Detecting Stealth Planes 409
Zurk writes " Newsweek said China's new Passive Coherent Location (PCL) system
tracked the signals of civilian radio and television broadcasts and picked up aircraft by analysing the minute turbulence their flight caused in the commercial wavelengths. cool huh ? " They hope to use it to detect the F-117A and potentially the F-22. Very cool use of technology to fix a problem.
heh .... technology always wins ..... (Score:2)
OH NO (Score:2)
Cannot be jammed? (Score:3)
Why can't a series of unmanned rockets leaving turbulence all around jam this?
Another issue: if you are following the trail, how good is your fix on its current location? If it was in straight-line flight, OK. But if it was in defensive maneuvers?
Hmmm...how well does it work in different weather conditions?
There are a lot of questions here. Sure it is a cute step, but this is not the final solution and the race will continue.
Cheers,
Ben
Stealth planes propaganda? (Score:1)
Commercial Broadcasts = No Expensive Transmitters (Score:1)
Anyone know if this requires extremely sensitive and expensive antennas? Or is the hard problem really one of extracting the "signal" from the noise. It seems to be the latter on the face of it. The idea seems to be to study the patterns in what would ordinarily be considered noise to localize atmospheric disturbances.
Could we really have a GNUAircraftTracker running a-la SETI@Home?
Hard to hide a plane, it is (Score:3)
I believe it's the Typhoon class submarines you can detect by listening for silence in the waters. The submarine is so ``stealthy'' that it's more silent than the water that surrounds it. Blammo!
I would have thought that satellites would have been the first to be used to track stealth aircraft. If you track how the earth reflects a radio signal (radar), and then suddenly something breaks the usual reflection (a stealth plane will break the reflection, but it will not reflect much back itself) you know where to aim.
Isn't it just fantastic what can be done with technology today
looking around... (Score:3)
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Here's an idea. (Score:1)
Or perhpas, could the U.S. put a transmitter in orbit and flood the air waves over China with bogus signals that have bogus torbulences that show bogus stealths.
It seem that this type of technology would be easy to counteract.
Stealth Tecnology (Score:1)
Re:Cannot be jammed? - the solution (Score:1)
This is almost funny !
Re:Cannot be jammed? (Score:2)
This would probably work against any kind of aircraft detection. There's a few problems with it that I can see. The enemy knows that something is out there, even if they don't know which target is the real one. They may then be able to determine which is the real target by its size. The unmanned rockets have to be computer-controlled to fly around in a reasonable manner so they're not obviously decoys. If they only travel in a straight line at a constant speed, and the enemy can determine their speed, position, and trajectory, they can easily determine where they were fired from.
Sounds like FUD to me (Score:1)
I've been seeing alot of China fears coming from the press of late.
For one thing, just becase someone has a new technology there is no telling how long it will be until it works. Look at the B-1B and it's advanced defensive/Offensive electronic packages...are they operational yet? I don't think they ever reached the promised level of operation.
Saying this new technology might work against the F-22 is simply conjecture. The F-22, when operational in FY-03 will be 14 years newer than the newest F-117A. Plus the F-22 does not rely just on stealth like the F-117 does. The F-22 has an extremly robust powerplant and radar system. The F-22 can cruse about 10,000 feet higher than the F-15, at a higher speed making it much harder for SAMs to intercept the aircraft.
This isn't quite so new (Score:2)
Turns out that the shapes these planes were built to, which gives them their low radar profile, was very bad aerodynamically (in the sense that it caused a lot more turbulence than traditional planes would) which in turn enabled this radar to locate the turbulence. Not sure what happened to this project since, but the idea of tracking stealth planes by the turbulence they cause, is nothing new
Fair use? (Score:2)
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Ian Peters
you only need to find the general location (Score:1)
Re:Cannot be jammed? (Score:1)
Re:Stealth planes propaganda? (Score:1)
As an aside, the F117a was designed with minimal help from computers, which is why it's mostly flat surfaces. The B2, all the calculations were aided with powerful computer technology, allowing the designers to create a plane with not a single flat surface. It also gave them more room to play with aerodynamics, making it also more stable in flight than the F117.
Man's unique agony as a species consists in his perpetual conflict between the desire to stand out and the need to blend in.
Anti-Chinese sentiment should not cloud opinion (Score:3)
Now if the Chi-Coms have invented and put into practice this technology, it only means we need to find a way to circumvent it. Say, by bombing TV and radio stations first.
