[Travis McGee]

I think the laser would go right through the flat glass and find the cuved lenses and report back "SNIPER! FIRE!"

[Squantos]

I have experience with laser mic's and if a surface is reflective it is reflective regardless of the filters unless a very powerful laser is used to go through. Such as the Co2 lasers we used to cook off landminds in experimental EOD rendersafe procedures.

I'm still thinking the key to the "best" countersniper systems is "sound". The above pic I posted seems to have a system on the tripods that will, with the use of a puter , trianglulate the source based on the frequency of a set of possibles to include those using a can/supressor/silencer.

Way too many iron sighted possibilities to waste duckets on a system based solely on optics IMHO. Supersonic velocities supressed by a silencer/supressor will fool the human ear as to direction unless your operating in a closed end pipe. But , again IMHO, they won't fool good acoustic sensors.

Just my two cents based on my doubt that a really good systems "how it works" will not be revealed to the masses.

Stay Safe !