Laser beam width program: Download

[Orbital75]

Very nice Program Sethy....

I'll save this one with Jim's Radar Distance Calculator.

[carter840]

i hate to bump, but any takers?
they'll probably ask me to back up my sources if i present it..

I believe that the manufactures tell the beam divergence somewhere in their specifications. I think i have seen beam divergence on the LTI website or something.

[y2kvette]

Nice chart sethy - Brings up a few questions

1. At what distance do most LEO's try to target cars? Would seem inside 500' or even 300' would be common?

2. I'm assuming 18" at 500' is diameter of a circle. If so, a jammer would have to be within 9" of the center of the laser aim to detect it. That's a pretty small distance on the front of some cars. And at 300' it's a little over a 5" area it covers from the center of the laser aim. So, say if a laser gun is aimed at the center of your license plate you would have to have a jammer within 9" (at 500')of the center of your plate to detect the laser. When you think of it this way that 18" spread at 500' seems to get even smaller. I would guess that since you are a moving target and if the laser gun is not completely steady that would account for some "grazing" of the laser beam before it gets a lock and giving the jammer a better chance to be hit by the laser beam. ?

3. Do laser jammers send out signals continuously, or do they only transmit when hit with a laser beam from the LEO's gun? I assume they only react when hit with the laser beam. The reason I ask this is it seems if jammers were on all the time (sending signals) they would be more likely to pick up a laser gun aimed in their direction.

[jimbonzzz]

1. At what distance do most LEO's try to target cars? Would seem inside 500' or even 300' would be common?

It depends. More commonly laser is used under 1/4 mile, but sometimes out to 2000 feet and even further. Short-range targeting (< 500') is common in some areas.

2. I'm assuming 18" at 500' is diameter of a circle. If so, a jammer would have to be within 9" of the center of the laser aim to detect it. That's a pretty small distance on the front of some cars. And at 300' it's a little over a 5" area it covers from the center of the laser aim. So, say if a laser gun is aimed at the center of your license plate you would have to have a jammer within 9" (at 500')of the center of your plate to detect the laser. When you think of it this way that 18" spread at 500' seems to get even smaller. I would guess that since you are a moving target and if the laser gun is not completely steady that would account for some "grazing" of the laser been before it gets a lock and giving the jammer a better chance to be hit by the laser beam. ?

Yes, unstable targeting helps out. But although the "18 inches at 500 feet " is a good rule of thumb for mounting your jammers, most can detect the laser outside of this "hot part" of the laser beam.

3. Do laser jammers send out signals continuously, or do they only transmit when hit with a laser beam from the LEO's gun? I assume they only react when hit with the laser beam. The reason I ask this is it seems if jammers were on all the time (sending signals) they would be more likely to pick up a laser gun aimed in their direction.

SOme jammers send out "parking signal" pulses all the time, but jammers only transmit a jamming signal when targeted by police laser. This is because the jamming pulses must be precisely timed with the incoming laser gun pulses in order to have a jamming effect against the gun.

I'm not sure why you think that a jammer that is constantly transmitting would receive better?

[y2kvette]

I'm not sure why you think that a jammer that is constantly transmitting would receive better?

I just noticed where the Blinder says it transmits constantly, then locks on to a laser pulse when it finds one. Don't know if just crossing beams would give you any signal? before they actually hit you. Maybe give you a little more advance notice?

[ragamix]

nice program. any chance you could add metric units as well?

[g-zona]

nice program. any chance you could add metric units as well?

X2, but isn't that linear change? Just substitute it with mm/cm/m ?

[ragamix]

nice program. any chance you could add metric units as well?

X2, but isn't that linear change? Just substitute it with mm/cm/m ?

hmm now i don't really know.. i guess no as there are 12inches per foot but i'm just unable to think about it now after i just had lunch

[Tiho]

metric

[eire05]

What formula is being used to calulate the beam width??