Really folks, we have bigger problems to worry about. You know, the Chinese has the first compass. They kept it in a room and never used it until Marco Polo showed up with his. They pulled it out and said, so what?
Don't forget it was a Russian scientist who invented Stealth. He published a paper that inspired our development of the prototype.
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Re:heh .... technology always wins ..... (Score:3)
On the other hand, the fact that this technology can only detect the disturbance in the air opens possibilities. Decoys look just the same as real aircraft to the turbulence detectors, and if they're cheaper than AA missiles you can make it too expensive to shoot at things. Another possibility is transmitter technology which can fake the signature of turbulence trails, causing the enemy to "see" aircraft which aren't there. As long as you make them overlook the ones that are there, it doesn't matter much does it?
This also has counter-counter-offensive possibilities for cruise missiles. Cruise missiles are hard to see because they're so small and fly low, but the effects they have on broadcast-band radiation can be seen nonetheless. On the other hand, using the same radiation signatures any aircraft scrambled to intercept the missile can be detected by the offense and the missile signalled to evade them. Missiles (or decoys) which get shot down mark the locations of AA guns which can be avoided by the rest. It's all one big game of one-upmanship, and since the USA already has a system like this proposed for air traffic control (talk about civilian conversion of military technologies!), you can bet that our side has some way to deal with the military issues already under development.
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Aurora? High speed pulse jet. Does it exist? (Score:2)
Silent Sentry (Score:3)
Re:Stealth planes propaganda? (Score:1)
A Stinger won't guide to a bumblebee, not because the bumblebee is so small, but because it's barely warmer than the air. Stingers are infrared-guided missiles, not radar. If you heated the bumblebee up to red heat, you could probably hit it with a Stinger.
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Re:F117 (Score:1)
2. Normal fighters do tend to crash on a regular basis, esp one engire fighters like the F-16 or A-7. Take a look at crashes of fighter types for every 100,000 hours and notice that single engine fighters crash about twice as much.
3. The single F-117A lost in Serbia was lost (pbly) to a SAM that locked on during the bomb run while the weapons bay was open and thus the aircraft was unstealthy. Or it was lost to a combination of SAM and airborne radar illumination coupled with optical sights. It was a full moon on the night the F-117 was lost.
For more on the F-117/F-22 go out and find World Air Power Volume 19 and 38.
Re:Commercial Broadcasts = No Expensive Transmitte (Score:1)
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Re:Stealth planes propaganda? (Score:1)
Re:OH NO (Score:1)
Does it really matter who invades? honestly? If someone did invade you wouldn't only have the national guard but you would also have citizens with hunting/assult weapons attaching The ground troops. Also inorder to invade you need to have an extremely strong navy and from what I understand china doesn't have the navy that we have. So for now I think were safe.
If you really want to know who is more powerful check out Janes I'm sure they have their listings.
cheers,
Mike
Why this won't work? (Score:2)
Holy flying monkey love batman! (Score:1)
Does this mean they'll be able to detect me flying over China even when I'm wearing my composite spandex Robin outfit? Dammit! I new my sexy curves would be the end of me! Why couldn't I just be flat like Bob's Mom?
Re:OH NO (Score:1)
It won't matter if they can detect the planes, anyway. They're scavenging good aircraft just to get spare parts now... there may not be many good aircraft for the next engagement.
This is NOT the same. (Score:2)
However, this development is not an end game by any means. I have little doubt that the US will come up with ways to circumvent it. What is really troublesome for the military, I suspect, is that it could probably be implimented by 3rd world countries which otherwise don't have the resources for such defense mechanisms.
...I personally feel that stealth is a bad way to play the game. Cheaper unmanned vehicles is far better....fly more, who cares if they shoot a few down....
Re:you only need to find the general location (Score:1)
Finding the plane precisely is important because you have to launch a missile well before it gets to you so that the plane essentially runs into the missle, since no missile can actually Catch one.
Oh, and there's no such thing as a 'stealth fighter'.
Dreamweaver
Re:Aurora? High speed pulse jet. Does it exist? (Score:1)
cheers,
Mike
Re:you only need to find the general location (Score:1)
Does a stealth fighter actually have a cannon ?
AFAIK, it doesn't, meaning it shouldn't even try to enter a dogfight.
Re:you only need to find the general location (Score:1)
It's pretty spiffy (Score:1)
spy planes would be shot down if flown over the
U.S... well, it's nice to know that the converse
is true.. Personally, I got a good chuckle when
the USSR shot down a spy plane back in the 80s
Nope, not FUD (Score:2)
Also, apparently the low tech low resolution long wavelength radars still in service by Russia and their customers, who can't afford the snazzy new short wavelength radars in use by NATO, are better at detecting stealth planes than those snazzy new radars. I gather the US tried to downplay this, out of embarrassment and cover-your-ass syndrome.
