Quote:
Originally Posted by Bill R  I have had a Blinder M40 and it has jammed over pass shots quite well, but the LEOs were using PL3s - which are the easiest laser to defeat. |
Much depends on the mounting position of the heads and how close you are to the overpass. Are your heads recessed at all? Look at your car from a 30 degree angle looking down. That is about the max. angle they can tag you at. Even then it's actually going to produce significant cosine error, but they may get a reading.
Since this is posted in an a LPP thread, I'll mention one big advantage of LPP is its coverage map is very large compared to most other products.
IRCMUSA demonstrated this in his videos, which seem to have disappeared from the Net.
Regardless, I believe Dave is correct that LED systems will be at a disadvantage - from the reception/coverage perspective but also from the fact that the incoming threat is going to be brighter and at close range you will get better performance from laser diode vs. LED diode.
Personally, I don't like overpass shots from a law enforcement perspective. Why? Because you have the potential for cosine error to be introduced from two angles... vertically and horizontally. For example, if the LEO is at the edge of an overpass let's say, pointing down. They will be off zero axis in two directions.
Ordinarily, this will not be a problem you might say, but the question is what is the range they are targeting? At short range you increase the possibility of this bi-directional cosine effect. Laser has very little case law compared with radar systems, and unfortunately it's going to continue to be a bit of the "wild west anything goes" until we see some hard fought battles carve out the rules for LEOs. Most LEOs think they understand cosine but they are not used to thinking about it as they are setting up a speed trap. Most of the time it's a non issue, but due to laser's pin-point nature, IMHO it increases the likelihood of improper use of the device.
Of course I know that cosine favors the motorist, but that is not the point. The point is it produces erroneous speed readings, which should not be accepted as evidence because they are wrong.
Same reason I can't stand the SPECS devices (which measure your average speed over a given distance over time). They don't accurately indicate your real speed, but rather your average speed which you were probably not travelling. Thankfully, they are very rare if used at all in the States (at least right now). But if they are allowed in courts, one ought to argue that they only make sense if speed limits follow the same rule. Otherwise the measuring stick does not match the ruler so to speak. Yet if we allowed speed limits to mean "average" speed on the road, then all the speeding tickets should be thrown out unless you're being paced. After all, who's to say that if you are doing 75 mph in a 55 that you were not traveling at 35 mph on the same road for an equal distance earlier, thereby equating your "average" to 55?
Just imagine, better not pass anyone so you can squeeze into the lane you need to use, or you might get a ticket. WTF??
SPECS is a Pandora's box that should just stay in the box.