How radar stealthy are our cars?

[shay2nak]

LOL awesome story OP

In malibu they have these speed limit signs that have attached radar showing your speed and my car activates it, never tested distance wise since always traffic around, but maybe 20 ft away it comes on.

[Tickle]

I've been pulled over at least twice by cops who said that they couldn't get a lock on me, but knew I was speeding. All times the cops were extremely correct; each time I was doing at least 30 over.

I always thought my '79 Esprit was slightly steathy due to the fiberglass (a Dielectric composite) and foam bumpers (Nerf Technology FTW!) being relatively transparent to radar.

When I worked for Northrop Grumman, I tried several times to get my Esprit into the Anechoic chamber to test it with our radar sim systems. ...Got busted both times rolling it in.

That said, one of our radar geeks thought that it could have somewhat steathy in that the shape could divert the reflecting radar away from the source - however, they pointed out that too many internal metal reflective structures existed for the car to ever be really considered steath (or steath like).

[plastique999]

CO is not stealth at all...
3 tickets in 3 months ....

[Flareon]

Originally Posted by lotusforsale

I think this is one of those that Myth Busters should cover once and for all.

YouTube - Mythbusters Rocket Car vs Traffic Speed Camera

They actually did several episodes with the speed camera. There was another where they tried to pit a Lamborghini Murcielago against the camera. Unfortunately YouTube has failed me, and I cannot find that clip. But the Lamborghini got the ticket.

Annotated Mythbusters: Episode 73: Beating the Speed Camera, Exploding Nitroglycerine Patches (with Defibrillators)

Would love to see an officer's reaction to the rocket car down the highway, tho.

[Simba]

The cars are perhaps slightly harder to read with radar given the unconventional size and body, but any cop should be able to get a radar reading in any kind of normal situation.

Where the Esprit in particular becomes stealthy, especially in dark colors, is against laser. If you have no front plate and the headlights are down, it's extremely hard to target the front of the car. All that one can really get at are the turn signals and fog lights, and those are pretty small. Other target points like the mirrors are also difficult to hit, and the wedge shape of the front hood and windshield is particularly good at refracting light.

I've had more than a few occasions in a black Esprit where I was going.. ur.. "quick" and sailed right through laser traps.

Radar is unfortunately another matter.

[Scrumpot]

Originally Posted by lotusforsale

At the time I owned a Fiero, and when seeing the car they both said that they can't pick them up on radar. Go figure.

My eldest son last week picked up a ticket, it seems specifically because the radar operator/officer told him he MUST HAVE DONE SOMETHING ILLEGAL by not appearing on her radar, pointed straight at him, as he was driving my (given to him) fully restored/reconditioned '86 Fiero GT. So she wrote him for an ESTIMATED 46 in a 30 zone. Obviously, a ticket we are going to go to court on and beat. I mean, c'mon now... how in the heck do you "estimate" exactly 46 ...and too, hello - it's a really sharp looking FieroGT, if I do say so myself.



Apparently though, she gave him a TON of grief over it all as a result too. I don't think my son helped himself out any, by reporting to her, that he had "seen" her though, on his V1, and noticed as well that she had even switched her bands on her gun 2-3 time's as he was approaching (he says she even flipped once quick to the old "X" band, apparently in an effort to read him) - and that maybe it was just her inept operation of the gun, that caused it!

She held him up for nearly an hour, while she called in a K-9 unit to "sniff" his car, etc. etc. - she was so ticked.

Anyhow, I doubt the car itself really had anything to do with this (other than irking the officer's clear and obvious ire - I agree with my son's assessment, although myself would have never verbalized it like that, directly to her either!) - Just another anecdote on that Fiero legend, I thought I'd add in here now then, and share. FWIW.

[ezmoney]

Originally Posted by apk919

We need to know what <b>kind</b> of leaves! Presumably pine needles won't do...

Cannabis? Coca?

[EliseSC]

For anyone who thinks their car is stealthy or invisible to radar and laser, here's a great website that should be very helpful: Traffic School Online - The Cheapest Online Traffic School

[Scrumpot]

Originally Posted by EliseSC

For anyone who thinks their car is stealthy or invisible to radar and laser, here's a great website that should be very helpful: Traffic School Online - The Cheapest Online Traffic School

Oh yeah, I'd trust THAT site!

Can't even spell THEIR OWN site/domain name right, for starters.
Direct Quote off this site itself:

"See for yourself what people all across the country are saying about GoToTrafficSchoo.com"...

[serpent]

Scrumpot, nice story and good ending. When did this happen?

i got pulled over on muncaster mill rd and she told me that i didnt appear on her radar and that i was blocking it somehow. I told her to do whatever she wants and that i can beat her easy in court(that pissed her off even more). Then another guy came out and basically told her that if she doesnt have me on radar then she cant do anything(i'm guessing it was a senior guy). She basically let me go..lol

[Noisycow]

I really enjoyed watching the Beast, thanks for the vid.

