What angle should be the standard testing angle? Vote.

**JTW** · 11-02-2006, 11:15 AM

Evolution of jammer testing angles

We've all come a long ways in testing. I remember when we'd test jammers by doing straight shots and that was considered the standard in testing. Then the GoL did a 15 foot angle test, breaking away from norm.

An average lane is about 6 feet wide. What kind of angle do you think should be the standard in testing now? I personally think we should bump the angle to 21 feet, simulating a 3 lane highway with an officer on the shoulder.

JTW

**go.mouse** · 11-02-2006, 11:34 AM

We'll see what's convenient at our test site. It'll be the same road we used for our September test.

**JTW** · 11-02-2006, 11:50 AM

Originally Posted by go.mouse

We'll see what's convenient at our test site. It'll be the same road we used for our September test.

We'll just cut down some trees alex. We'll do it at night so it's harder to get caught ;-)

**licamell** · 11-02-2006, 12:16 PM

as many angles as possible

**happya$$** · 11-02-2006, 03:24 PM

21' is what I was thinking Chris. This is GREAT. Knowledge is power. Great job guys

**Switchback** · 11-02-2006, 03:27 PM

what is the maximum allowable "gun to target" angle recommended in the operating manual of the lidar gun being used?

Than go with that angle, because if the officer is using the gun outside of recommended procedures the court case will be easier to win.

There are no rules carved in stone that specifically state that a leo needs to be within a specific angle of his target.

and most jammer testing videos that i have seen do not in any way show what an actual leo will do to get a speed reading.

**charles charlie charles** · 11-02-2006, 03:39 PM

could someone please explain how an angle is measured in feet?? Angles are in degrees etc, linear distance is in feet surely?

**go.mouse** · 11-02-2006, 03:48 PM

Well, as you approach a laser gun on the side of the road, the angle only gets larger. It becomes 90 deg when you pass the gun. The distance is measured from the gun to the center of the car at such vertical angle.

Originally Posted by charles charlie charles

could someone please explain how an angle is measured in feet?? Angles are in degrees etc, linear distance is in feet surely?

**charles charlie charles** · 11-02-2006, 04:24 PM

OKay go with me on this.....!

The "angle" in question is the angle at which the laser beam strikes the target surface, correct? This surely is the most important angle as it will determine how much reflection is received by the Lidar gun and as such, the ability of the gun to dtermine a vehicle's speed.

e.g. Head on the LIDAR beam strikes the surface of a number plate at 90 degrees.

So, as we, the driver, approach the LIDAR source the angle of incidence of the beam actually decreases towards zero, not increases.

So to my mind an acute angle of LIDAR beam incidence is not only a difficult task for the jammer, but also for the gun too.

I would have said also that considering the usual distance to target that a LIDAR gun is operated, a distance of several feet sideways will have little impact on the angle of beam incidence on tyhe reflective surface and thus not make a massive difference to the results.

just my tuppence worth!

**LittleOverPSL** · 11-02-2006, 04:43 PM

Point noted Charles. Yes, angles in degrees and distance in feet/meters/whatever.

Traffic lanes have got to be more than 6'. Unless we all drive those nifty SmartCars. :P Lanes are probably in the 9'-10' range (these things have to take big trucks too). We can measure them if we want this weekend.

Regardless, the point here is to 'simulate' a real world scenario where a LEO tries not to jump into traffic to take a perfect straight on shot at vehicle (plate, headlight, bumper, mirror, etc). Well not if they wish to cite anyone. Heck, that would be a hilarious video to watch for Statie LEO.

They typically are on the outer side of the road or the median. Often a few feet off the 'edge' since they don't want to be 'kissed' by a swerving vehicle. I'd say that typical LEO is at least 8' away from lane edge, targetting folks across 2-3 lanes on the highway. Or on an overpass which again will require the lidar gun to be about 20' off the road surface below overpass.

So we hold the lidar gun about 8' off the side and drive cars 2 lanes apart (if available) for distance of 28'-30'. Or 1 lane apart for distance of 18'-20'.