could visible light be used to detect F-22 and other stealth fighters

[Lekgolo555]

Can visible light be used to detect F-22 and stealth fighters at long range?

 

Can visible light be used like a radar?

 

Or what about other wavelengths like microwaves or Xrays? Can they be used in radar-like devices?

[Martin]

 

Can visible light be used like a radar?

...

 

it is a good question to ask---what wavelengths can be used

what are the tradeoffs?

 

visible light is blocked by cloud and fog

also there is often a lot of noise (other sources of light)

that makes it more difficult to filter out the particular visible wavelength that you are using as probe

 

I can't give a thorough answer to your question.

You ask about microwave, and I thought that a lot of radar WAS microwave already.

Maybe some other folks here can reply in more detail

[insane_alien]

have a look at LADAR(or is it LIDAR, i can't remember) its a radar system that uses lasers for detecting objects rather than radio/micro waves.

 

There is some interest in terahertz radiation (a fuzzy bit between high microwaves and far infrared.) that could maybe be usedonce its developed further.

[Cap'n Refsmmat]

LIDAR.

 

The problem is as Martin said - there's a lot of interference, and I'm guessing it would be impractical. In fact, the planes wouldn't even need to change their countermeasures - chaff would confuse the LIDAR as much as the radar.

[soultech]

I unfortunatly don't know enough abot the techology that gives stealth bombers their cloack of invisibility but i'm sur its gust a radar frequnsy predicament. Im sure there are radar radiowave frequencies that can be exploted by even rival gov mon hussling to render the currently invisibile stelth a big white siting duck on the advanced radars puchesed buy enemy countries, don't dispare, a few men lost and the stealth aircraft manufacturers will higher stroke the prices upon the US goverment for mor research development and consequentially safer stelth aircraft for the USA gove, why should they build the ultimate??? money makes the world go around! cough up some mre billions and and you wont have to worrie about a light freekwentsee radar detection unit!

[Sisyphus]

The stealth comes in large part from the geometry of the fuselage, doesn't it? That, at least, wouldn't be changed no matter what frequency you're using.

[soultech]

Radar is a figure of speach that can be used for ages but there are all mame of detecton modes: eg electomagnetic resonasce!, quantum entanglegled cripto;ogy brings to mind all sorts of twating schemes. Futurther more why intefer with the entagleed forms of two particles? just guage the quantun grvitronic prsence to sort out what is what where is what and analogialy a stelth is a siting fluffy duck blabbering quak quak quak in response to its imediate demise for advanceted tech, quack quack to the designers who thing its imortal but its goose will be cooked imenantly, I do not BELIEVE that the stealth is un gottable, and its only a time fram od ten years when it becomes visible on futristic radar like a plane hager being aproched by an F-18 on a CFS-3 combat flight simulator computer game!

 

chris Rivos (Chris Rivers)

[JohnB]

Radar works by directing a beam towards the target and recieving the echo from the target. Stealth generally uses two different approaches to negate the radar.

 

One approach is the geometry of the aircraft, think the very angular F-117. The angles are such that the incoming beam is reflected anywhere but back to the transmitter.

 

The second line of defence is an absorbant coating. That's why they're black.

 

The big thing to remember is that Stealth aircraft are not invisible to radar, they have a very low radar cross section. Radar recieves echoes from just about everything around it, consequently radar units have discrimination programs that set a threshold for what the unit will consider "interesting".

 

The basic idea behind stealth is to reduce the radar cross section of the aircraft to below that threshold and therefore the radar no longer "sees" it. The downside of the geometry approach is that it works rather well from most sides but is much less efficient from above. The Jindalee Over-The Horizon (OTH) radar reportedly has little trouble finding and tracking "Stealth" aircraft. Information on JORN here.

 

One might be tempted to think that an improvement in the discrimination programs may help. IIRC however the radar cross section of the F-117 is about the size of a little fingernail. If your unit can see that it will pick up every moth and bird in it's range, making it useless.