And another tack is mumble-mumble radar, where the transmitter and receiver are far apart. Stealth planes are stealthy not just from absorbing the radar energy, but also from directing radar energy away from the straight return path. Those non-normal directions get more than their share of the reflection -- put a transmitter ahead of the plane and separate receivers on the side, and the side receivers get a better return from the stealth plane than forward receivers get from a non-stealth plane. Or something like that.
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Re:F117 (Score:1)
Re:Sounds like FUD to me (Score:1)
One of the F-22's key selling points is its ability to supercruise (fly at supersonic speeds WITHOUT the use of afterburners). This results in higher speeds, with a lower IR signature, and will make it not only harder to track, but harder to hit with IR-guided SAMs.
People seem to think that the F117A was designed to be a "fighter" in the same sense of the F-16. The F117A would be taken down easily in a "dogfight". It just wasn't designed for that. And the F22 is not designed to be a "stealth fighter" in the same vein as the F117A. Its stealth technologies only *augment* its excellent maneuverability, powerplant, and weapons capabilities.
/. doesn't usually have military discussions, but I'd love to hear what people think about Congress' lack of F22 support, and also a discussion on JSF.
Re:Stealth -- not (Score:1)
- I thought that was just a function of the material they made it out of - course they could have painted it that blotchy infra-red absorbent grey like the rest of the US airforce.....
or did Lockheed suddenly get taken over by Henry "you can have it any color you want as long as it's black" Ford ?
Re:Cannot be jammed? (Score:1)
Re:Commercial Broadcasts = No Expensive Transmitte (Score:1)
This is incorrect (Score:1)
This kind of turbulence refers to the radio frequency spectrum.
Re:Hard to hide a plane, it is (Score:1)
cheers,
Mike
Re:It's pretty spiffy (Score:1)
Re:you only need to find the general location (Score:1)
Re:Commercial Broadcasts = No Expensive Transmitte (Score:1)
If that's all it takes to do the reception and analysis, then connectivity is the only other hurdle. When everyone has T1 equivalent connectivity at home, I'll bet that distributed.net will have competition from distributed.track.
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Likely misconceptions (Score:2)
My take on what the technology actually is.
When watching broadcast TV with a crappy antenna, a plane flying overhead will disrupt the signal. An array ground based antennas can determine the exact pattern of the disruption, and with calibration, determine the size and position of the object causing that disruption. Since the goal isn't to watch TV, the detectors can be made much more sensitive to small disruptions.
The best weather to fly in to avoid this sort of detection would be a thunderstorm (but hard on the planes and pilots).
Such a system is not likely to have the precision of conventional radar, ind is more likely to mistake one target for another (I base that on the longer wavelength of commercial broadcasts).
Final critique, it's a very creative idea!
Re:Stealth planes propaganda? - Yes.. (Score:1)
There will be a lot of things that the radar picks up that are larger than bumble bee, maybe thousands, but which ones are moving at more than 500mph?
Re:Stealth -- not (Score:1)
cheers,
Mike
Re:you only need to find the general location (Score:1)
Dreamweaver
Wild Weasels (Score:1)
'Wild Weasels' are A4 pilots on anti-SAM duty. They draw SAM radar and fire AMRAMs to blow them up. This scares the bejeesus out of SAM operators who will then only illuminate targets for a quick moment.
The scary thing about this technology is not that it can be used against stealth aircraft, but that it doesn't transmit, and therefore cannot be countered by Wild Weasel tactics.
Lockheed Selling Similar System (Score:1)
Re:Stealth planes propaganda? (Score:2)
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Re:Here's an idea. (Score:1)
appear as though there were stealh bombers all over the place?
Only if they want the Chinese to bomb Hawaii and Alaska in response.
Re:looking around... (Score:2)
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who cares? (Score:1)
let's see, the US chucks a skyburst of a bio-genetic bomb over beijing, wiping out the population, leaving people writhing in agony as blood spurts from their various orifices.
of course, China will chuck a skyburst of a bio-genetic bomb over Los Angeles, wiping out the population, leaving people writhing in agony as blood spurts from their various orifices.
what fun! and all because the USA tends towards laisez faire capitalism, which has a unfortunate side effect of homelessness and a disparate stratification of the classes (high, low, and the big lie).
what fun! and all because China insures it's people have the bare essentials to survive (except for that 5% that live obscenely high on the hog), and refuses to let anyone criticize that system (unless they want to go to jail, a mental hospital, or be executed).
what fun! both sides view the other as evil. oh well, maybe the death agony will be short. or somehow the two side can compromise? will china get free speech and elections? will the US increase human rights and respect for all people?