[TimMullen]

Our cars may be a bit less "visible" than most cars, but they are far from undetectable. I know that when they set up one of those radar (Ka band) speed monitoring trailers (the kind that show you speed as you approach), they have no problem "seeing" my Elise and displaying the speed. I've even turned around so that I could approach it again with no other cars around in an effort to determine when it first detected my car. The bottom line was that as soon as I had a straight line view to the trailer (at least a couple hundred yards), it could display my speed without problem.

[Flareon]

Originally Posted by TimMullen

Our cars may be a bit less "visible" than most cars, but they are far from undetectable. I know that when they set up one of those radar (Ka band) speed monitoring trailers (the kind that show you speed as you approach), they have no problem "seeing" my Elise and displaying the speed. I've even turned around so that I could approach it again with no other cars around in an effort to determine when it first detected my car. The bottom line was that as soon as I had a straight line view to the trailer (at least a couple hundred yards), it could display my speed without problem.

On the other hand, I've seen those things report 74 mph in a 5mph traffic jam. Sadly, I've never crossed one of them by myself. Always with others around, so I never know whose speed it's reporting. They seemed to be turned off at night when it's a clear road.. either that, or their double digit display doesn't take triple digit speeds too fondly.

[dstevens]

Over the weekend I observed a road-side speed display pick up the a cyclist at 33mph in a 25mph zone. Seemed about right as it was a racing bike going downhill. Anyhow, it seems the radar is sensitive enough to pick up a cycle fairly easily from a reasonable distance.
BTW the signs around me only show the speed up to 10mph over the limit, and then just flash 'slow down'. Also I always find that they read about 2 mph over your true speed from a distance, then reduce the displayed speed until they are dead on as you pass them

[jhnmdahl]

Radar works by receiving back a frequency-shifted version of the signal that was sent, so the key is not sending back the signal (i.e. absorbing or diffusing it, or reflecting it somewhere else). Stealth vehicles do this by absorbing some radar waves, such as with radar-absorbing paint having small particles that absorb certain frequencies, and by carefully controlling the direction in which any reflected waves are deflected. One could perhaps use metal reflectors carefully angled not to reflect radar straight ahead or behind the car, hidden under a clamshell that has a layer of radar absorbing material paint under the color coats and be truly pretty stealthy.

For laser, speed is measured by changes in the time of flight for pulse to be received back at the laser gun over a series of a large number of pulses. Not having a front plate or other obviously reflective, flat surface makes the car harder to pick up with laser, especially over the second or so that it takes to gather the tens of pulses typically used to determine speed, but there's no practical way avoid it entirely without illegal active jamming.

John

[dstevens]

'Shunk Works' by Ben Rich has some information about the mathmatical model developed in the 70s to determine the radar return from a shape, which was used in the F117A stealth plane. One amazing fact from the book was that the F177A had the same radar return of a 1/8" ball bearing.

[habendanio]

Originally Posted by Scrumpot

My eldest son last week picked up a ticket, it seems specifically because the radar operator/officer told him he MUST HAVE DONE SOMETHING ILLEGAL by not appearing on her radar, pointed straight at him, as he was driving my (given to him) fully restored/reconditioned '86 Fiero GT. So she wrote him for an ESTIMATED 46 in a 30 zone. Obviously, a ticket we are going to go to court on and beat. I mean, c'mon now... how in the heck do you "estimate" exactly 46 ...and too, hello - it's a really sharp looking FieroGT, if I do say so myself.



Apparently though, she gave him a TON of grief over it all as a result too. I don't think my son helped himself out any, by reporting to her, that he had "seen" her though, on his V1, and noticed as well that she had even switched her bands on her gun 2-3 time's as he was approaching (he says she even flipped once quick to the old "X" band, apparently in an effort to read him) - and that maybe it was just her inept operation of the gun, that caused it!

She held him up for nearly an hour, while she called in a K-9 unit to "sniff" his car, etc. etc. - she was so ticked.

Anyhow, I doubt the car itself really had anything to do with this (other than irking the officer's clear and obvious ire - I agree with my son's assessment, although myself would have never verbalized it like that, directly to her either!) - Just another anecdote on that Fiero legend, I thought I'd add in here now then, and share. FWIW.

Cool to see another owner of a lotus and an 86 Fiero GT.
I can say for certain the the fiero is by no means invisible to radar, but I've never got any tickets in the lotus.

[Simba]

Originally Posted by jhnmdahl

... but there's no practical way avoid it entirely without illegal active jamming.

Jamming laser is perfectly legal in most states.

[carbuff]

Originally Posted by Flareon

On the other hand, I've seen those things report 74 mph in a 5mph traffic jam.

Here in Netcong NJ, the State Police BARRACKS building was clocked at 26 MPH by speed radar!

Q. How do they go to the bathroom in there without falling off?








A.. They are highly paid professionals.

[alil'britdifferent]

Originally Posted by darkSol

I fully believe that laser is highly ineffective against our cars - there's really no flat surface for the beam to bounce off it.

I have a laser jammer, but have only had it activate once. Since it activated I assumed that the cop had a lock on me, but can't be sure.