quick question

**theguysaid038** · 12-19-2007, 04:15 PM

okay

so i was driving... i saw a cop pointing their radar guns at cars...

how long does it take the radar guns to tell the cop the speed ur car is at?

5 sec? 10? 2?

plz tell.

thx!

**jdong** · 12-19-2007, 04:33 PM

If you can see the cop, at that distance probably 0.5s or 0.25s -- it'll take longer for a human to parse the number displayed on the screen and compare it mentally with the speed limit.

If you see a cop physically aiming a device, it might be laser too. Unless it's a motorcycle unit most cops like the convenience and non-sore arms of a dash-mount radar head and you won't see much aiming action.

**theguysaid038** · 12-19-2007, 04:36 PM

hmm

so...

whats the different between laser and radar...

i mean i know laser is within 1 second

radar is kinda like that as well?

and funny thing is i have been driving lately, i see a lot of cops just aiming

and sometimes i dont see any cops but my KA band goes wild on the X50 i am sure theres a lot of cops where i am living.. its not fun.

thx for ur help.

**jdong** · 12-19-2007, 04:45 PM

The main difference is that radar beams quickly cone out to the width of the road so the officer can just broadly point in the right direction and the radar gun will read speeds of whatever object it likes, which tends to be either the fastest , closest, or largest object depending on settings. Radar waves bounce off any metallic (or reasonably large like a bike/car) object. This uncertainty is argument ground for probably most of radar-related speeding tickets.

With laser the beam within targeting distance is probably just the width of the car if not less, so an officer needs to carefully aim at a reflective surface. Laser can only bounce off surfaces that reflect infrared light, which at a distance means only reflective layers like headlights or license plates, but at some critical punchthrough distance it'll be able to target any surface if your car the officer points at.

Does the gun have a glass lens (or multiple glass lenses)? Is the officer looking like he's aiming it very carefully like looking through a scope/viewfinder? If so then it's surely laser.

If he's holding it at like arm's distance and the gun's end looks flat, then it's probably handheld radar.

Laser's acquisition, once you aim at a properly reflective surface like a headlight/plate or are within a critical distance of a few hundred feet, will acquire your speed within a few fractions of a second. Of course, the officer might shoot before he has a steady aim and the time it takes for him to re-center his aim might give you a second or two of reaction time.

Digital radar guns (i.e. all modern guns) within the range you can see an officer will lock on nearly as fast, but probably not as fast.

In either case, if you're hoping to change your speed after visually seeing an officer with any speed measurement tool, it's probably too late. Instant-on and laser can be really deadly.

**theguysaid038** · 12-19-2007, 04:53 PM

hmm

u have provided a very detailed explanation. i thank you deeply for that.

it seems like most cops around my area usse handheld radars.

i have only been shot by laser once. so ya.

this is a pretty stupid question...

the cop doesnt have to be in front of u to get the speed right? they can be on side as well as behind?

... ya.. thx!

**jdong** · 12-19-2007, 05:47 PM

Originally Posted by theguysaid038

the cop doesnt have to be in front of u to get the speed right? they can be on side as well as behind?

... ya.. thx!

The cop does not have to be directly in front of or behind of you to clock you, correct. However, the speed he reads will be the "parallel" component of your speed with respect to the officer. In other words, he will read a lower speed the more off-center he is from your vehicle. From the side, he'll read a very low (near zero) and hence useless speed, but of course as soon as you pass him he'll be able to read your speed again with fair accuracy.

Radar and laser both work from the front or back. Radar, in particular, can be used while the patrol car is moving, either behind or even in front of you, in same-direction or opposite-direction traffic.

**theguysaid038** · 12-19-2007, 05:49 PM

whoa

didnt know it would work even if the patrol car is moving.

okay okay.

probably last Q.

if it works in patrol car

why VASCAR?

**jdong** · 12-19-2007, 05:54 PM

Originally Posted by theguysaid038

if it works in patrol car

why VASCAR?

VASCAR is a totally passive measurement tool that transmits no signals whatsoever. Think of it as the $2000 government-overpriced edition of a stopwatch and a 4-function calculator that your tax dollars are being spent for.

The advantage of VASCAR is that it is not defeatable or detectable by any countermeasure short of dropping a big blanket over the patrolcar. The disadvantage is that it takes the human error factor in the speed reading to a whole new level.

**djrams80** · 12-19-2007, 05:55 PM

VASCAR is basically a LEO timing your vehicle between two fixed points. VASCAR allows a LEO to aquire your speed accurately without the use of any radar or laser, therefore, even those of us with top of the line RD's will not have any warning whatsoever.