Re:Cool thing? (Score:1)
I would suggest you think long and hard about the relative merits of the world we live in today vs. a world in which China outpaces the US as a world superpower. There is a reason Canada can have a huge undefended border with the US. Take a look at China's neighbours... an undefended border didn't turn out so well for Tibet. China routinely reiterates its threats to invade Taiwan.
What about proliferation of nuclear and missile technologies? The US has been a strong advocate of non-proliferation (recent CTBT rejection notwithstanding) in these areas. Compare this to China's record on proliferation: They have provided aid to the weapons of mass detruction and/or missile programs of Pakistan, Iran, Saudi Arabia, Syria, Iraq, Libya, South Africa, India, Argentina, Algeria, and North Korea.
I really sorry that you are bothered so much by "the US thinking they're all that and a bag of chips", so much so that you believe you can rationalize a second Cold War on that basis. The reason you can voice your opinion on this forum from the comfort of a free country is not the 70,000+ underequipped Candaian troops stationed here, it's the security guarrantees from our friends in the US, from our benevolent juggernaut neighbour. Get your head checked boy.
If I wanted to disrupt the US military... (Score:1)
Any bad guy that manages to take out the GPS satellite constellation in some will take away a capability that our armed forces put to very good use.
Re:Awesome! (Score:1)
Hmmm, I don't think going to college really has a terrible lot to do with it. I mean the most evil tyrannical dictator in the history of the world second only to Hitler, Bill Gates, dropped out of college and is sadly one of the most powerful men alive today, and the richest.
Nikola Tesla went to college, where he was told by his professor that a brushless electric motor was "impossible". In fact just about everything he invented defied what college professors thought at the time to be true.
Albert Einstein often cut class to study physics on his own, he went on to become the most famous scientist of all time.
I am by no means saying that a college education is a bad thing. But just because someone isn't a college graduate doesn't make them dumb, and just because someone is a college graduate doesn't mean they are smart.
I believe the saying is "It's sad that having a science degree doesn't make one a scientist."
Re:Wild Weasels (Score:1)
Wild Weasels are not "A4" pilots. Wild Weasel duty has been flown by different types of planes in the US arsenal-most recently the F-4G Phantom(which is purpose built for this duty), and F-16s. F-4G has been used in the Gulf War, but I don't think it's still in use as a Wild Weasel aircraft.
It is true that radar operators are scared and illuminate targets for a short time, fire their missiles and turn the radar off. While this seems to be an extremely dumb idea, not all SAMs rely on radar guidance throughout the flight, and Iraqis scored on numerous US and Allied aircraft using this method in the Gulf War.
The primary anti-radar missile in use by the US now is called HARM, not "AMRAM". AIM-120 AMRAAM is a different beast, a BVR(beyond visual range) medium-range air-to-air missile. HARM was used in the Gulf War, and most recently HARMs were quite useful in reducing rabid Milosevic's air defense radars to scrap metal.
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A site for everything Bluetooth. Coming in January 2000.
Re:Stealth planes propaganda? - Yes.. (Score:1)
And there's a huge difference between DETECTING raindrops and TRACKING raindrops. I HIGHLY doubt even a SPY-1x will TRACK raindrops.
rivit-joint. (Score:1)
China already show stealth on, uh, normal? radar (Score:1)
Stealth and Radar (Score:2)
Re:Fair use? (Score:2)
anyway, here a suggestion - how bout
Re:Stealth Tecnology (Score:5)
Plus, you don't want everyone on the fair grounds to learn about the capabilities of the plane. If you're interested in the topic, just compare the cockpit photos of the Mig-29 demonstrated to the West in 1989, and Mig-29s in actual service with the Russian Air Force. You will be amazed to see how they dumbed down the cockpit layout so that the first Western smart-ass to see the photos would say "Gee, Russians are using 1950s technology in these."
It is amazing how this little known security feature causes people to downplay the capabilities of these aircraft. I remember back when a bunch of F-117s came to Turkey; the armed forces and civilian air traffic control boasted how they could easily detect the so-called "stealth" fighters. As the Iraqi and Serbian can tell, it is not that easy without the fittings.
