904nm lense covers

[Q Ship]

I have heard of lense covers that fit over lights that show no visible light but send out infrared light instead. Do these exist ? and would they have any affect on LIDAR speed measurment equipment ?

I know from military service that some of the M113 APC's and other tracked vehicles had lights to aid in nightvision equipment use. Would these or a similar civilian version do anything for use against LIDAR equipment ?

Sorry if these are simple questions or have been asked before but I searched and couldn't find any posts on IR lense covers or lights.

[jimbonzzz]

I have heard of lense covers that fit over lights that show no visible light but send out infrared light instead. Do these exist ? and would they have any affect on LIDAR speed measurment equipment ?

I know from military service that some of the M113 APC's and other tracked vehicles had lights to aid in nightvision equipment use. Would these or a similar civilian version do anything for use against LIDAR equipment ?

Never heard of lense covers that do such a thing...

The techniques you mention would have very little effect, if any at all, on police laser guns. Most guns are around 50W peak power (but only for a short 20-50ns pulse, so it is relatively safe). The continuous infrared sources would be much lower power than this, and would easily be filtered by the guns (They would adjust thresholds etc if even that was necessary). The amount of continuous infrared that would be necessary for a gun to have trouble seeing it's own pulse return would probably be many watts. Even if such a thing were to be built, it would be very hazardous, and would probably blind anyone nearby.

[Q Ship]

Thanks Jimbonzz for the clarification. I suspected it was an internet fantasy when I couldn't find anything in a search here but figured with the military use of similar lights it was worth it to ask.

[mikicz]

Most guns are around 50W peak power (but only for a short 20-50ns pulse, so it is relatively safe).

I found this technical info for ProLAser III:

Laser power (mid power in 30mm beam): typical 22.10-6 W, max. 27,5.10-6 W

so this is in mikrowats, not wats. do you have any other informations about this?

[jimbonzzz]

Most guns are around 50W peak power (but only for a short 20-50ns pulse, so it is relatively safe).

I found this technical info for ProLAser III:

Laser power (mid power in 30mm beam): typical 22.10-6 W, max. 27,5.10-6 W

so this is in mikrowats, not wats. do you have any other informations about this?

Yeah that is just average power...
Here's some info:
http://www.radardetector.net/viewtopic.php?t=9899

[mikicz]

thanks

[Vonkie]

Mmmmm... the thing is how sensitive are the receivers of these guns. Although a powerful pulse is emitted, how much returns to the gun??? Especially if the gun is angled to the direction of travel of the car (meaning most of the pulse will be reflected away from the gun). And then you have curved surfaces which will dilute the reflection even more.

For what max reflection are the guns designed for??(% of the power of the transmitted pulse)

My opinion is that these receivers (together with the optics) are very sensitive, so it should be easy to "confuse" it with a certain level of "noise". The threshold adjustment must have a level where it peaks out.