or something (the "scatter"). Now pulse the flashlight or pointer on and off. Does the reflected beam pulse as well? There's your answer.

HUH? Never heard that..."LaserEye that's used for measuring how far the radar gun is from the vehicle". More likely, it is for picking up laser when you get hit with it. What type of RD do you have?

Sounds like a Cobra. They call their laser sensor a "LaserEye".

[TheBenzMan]

Kpatz: Best explanation I have heard in a while! I do need start looking into veil now after this close one!

[takeshi]

(nm)

[Green Voodoo]

Scatter is caused when the coherent beam is travelling through the air. Since the air is not a vacuum it has dust, water, and other crap in there to cause the beam to scatter. That is why fog and rain can reduce the laser beam. That is how the veil system works as well.