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Re:you only need to find the general location (Score:2)
Paul
Logistics (Score:5)
First you send in infiltrators, who set up airstrips in remote locations, and purchase ammunition. They purchase vehicles and fuel. You then take about two dozen chartered commercial jet airlines, you load them with troops and land them at US airports all friendly like, most likely the east coast. It doesnt take long for 500 or so armed troops to capture an airport, and then fortify their position quickly. The 747's can carry anti-tank/heavy weaponary, and plenty of ammunition. No food, cause that isnt neccessary. These troops are the first wave and will only be the front line for a short period. 10-20 minutes behind these 747's, are standard long range cargo planes, carrying light armor vehicles and more troops, these land at the commercial airports and at the private airstrips you have set up.
Your troops take the LAU's and go like hell towards your assigned targets. Airbases, Army Bases, Naval Bases, Police Stations, Gun Stores.
The trick is to move fast and capture quickly. A night attack on a weekend would be best, as you would capture quite afew bases relatively lightly manned and vulnerable, you might even bring pilots/tankers/sailors with you to take the captured vechiles and add to the chaos. You continue to bring in troops from china by air and land them at your secured areas.
At this stage it gets sticky. Your main mode of transport of large armor and troops is by sea. Getting by SOSUS is quite hard, and you have to deal with naval assests in the pacific. Hopefully you would attack at a time when a carrier isnt present close by in the pacific. You have to get your tanks in, so one way would be by using normal car carriers, who are on scheduled runs to make landfall on the same day as your attack to deliver vehicles. If you were serious about your plan, you might even nuke pearl/guam in the first 24 hours of your attack, to make it easier to move more heavy units from china to the US. This would also allow you to move a chinese carrier closer to the US to provide air support for the grunts and eventually transferring all aircraft to captured US runways.
You have to link up your heavy armor, light armor and infantry to push inland, obviously after securing your captured cities. You then utilise these cities, and the railroads to supply food and munitions to your front lines as they spread inland. Time elapsed is about 48-72 hours, more then enough time for the US army to mobilise and to present a good front line, possibly near the rockies.
Attack of the US is not an easy task, and requires exquisite timing of delivery of assets. It requires china to send troops a huge distance, and to get past pearl with ships. It would obviously be easier to attack with an allie close by, say from cuba or south america, to attack other borders at the same time. This draws units away from your main assault.
Now this is a possible scenario, if, china had the logistical assets to do this. The Chinese army is much like the soviet army used to be. A large club to bludgeon your opponent to death with numbers, aslong as he is relatively close. China has never had to move huge amounts of troops over an entire ocean to attack an enemy so far from home. It isnt easy logistically. But possible. To make it more interesting, an enemy may even release chemical/biological weapons before he attacks. He may poison water supplies. He may release anthrax or similar diseases. He may sabotage power stations, he may cause an increase in terrorism before hand.
There are alot of things in warfares bag-o-dirty tricks.
As for disabling the US nuclear counter attack, that is a tough nut to crack, and would require unconventional techniques im sure. For example purchasing properties near known ICBM silos, buying a few hundred stingers and praying you can cripple a few missles before they hit your country. Perhaps small backpack nukes could be used to crack the silos at close range, but thats debatable, as those silos are hardened and quite well built. Maybe wait till they open up to launch? Who knows.
Naval nukes are even harder to disable apart from an intense naval campaign by your forces to kill the subs, even then, they can launch from almost anywhere, and damn but their quiet.
Carrier based nukes are also a concern. It is unlikely you would attack the US without first developing a good ABM defence.
So in answer to your comment
'It would be exceedingly difficult to come anywhere near the US shore with any kind of sizable force.'
True, but not impossible. Give war a chance!:)
Re:Why this won't work? (Score:2)
Yes, and most fighters and bombers have this... It's called ECM, for Electronic CounterMeasures. However, the stealth planes (F-117A and B-2) have NO transmitters of any kind (other than std radio, which is kept totally silent during missions.) so they don't get an ECM pod. Broadcasting over every wavelength kind of defeats the purpose of being stealthy. For most fighers/bombers, this is fine though.
Most people misunderstand the main purpose of stealth aircraft. They are not stealthy to prevent them from being hit, but rather to not let the enemy know that they're there in the first place. They are meant to quietly sneak in, bomb the crap out of comething, then leave. The whole selling point of the F-117A was "They won't know you're there until they're dead."
