Laser jammer leds?

Streaker · #1 (**permalink**) 2009-06-26

Just a slight question regarding these leds. If they are 904nm leds, then what is the purpose of the dark purple lenses they shine through? I can understand to spread the light source, but wouldn't clear be better? (stronger light penetration).

I have stripped laser star, ZR3 + 4, blinder m25 extreme and the Lasertec pro 20 and theyall have this purple perspex lens. Some convex and some flat. Locally I cannot seem to purchase 904nm leds, only 850 and 940nm.

If one was to flood your vehichles front and rear with say 850nm floodlights, would a gun still get a reading? My thought here is the security 100m infrared flood lights available in 12v. I imagine the guns have a filter for this, but if the area is to well lit for it to recieve a reply, wouldn't it work?

I am only asking what sems like stupid questions but information on this seems to be very limited here.

steagall1000 · #2 (**permalink**) 2009-06-26

Streaker,

I can answer part of this question, TSi+WRX may have to answer the rest. LOL!! The reason Blinder and escort put dark cover lens on the heads is to make sure not too much sun light comes into the head. "Clear lens covers" would make the jammer perform worse allowing way too much sun light in, which would set the jammer head off all the time and "Blind the jammer". Sun light is a jammers worst enemy!!! Blinder and escort do have filters that help against those bright xenon head lamps which you see on BMW's and infinities. My Blinder J15's use to always go off when a Infinity with a Laser cruise control system was on it. The Blinder M25 J16 and J17's corrected this problem by closing up the filters alittle bit, which allowed less sun light in also. I hope this helps you alittle bit.

Quote:

Originally Posted by Streaker

Just a slight question regarding these leds. If they are 904nm leds, then what is the purpose of the dark purple lenses they shine through? I can understand to spread the light source, but wouldn't clear be better? (stronger light penetration).

I have stripped laser star, ZR3 + 4, blinder m25 extreme and the Lasertec pro 20 and theyall have this purple perspex lens. Some convex and some flat. Locally I cannot seem to purchase 904nm leds, only 850 and 940nm.

If one was to flood your vehichles front and rear with say 850nm floodlights, would a gun still get a reading? My thought here is the security 100m infrared flood lights available in 12v. I imagine the guns have a filter for this, but if the area is to well lit for it to recieve a reply, wouldn't it work?

I am only asking what sems like stupid questions but information on this seems to be very limited here.

Veil Guy · #3 (**permalink**) 2009-06-27

Flooding with IR content appeared to have been more effective with generation I (and perhaps gen II) police lasers in the early-mid 90s.

However, generation III police lasers (and now "IV") are not easily thwarted with such techniques given the advanced algorithms employed by these guns.

Destructive interference (ie; sophisticated laser jammers) and attenuating techniques (ie; Veil) are much more effective against current police lasers.

While we have observed big performance swings with police lasers (and, in fact, countermeasures, as well) during different periods of day-time (sometimes as much as 50% performance reductions, simply due to lighting) as Allen indicated it is variable, flooding the return with IR is simply not an efficient means of counteracting the latest police lidar technology.

Veil Guy

TSi+WRX · #4 (**permalink**) 2009-06-27

^ Hey, where did my post go? :lol:

Streaker · #5 (**permalink**) 2009-06-28

Thanks guys, it is appreciated.