anyone got "real world" numbers for the radar / laser profile of the c6 ?

-zig

 

here ya go!! http://www.radartest.com/article.asp?articleID=9090

 

I dont think thats what he was asking for...he wants to know how much of a "reflection" does the c6 have. I think.

 

You're correct Yogi. Or, at the least, that is indeed what the "radar profile" or radar signature of a vehicle would define.

~ BA

 

that's correct. i'm interested in knowing what type of reading one would get from striaght on and from the side. and how it compares to actual speed, etc. i suspect a rear reading is gonna be pretty accurate (kinda flat back there+license plate).

-zig

 

Zig:

The only "reading" that traffic radar will obtain of your, or any, car (assuming the radar is properly calibrated) is the speed of the car within a fraction of one mile per hour. It will only be able to acquire that data from either the front, or the rear of the car. It will track the car's speed with equal accuracy whether the car is approaching or departing from the radar's antenna. The configuration of the vehicle (i.e. flat rear or streamlined front) is not a factor at all because the radar, in the case of a Corvette with a fiberglass body, penetrates the body and reflects back to the radar antenna from the engine and other metal in the car. On a car with a metal body, it would be reflected by the body itself. Traffic radar cannot detect the speed of a vehicle from the side. There is a factor known as the "cosine" angle that refers to the angle of the radar antenna relative to the vehicle. If that angle is too great, the radar cannot accurately measure the speed. But if I recall correctly, it is a very small angle and not really germane to a general discussion of this subject.

Hope this helps.

 

Zig:

The only "reading" that traffic radar will obtain of your, or any, car(assuming the radar is properly calibrated) is the speed of the car within a fraction of one mile per hour. It will only be able to acquire that data from either the front, or the rear of the car. It will track the car's speed with equal accuracy whether the car is approaching or departing from the radar's antenna. The configuration of the vehicle (i.e. flat rear or streamlined front) is not a factor at all because the radar, in the case of a Corvette with a fiberglass body, penetrates the body and reflects back to the radar antenna from the engine and other metal in the car. On a car with a metal body, it would be reflected by the body itself. Traffic radar cannot detect the speed of a vehicle from the side. There is a factor known as the "cosine" angle that refers to the angle of the radar antenna relative to the vehicle. If that angle is too great, the radar cannot accurately measure the speed. But if I recall correctly, it is a very small angle and not really germane to a general discussion of this subject.

Hope this helps.

 

I'm not so sure about this. I have done some work in radar, and even if the radar does penetrate the fiberglass, it would lose amplitude going in and out. In addition, the engine/etc are not all that flat to transmit a signal back. There have been posts on here from police officers that state the Vette is VERY hard to hit from the front, and if there is a car next to you (you are passing on the interstate), the radar will 99% of the time pick up the other car.

I could be wrong, but from my experience with radar, the engine compartment would not be something that would give a good reading.

 

I can't find links to the article(s) now, but it was a well documented fact during the C5 development that things like placement/slant of the radiator were done with reducing the car's radar cross-section/signature in mind.

Yes, the engine is alloy and radar reflective as someone above pointed out. But, so is the radiator equally radar reflective and with the benefit of being placed in front of the engine.

Regards,
BadAttitude

 

I can't find links to the article(s) now, but it was a well documented fact during the C5 development that things like placement/slant of the radiator were done with reducing the car's radar cross-section/signature in mind. So I would highly suspect the same care was given to the C6, it only stands to reason.

Yes, the engine is alloy and radar reflective as someone above pointed out. But, so is the radiator equally radar reflective and with the benefit of being placed in front of the engine.

Point being, yes the Corvette has a smaller radar cross section than "average" and it's not by accident.

Regards,
BadAttitude

 

First off, Zig, all your posts seem to have a sinister mark about them. What are you up to brother?? Radar reflectivity, blacking out lights. Are you stealthing your Vette!! ??

As for the rader questions, let me start off by saying I have somewhat of a working knowledge of military targeting and tracking radars, and have used them for the past 5+ years. Fang is absolutely correct.

Imagine standing next to a train track and listening to a train approaching with it's horn blasting. Now as the train passes (with the horn still blairing) you will hear a different "pitch" or sound from the same horn...right. That attribute is called Doppler, and it's the same physics of how a copper's radar tracks your car. The radar uses Dopper shift, and can pretty much only pick up an object that is (for the most part) moving directly at it/or away from it. It measures the difference in time for the radar wave to hit your car, and return. The time delay is the Doppler-shift, and with a little bit of math, that time delay equals your speed.