Re:OH NO (Score:2)
Not. China has manpower, but you are overlooking the fact that China is on a whole other continent than the US.. There is litle pond called the Pacific Ocean between the two continents, and crossing that would be damn hard. Try to fly and you will get shot down. Most ships would be sank by mines, submarines and planes. Preparing a large scale invasion will take several months, so it is not like they can suprise you. And even if the Chinese army was somehow able to get foothold in the US, they could never hold it because even a 10 million man army is no match to 70 million angry, armed civilians who are protecting their homes. But of cource, this question is totally academic as China would never even consider attacking, as long as the US still has nuclear weapons.
I don't think Americans are stupid, but if there is one thing I don't understand about you people, it is the paranoia that everyone is out to get you. "We are the best and most influential nation, so everyone wants us dead", "Every person who is not a US citisen is a potential enemy", "The Amerincan way of life/American dream/American whatever is at dander", and so forth... I guess it's the legacy of cold war or something..
Getting really offtopic here..
Re:OH NO (Score:2)
Assuming China still has good relations with Russia, and they could work out some sort of deal, they could send ground troops across the Bering Strait. I'm sure Canadian ground troops wouldn't stand a chance.
Re:Stealth is a write-off (Score:2)
Re:Commercial Broadcasts = No Expensive Transmitte (Score:2)
I live near a large flock of ravens (corvid family - about 150 of them). They fly over at predictable times at between 30 and 120 feet. I'd calibrate the kit against them first. Calibrating the setup, and keeping it calibrated, would be the headache.
If I could detect the ravens, then I'd ask the US military for a stealth plane to play with. This is where the 'hobbyist' bit is limiting.
I suspect there would be major problems in a populated area with transmissions from electric motors, microwave ovens, mobile phones, overhead lines and all the other bits of electromagnetic technology we rely on. I'd give it a go if I had the time, though.
Typhoon class boats (OT) (Score:5)
"the typhoon is huge"
Right. The largest military sub to see active duty.
"it is nuclear powered rather than desal (sp) powered"
Wrong. The Typhoon boats are nuclear, diesel, and battery powered. Why do you think they were so darned big? The reactor put out enough juice for a city. If that failed, there were two mammoth diesel engines. By mammoth, I mean 12'x10'x6', 10,000+ hp, and enough tourque to drive the boat through the water at 20 knots. Should those fail, there were two large banks of dry cell batteries on either bow. The batteries served three purposes:
"I don't think the largest sub in the world is more silent than the water around it."
Wrong. Here's an example: Let's say that there is a skyscraper in the middle of a field (just follow me on this). Now let's say that the wind is blowing out of the North. Let's also say that you are blind, and walking past the south side of the building (going East to West). There will be a point when the building will start to block out the wind. Logic will tell you that it's no longer windy, and it's also very quiet. You may then deduce that there is a building to your right. Here's a diagram:
**********************
**********************
.........--------*****
.........||||||||*****
.........||||||||*****
....o....||||||||*****
.........||||||||*****
.........||||||||*****
.........--------*****
**********************
**********************
Legend:
* = wind;
-,| = building;
o = you;
. = calm air;
Now, relate that to being in a sub. Since there is always ambient noise in the ocean, the trick is to find someplace where there isn't enough noise. That'll be a Typhoon (or maybe a Charlie) with her plant cut way back. If you know where you are and how fast you're going, you can figure a bearing on the Typhoon. Once you have that, you can use basic trig to figure out range, speed, and mark, in that order. After that, it's simple to sneak up and fire your torps and get back out.
zantispam (who gets waaaaaaaay to into this stuff)
Jedi Hacker (Apprentice) and Code Poet
This is getting silly (Score:2)
Even so, you would NOT want to send troops over the Bering strait. Why not? Terrain! Go look at a map, count mountain ranges. That is *not* territory through which you want to maintain an overland supply train.
No, the idea of China invading the US any time soon is sheer idiocy. They are far better advised to just wait. The US today is the largest debtor nation in the world, and it has held that title for over a decade. The current economic boom is hiding it, but eventually the markets will wake up to the fundamental economic reality, and in due course of time military might will follow the money.
The days of the US single-handedly dominating the planet are numbered, and the Chinese leadership knows it. This is not to say that the US will be toothless any time soon. But, like the British Empire before it, the Spanish empire before that, and so on through history, economics is catching up to current World Superpower.
Of course the realization of this status may take a while. Look at the British Empire. Between WW I and WW II the stage was set for its collapse. WW II demonstrated that it would not last, and the years following saw Britain quickly losing its territory. Yet the British public didn't realize this for decades after. They even went to war defending a corner of the Empire as late as the 1980s, and we still have as a last cultural hurrah the James Bond movies...