 

I would think that visible light would be rather useless as a detection method. Any beam powerful enough to return a useable echo would almost certainly blind or burn the pilot. Great as a weapon, but you wouldn't know where to aim it.

 

TBH, the best defence against the curent generation of stealth aircraft (during daylight) is a bunch of people watching the sky armed with a selection of heat seeking missiles. The aircraft are subsonic and fly low which makes them vulnerable to heat seekers fired down on them from hill tops.

[soultech]

Unsure what jindarlee is but if its the aus ginderbin the stuff has extream probs at dusk and dawn. If we have a problem of plane angles reflecting away radar waves well theres more than one way to skin a stealth. know lets think about this. the plane must have a specific temparture that is diferant to the souonding atmospher. it must be refecting some sunlight from the sun in the direction of the radar system so i supose your right light can be used to detect stelth. The sonic wave wilst only at the speed of sound would cause ripples and turbulance in the atmosphe that may be detected by some wavelength of radar just as clouds, rain anelectrical stors can be detected. Pls continue, i shall when i think of something.

[John Cuthber]

The answer to the original question seems to be yes.

http://www.webrankinfo.com/english/seo-news/topic-5417.htm

Also, there are 2 things to note about the return radar signal reflected by an object, how big is it and how much is it Doppler shifted.

Birds and moths don't travel at the speed of sound so they can be discriminated from planes that do. This is complicated by the use of "chirped" radar pulses.

[JohnB]

Birds and moths don't travel at the speed of sound so they can be discriminated from planes that do.

Normally yes. The problem with ground based radar detecting stealth is the very tiny cross section. It's an image that winks in and out. It can be confused with birds, not one, but a flock. Apparently it's a cascade effect as the birds flap their wings. If you get the initial blip from the bird at the back first and then blips from the birds in front of it, it can appear to be one object travelling very quickly.

 

I probably haven't explained it well, but that's how a radar op explained it me some time ago. I would expect chirped pulses to somewhat cancel the effect, but I just don't know.

 

Soultech. There is normally no cloud turbulence from a stealth aircraft because they don't go up that high. (Usually.)

 

The standard attack profile is not to come in at 10,000 ft and blow the h*ll out of the target. You can only do that if the opposition doesn't have radar. Under normal mission parameters, you will come in at around 500 ft or less flying down every valley you can find. As radar can't see through hills this makes you hard to spot most of the time. For short periods though, you are a big bright blip. The idea for stealth is that when you should be a big, bright blip as you cross the valley, you aren't.

 

As you approach the target you will climb and accelerate releasing your payload around 5 clicks out. Then you turn around, head for the deck and run. The bombs will continue on a trajectory just like an artillery shell and impact around the target. Even if you're using "smart" bombs, the laser targetting is usually done by someone on the ground.

 

Please remember that stealth tech is not some sort of magic. They can be seen by radar, it's just they are much harder to see than a normal aircraft. They are generally slow with poor manouverability and in the case of the F-117 absolutely no way to fight back. If caught visually by a normal fighter, the F-117 is a big, fat, slow target. (And the B-2 isn't much better.) Give me a Hornet any day.

 

FYI.

The only recorded shoot down of a stealth aircraft was by the Serbian forces in 1999 using a SA-3 missile which was first deployed around 1964. A type of missile 30 years old shot one down.

[MrMongoose]

Isn't seeing a stealth bomber detecting it by using visible light?

[insane_alien]

yeah but usually once you see it it is already too late to do anything about it.

[Klaynos]

yeah but usually once you see it it is already too late to do anything about it.

 

binoculars...

[insane_alien]

binoculars...

 

guided missiles...

[MrMongoose]

Well nobody said the observer is the target... I might watch a stealth bomber taking off from america in the direction of England and phone the Queen to tell her.

[Klaynos]

guided missiles...

 

Visual targeted weapons... quite common. Laser guided bombs of course also use visible wavelengths...