Radar Stealth???

Those speed detector systems take a few seconds to re-set for the next reading - it's likely that it re-set itself just as you went past. It could also be that the radar angle was set too high or too low.

Unless your car is completely made of wood or non-metal materials, radar will see ya!

 

<div class='quotetop'>QUOTE(ekpolk @ Sep 30 2007, 09:37 PM) [snapback]519623[/snapback]</div>

It's quite bizarre, but that exact question occurred to me today. I was driving home, and on my route there's a permanently mounted speed sign in a school zone. There were no cars ahead of me and one behind me. I watched the sign, though it didn't register until I was just passing it, and realized that it must not have gotten a reading on me, but it did on the car behind me. And yesterday, when I was driving the opposite direction, the sign on that side didn't clock me either, and there were no other cars immediately ahead or behind me that time.

I wondered if it's the angle of the hood and windshield that don't give a good radar reflection back, and instead scatter most of it upwards.

Figures, now that I have a car where I almost never exceed the speed limit, and it's invisible to speed rader. <_<

 

I can tell you that the Prius is NOT low observable. Trust me.

 

Plastic bumper may be hard for a radar to "see" by I bet the aluminium radiator, the bulbous curved aluminium bonnet and the aluminium engine block and transmission are clear as a bell in the "eyes" of the radar.

 

Police in Australia use hand held speed detection devices (radar gun)which are a laser distance measuring device which uses the closing distance over time to calculate speed. They work off any solid device and display both speed and distance to target at lock. Lock is when the trigger is released and the speed and distance lock on. I have used the radar guns. They are aimed at the headlights or front number plate for best results.
Fixed speed detection uses wire loops in the road surface to time the vehicle over a fixed distance.
Car mounted speed detection devices use a slant dopler effect radar to measure closing or departing speed, they record a distance to the target on the photograph.

 

<div class='quotetop'>QUOTE(ekpolk @ Oct 1 2007, 06:59 AM) [snapback]519752[/snapback]</div>

My Prius gets picked up just fine by the local speed signs, but obviously the Prius has a lower return than a truck or boxy SUV. The frontal area of the Prius is well sloped with only a small radiator mounted very low. I have noticed in traffic that the speed signs tend to stay with the vehicle in front or jump to a following one, locking onto the Prius for a shorter than expected time.

As for your V1, have you considered mounting a couple of HARMs on a roof rack? I think it would help.

Tom

 

<div class='quotetop'>QUOTE(patsparks @ Oct 1 2007, 07:17 AM) [snapback]519754[/snapback]</div>

That is not "radar", but "laser" - radar uses radio frequencies that bounce off targets, laser uses collimated light. Laser systems rely on hitting solid objects that reflect light, while radar can go through some materials and still reflect frequencies.

I think laser speed detectors are more dependable when used correctly, since you can aim the light at specific points in the car - radar uses wide beams and may be affected by shape and materials.

 

<div class='quotetop'>QUOTE(ekpolk @ 2007 09 30 20:15) [snapback]519651[/snapback]</div>

Would that explain the bits of wrinkled metal foil all over your radiator? Or the Christmas tree tinsel woven into your sound-deadening material?

 

i pass one of those signs a couple of times daily, and it never fails to see me.

 

LOL.. the dispensed chaff might very well earn you a ticket for littering instead of speeding. :lol:

Didn't they try that on Mythbusters? A chaff dispenser on a car in an attempt to foil radar. I'm pretty sure they did 2000 things wrong with their experimental setup, but as a simple garage-tinkerer attempt it definitely didn't work..

Maybe see-through gold leaf coatings on the inside of the windows and headlamp housings to decrease their RCS would help? I think that's what Lockheed used to coat the cockpit window panes on the F-117A to prevent radar waves from getting into the cockpit and getting a return off the pilot's head. The coating gave the windows a cool-looking tint too.

It'd be cool to see an aftermarket panel kit that puts sawtooth edges on the car, radar-deflecting grills (like the intakes on the F-117), and faceted body panels. B)

 

<div class='quotetop'>QUOTE(JustLurkin @ Oct 1 2007, 12:22 PM) [snapback]519834[/snapback]</div>

I hope that was an accident and not a really, really bad pun. :blink:

Tom

 

I pass those radar signs often... and the distance my detector picks up the same ones varies greatly, I can't find any reason sometimes I pick them up a mile away and sometimes a couple hundred feet away. Maybe they go into a low power mode after a given time of inactivity. They usually give me my speed accurately though. Many here on PC claim radar detectors are not needed. I guess they don't pulse up to 40 in a 35 zone before gliding??? That's all it takes to get tagged here. And I guarantee the coppers will see your Prius on their radar guns.

 

I've set those speed signs off while riding my bicycle. There is a downhill run near my house that is advertised at 35, but most ppl drive 50. I got it to show 36 while riding my bike, which I thought was cool. My Prius does register the same as everybody else's car when I drive it past the sign. I'm not radar stealth, and neither is my car.

 

Hi All,

What might explain this is the roadside sign antenna was slightly uptilted. From the top radiator slot on upward a Prius is low observable by radio reflection. So, if the antenna was iluminating only that portion of the car, that jives with the experiences. If the radar is point horizintally, it illuminates the radiator, lights, and license plate. All good reflectors.





Of course that is useless for avoiding tickets, except possibly by mis-adjusted automatic systems. A police officer is going to aim that radar right at your front plate / radiator. which will give a really good reflection.