Cheers,
Ben
Re:Logistics (Score:2)
Here's more thoughts:
Maybe nukes would be good. Think Maskrovia in _Red_Storm_Rising_ You set off your nukes at very discreet, tactical targets. Make sure, however, to nuke one large city in a very messy way. The US responds, and you make sure that, while some of your cities are being taken out, you nuke, say, Kiev. Now the Russians are in on it, and you have support.
Of course, this scenario ignores the fact that your country is a glowing hole in the ground...
My other thought revolves around guerrela warfare. If you get enough nationals in the country in the 6-12 months prior to commencement of hostilities, you may be able to set up enough of an infrastructure to paralyze the US for 72 hours. That would be more than enough to push to Washington and sue for peace (following your "East-Coast Scenario").
Jedi Hacker (Apprentice) and Code Poet
Covert Espionage (Score:3)
Russian Stealth (Score:2)
In general, everything I've heard, which has been common knowledge in the west, has been that the MiG fighters have a very good reputation for engineering. In particular, westerners seem amazed (I was amazed, for one) to learn that the MiGs are not fly-by-wire and are still very easy to fly.
Seems like propoganda... (Score:2)
Honestly, this isn't all that much of a surprise for a number of reasons. The article goes very lightly on Lockheed Martin's Silent Sentry system which we've had for years. So much, in fact, that the way that it works isn't even classified anymore.
Furthermore, it seems that the by using commercial broadcasts you're risking a lot. Turn on your TV with just an antenna. Even use a really powerful antenna. Unless you're right by your local TV station, you're out of luck. The picture will get scrambled from interfereance over space by the uneven random distrubance of everything from atmosphereic/pressure differences to object's in it's path. So unless you had a vaccum and a perfect signal between all your recieving antennas (as has been pointed out you'd need at leat 3 to get a 3D reading, although more would be helpful.), you'll have some interference and turbulance. Furthermore, radio signals in places like China are less likely to be reliable than in more developed countries.
Also remember that we've had this technology for a number of years. We haven't widely deployed it dispite the fact that it's cheaper to do so than most conventional radars. Believe me, the military likes *NEW* toys more than they like *EXPENSIVE* toys. And this would be a new toy. It evedeintly isn't that reliable, unless the Chinese have managed to leapfrog us in this.
Also it's been pointed out that you can just start taking out TV/radio stations. The silence would be deadly if this was your only air defense. You could also theoretically do such things as rotate the plane every now and then to change the way that it disturbs the air. By traveling at different directions to the wind and at different angles and wind patterns, you'll change the turbulance that you create. Also remember that air craft (with the exception of ones like the F-117, designed before we had good enough computers to effectively design a plane like the F-22) are *DESIGNED* to make as little disturbance as possible. Before it was just areodynamics, now it may be a possible way to be stealthy. Futhermore a system this sensative would also detect things such as low pressure zones, air disturbance created by such things as factories, etc. (especially in cities), and would probably be *MUCH* more prevalant than the signature left by a 20m aircraft.
next gen (Score:3)
you can detect it, but as soon as you figure out where it is, you cannot know where its going
Big deal (Score:2)
Re:Cannot be jammed? (Score:2)
Exactly. If this were anything more than glorified theory, you wouldn't be reading about it on Newsweek, of all places. The US didn't exactly run around trumpeting its sucesses to Time in the field of stealth technology when it was discovered decades ago.
--
"Some people say that I proved if you get a C average, you can end up being successful in life."
Re:looking around... (Score:2)
Even with the increased speed of planes today, a decently well trained, well dispersed program of ground observation could be quite useful against stealthy aircraft.
Doug
Re:Poverty in China (Score:2)
He said bare essentials. "In a first world sense" presumably includes a number of things one could ( and indeed prior to 1900 would ) live without ( for example, cars and electricity ). You are guilty of confusing "wealth" with "bare essentials"
Profoundly Bad Military Analysis (Score:2)
You then take about two dozen chartered commercial jet airlines, you load them with troops and land them at US airports all friendly like, most likely the east coast. It doesnt take long for 500 or so armed troops to capture an airport, and then fortify their position quickly.500? In most large cities, the police alone would outnumber and outgun them, let alone the national guard.
Your troops take the LAU's and go like hell towards your assigned targets. Airbases, Army Bases, Naval Bases, Police Stations, Gun Stores.
