# Thread: LI Beam Dimensions?

1. ## LI Beam Dimensions?

Hey I was wondering...

What is the area covered by a LI jammer head at 1000ft?

I know the diode is polarized, and I am trying to picture the coverage in my head.

Thanks,

-Oyu

2. ## Re: LI Beam Dimensions?

This is a good question, and relates to one I've wondered about -- mounting non-recessed so as to have good reception of an over-pass or off-angle type shot... but the dispersion of the responding signal is still straight down the road to whatever dimensions it has... I'm not totally understanding how the counter-measure works in those kinds of Lidar shots.

Cal

3. ## Re: LI Beam Dimensions?

I wonder the same things..

someone help us!

Oh hey Cal, nice car/laser combo. Did you ever post your install pics? I'd really like to see. I think I'm gonna get a 550i and I need ideas. =)

Ty

-Oyu

EDIT:

Nevermind... Found it! http://www.kodakgallery.com/gallery/..._photos_button

4. ## Re: LI Beam Dimensions?

Originally Posted by Oyusan
Hey I was wondering...

What is the area covered by a LI jammer head at 1000ft?

I know the diode is polarized, and I am trying to picture the coverage in my head.

Thanks,

-Oyu
Assuming an Osram SPL PL90_3 (75 Watt) pulse laser is used without lens:

Horizontal around 2x 20deg : (sin(20) * 1000ft) * 2 = 700ft
Vertical around 2x 7deg : (sin(7) * 1000ft) * 2 = 250ft

So this laser would project an oval of around 700x250ft @ 1000ft distance

At the edges the intensity of the laserlight is around 20% of the intensity in the center.

By using a lens in front of the laser, you can change this pattern of course.

5. ## Re: LI Beam Dimensions?

Thank you, this answers my question. I wonder how the LI lense focuses them.. like if they make the beam smaller but more powerful for an area.

6. ## Re: LI Beam Dimensions?

Originally Posted by Oyusan
I wonder the same things..

someone help us!

Oh hey Cal, nice car/laser combo. Did you ever post your install pics? I'd really like to see. I think I'm gonna get a 550i and I need ideas. =)

Ty

-Oyu

EDIT:

Nevermind... Found it! KODAK Gallery | Photo Merchandise
Yes I did: http://www.radardetector.net/forums/...-bmw-550i.html

7. ## Re: LI Beam Dimensions?

Bump

Any comment on the LI's signal beam dimensions related to hitting a Lidar gun on an overpass or serious off-angle? How does that work, anyway, since we work so hard to get the alignment level and down the road?

8. ## Re: LI Beam Dimensions?

Keep in mind that the gun has to look into the beam's source for reflections so it is more than the beam size being projected that comes into play.

9. ## Re: LI Beam Dimensions?

OK... but I still am not "seeing" how the emanation from the jammer diodes hit the off-angle gun to jam, IF it has a similarly tight dispersion dimension. Maybe it doesn't, I'm not sure but someone here surely knows how this works.

10. ## Re: LI Beam Dimensions?

It has to do more than just hit it to jam it. Sunlight "hits" my eyes all day long, but it doesn't blind me until I look straight into it.

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