If the copper hits your car from the side at, say a 90 degree angle, the relative motion to or away from him is zero. So your speed readout will be zero. Does that make sense?

As for the radar reflectivity of the Vette, it's tough to say. The entire mass of an object exibits some radar reflectivity. The fiberglass and plastic might be some of it, the engine and tires might be another part. But all of it combines together to form some sort of "radar picture" that the radar gun can "see." Who knows just how big or small that signature really is and what causes it. For instance, the F-117 Stealth Fighter reflects radar energy, but the funky angles and such on it combine to reflect the energy in a different direction so enemy radar can't "see" it. Everything reflects radar energy, it's just a matter of what is absorbed, and what is reflected straight back and what is reflected off elsewhere. Guess that's why the Gov spends all that $$ of perfecting Stealthy aircraft.

Sorry, Radar 101 class is finished for the day...your homework, go drive your Vette!

 

you got your f16 i got my f55.



-zig

 

You are correct. The C5's signature is one of the lowest for both radar and laser when the lights are down and with no front plate or fog lights and with non-metallic black paint. The C6's signature would be slightly higher due to the exposed lights.

Radar and laser signatures aren't about giving false readings or being invisible (though that's the ultimate goal when designing for it.) It's about minimizing the range at which radar and laser work at all. The C5 described above has been found to have effective radar distances of around half that of a typical car.

The radiator is angled, the black paint isn't reflective and contains no metal, the body panels contain no metal, the lights are hidden (C5) or small (C6), the car is short, etc. Radar and laser from the front have significantly reduced ranges on both the C5 and C6, especially with black paint and no front plate.

 

i'm only asking for an additional 10 - 12 mph over the 10 they already give us. if i can get the return to be around 10 mph lower than actual, it would be nice. i'm not running a front plate so if they are sitting on the side of the road and i cruise by i'm looking to see if i can make it so i only have to worry about them from tagging from the rear.

heading down to daytona in a few weeks.

-zig

btw: the lights question is an attemt to make my plates accurate. lmb f55 6-speed. va. vanish-d

 

Written in ALL Corvettes Are Red

 

cosine error doesn't require that big an angle. Beat a laser ticket once because the cop was too far off to the side of the road when he "shot" me.

 

Zig-
Reduced radar signature will not give a lower speed reading on police radar, it simply means that you must be closer to the police car for them to get a reading.

If you drive a big car toward the police car with radar operating, they will get no reading at all until you are (for example) 1/2 mile away. Then their unit will suddenly display your speed. The same thing will happen with a Corvette, except you will need to be closer before they get a reading. But that's still a good deal!

 

The near field of the radar's transmitted signal stays almost equal to the cross section of the radar guns antenna and will remain that way for several miles. Therefore meaning that the car size may have little to do with it only in that the eye of the cop to point properly at too small an object. Also the radar doesn't need metal to work properly. You might see that when you go to a baseball game and they clock the ball. It's the amount of energy that gets returned and if it meets the theshold bingo your had.

 

Well let me just give you a little information concerning some of the fallacies mentioned earlier in saying that your speed will not be detected from the side and is only available with doppler from a front or rear target. This is absolutely wrong. How do you explain a plane being tracked as it travels perpendicular to the antenna? With Doppler you get a phase shift versus a time difference that older type radars previously used. Now it is possible for a plane flying tangental to an antenna to appear as a stationary object and thus appear as a non moving target but then again they have something called frequency diversity to cover this problem. For those who want to know what frequency diversity ask me sometimes but in layman terms it is using different PRFs of a frequency. This eliminates blind speeds which was mentioned earlier about an Aircraft flying tangental to a rotating antenna. And since this car is moving sideways in comparison or else in a straight line this would thus change the wavelength of the return and thus change the phase compared to the known reference. If any of you want to read up on RADAR you can read a book by Merril Skolnik. He is considered to be one of the foremost authorities concerning RADAR. Anyway, back to the subject at hand. Good luck in whatever you are trying to achieve.

 

I have been a cop for 18 years. I have worked all bands of Radar, as well as Lidar. I am always amused at these discussions. In the real world I can get a reading locked on a Vette just as easy as on any other car. Even the smallest and stealthiest car is plenty big enough to reflect the signal back. The first 7 degrees do not effect the speed reading by more than 1 MPH. After that its an exponential increase in the drivers favor, until it gives no speed reading at all.