Radar setup angles

[dhunt]

A question for the cops on here. We've been studying a bit about radars lately and was looking at how the angle in which the radar beam is directed must be taken into account to accurately determine speed. What we were discussing is what happens as the angle increases the determined speed will drop. Do you guys taken anything like this into account?

-------------------------------

Road    / *vehicle1

       /

*cop / ______________*vehicle2

--------------------------------

If vehicle1 and 2 are traveling at the same speed if the angle isn't taken into consideration then vehicle1 will seem to be travelling slower to vehicle 2.

If none of this makes seens to anyone just ignore me. I'm just bored at work.

[Hoon]

I wouldn't think so. It works to the drivers benefit anyway as their indicated speed would be lower than their actual speed as the angle increases (Vi = V * Cos Ø).

[spudchucka]

Any angle works in the favour of the targeted vehicle. If there is multiple lanes of traffic then you need to visually confirm which is the fast vehicle. Laser can be aimed at a specific vehicle so you don't have to deal with that issue.

[dhunt]

I wouldn't think so. It works to the drivers benefit anyway as their indicated speed would be lower than their actual speed as the angle increases (Vi = V * Cos Ø).

Yeah that's what I figured.

[marty]

hoon is right. cosine angle is always advantageous to the vehcile being tracked.

[Lou Girardin]

Not quite, cosine error works to the advantage of the target vehicle when it is closing the angle to the patrol car, eg the patrol car is travelling straight and tracking a target approaching on a curve. The opposite is the case when the patrol car is on a curve with the target vehicle approaching in a straight line. Then the radar over-reads.
Don't believe what they tell you at training college boys. One of your bosses, John Kelly, doesn't even know what frequency Stalkers operate on.

[spudchucka]

One of your bosses, John Kelly, doesn't even know what frequency Stalkers operate on.

Why the hell should he? Its not like he goes out and uses the bloody thing! What difference could it possibly make?

[marty]

Not quite, cosine error works to the advantage of the target vehicle when it is closing the angle to the patrol car, eg the patrol car is travelling straight and tracking a target approaching on a curve. The opposite is the case when the patrol car is on a curve with the target vehicle approaching in a straight line. Then the radar over-reads.
.

isn't that what i said?

get a couple of matchbox cars out lou, and do the math in visual symphony, as obviously your tiny brain can't compute it without external input. if the vehicle being tracked (that's you) is travelling at an angle to the vehicle doing the tracking (that's the police - they're the ones in the patrol cars - can you say patrol?), then the cosine angle is advantageous to the vehicle being tracked. there is no circumstance when the radar will read HIGHER due to the angle, regardless if the patrol car is on a corner or on a straight.

[StoneChucker]

What happens if you're on a bike, and doing a wheelie? IF you pinged under the bike, depending on the angle of your wheelie, it would read differently right? SO... If I get pinged doing a wheelie, should I accelerate to decrease the angle (lift bike higher) or touch the rear brake to increase the angle (lower bike). Note angle I mean is angle between laser and bottom of bike, so no angle would be doing a verticle wheelie.

So, which is best, so I know for the future?







hehehehehehe

[spudchucka]

I think you should just stand up, lift one leg in the air and wave as you zoom past.

[marty]

i'd certainly wave.

[Blakamin]

What happens if you're on a bike, and doing a wheelie? IF you pinged under the bike, depending on the angle of your wheelie, it would read differently right? SO... If I get pinged doing a wheelie, should I accelerate to decrease the angle (lift bike higher) or touch the rear brake to increase the angle (lower bike). Note angle I mean is angle between laser and bottom of bike, so no angle would be doing a verticle wheelie.

So, which is best, so I know for the future?







hehehehehehe

which is better??? laying it in a gutter ??

[StoneChucker]

I think you should just stand up, lift one leg in the air and wave as you zoom past.

If I waved, would ya chase me?

[spudchucka]

If I waved, would ya chase me?

The only bikers I've ever chased are the types that stink real bad and wear patches on their backs. I've heard it heaps of times over the radio where a cop calls up to say that he just clocked a bike at 240'ish. Ask for a description....."I think it was a red one"! Roger, we'll keep an eye out for a red bike.

If you went past me like that I'd be saying, "There aint no way I'm going to catch that guy so I might as well enjoy the show".

[scumdog]

The only bikers I've ever chased are the types that stink real bad and wear patches on their backs. I've heard it heaps of times over the radio where a cop calls up to say that he just clocked a bike at 240'ish. Ask for a description....."I think it was a red one"! Roger, we'll keep an eye out for a red bike.

If you went past me like that I'd be saying, "There aint no way I'm going to catch that guy so I might as well enjoy the show".

My sentiments exactly s.c.!!!!

BTW Lou, I'm still waiting for a scientific refuting of the argument on how the radar gives a lower reading for a target vehicle approaching a patrol vehicle on an angle than it's actual speed really is.

p.s. , Got 18% in School Cert maths so I shouldn't be too hard to fool!!