By this time a full scale military alert would already have been triggered, and Beijing would be glowing with the aid of a nearby submarine. Added to which, it would be trivial to block access routes and tie off the groups of troops. Your troops would be stranded, hunted, and eventually crushed with ease most likely by state police units alone, who would once again substantially outnumber and outgun your troops on the ground.
You have one basic flawed premise - the surprise attack. Most likely any hostilities between the two powers would be preceeded by months of posturing, during which time national defenses would be beefed up, airports made more secure, and submarines and bombers would be scouting their targets. Satellites would easily, easily detect any significant movement. Intelligence would likely be able to predict the movement with great accuracy.
I think you've watched Red Dawn too many times.
Re:you only need to find the general location (Score:2)
Sending any kind of bomber (which, frankly, the F117A really is) unescorted against fighters has always been suicide. Just because stealth doesn't change that doesn't mean stealth is useless, just that it isn't a shield of invincibility.
Re:OH NO (Score:2)
Our current troops are over committed, ill trained, and ill-equipped. What I said about aircraft parts is true enough, and I've likely understated the situation.
True about terrorism. Of course I don't agree with the way our Military is
Along that vein, the US has done more to secure the foothold of Communism in this century than Stalin. We've opposed anti-communisism as an ideal. We've sent huge amounts of money to countries that don't have our good will at heart. We've proped up inhumane gov'ts. And where we didn't outright support the "agririan reformers" we thwarted their adversaries or treated them so badly the Communists looked like heros.
Terrorism is a tricky issue. It is difficult to implement the steps needed to interdict terrorist activity without trampling the Constitution under jack-boots. At the same time, the US has sponsored its fair share of "terrorist" type black ops. There is a vengeful desire in some parts of the world that isn't entirely unjustified.
As for China, I don't forsee a full invasion. But they have entangled their tentacles way too far into the US. While we toute civil rights here, we're one of the largest (if not the largest) consumer of Chinese goods. We lease them our ports (displacing US Marines), we let them land the management leases of the locks at each end of the Panama Canal. Let them (illegally) contribute to our political processes... What's that saying about not buying the cow when you can get the milk for free?
Re:Aurora? High speed pulse jet. Does it exist? (Score:2)
The problem is, it was the code-name for the Lockheed Stealth Bomber prototype.
The Hypersonic plane which may, or may not exist, is still in the realms of model kits and "I saw something strange" stories.
There's also the TR-3 or Black Manta, which has much more evidence supporting it (a stealth recon / laser designation platform) including some actual videotape existing somewhere. More information in the rec.aviation.military faq (RAM is my current favorite newsgroup - WWII pilots, Vietnam Pilots, B-52 Pilots, SR-71 Pilots, and a permant floating flamewar RE: Yugoslavia/Russia/America)
Personally, The Aurora is a silly code name for a high-flying plane. Should be called something like Dwarven Cleric. Sure, it's not a very cool-sounding name, but if the codename leaks you'd have your enemy working on upgrading their seismology tech, while you fly over happily at Mach 8+ taking happy snaps
Re:Typhoon class boats (OT) (Score:5)
craw wrote: "What are the sources of ambient noise in the oceans?...I'm going to assume that you are talking about high frequency sources, given that you allude to blockage."
Actually, I was referring to flow noise. Flow noise occurs because, well, water flows. When trillions of molecules of water move and tumble and collide, they make noise. Depending on water speed, depth, and temperature, water can have all three frequency ranges...
craw wrote: "However, the propagation paths will be complicated due to the vertical sound speed structure and the variablity of this function. Note that rain and breaking wave sources will be broadly distributed (including those close to the sensor)."
Correct. This is complicated further by the position of the thermoclyne(sp?).
When water is of two contrasting temperatures, the cold water will sink and slow down. It forms a fairly flat `layer'. On top of this is the warmer water. Water on top of the layer tends to move faster and have more variety of currents. Therefore, detecting sound below the layer from above the layer is more difficult than detecting sound above the layer from below the layer. Since the layer sits at between 200 and 600 feet, it's easy to stay underneath it.
Now, if I'm 100 feet below the layer, and the Typhoon is 100 feet above the layer, and the chop is about 20 feet (think mid-Atlantic in fall), I will probably have a difficult time hearing her.
If the chop is closer to 5 feet, however, and all other factors are equal, I should be able to hear the Typhoon if I'm +- 3 degrees to either side of her (like this:
Below the layer, these factors are mitigated.
craw wrote: "If you are talking about low frequency signals, then the dominant source is shipping, earthquakes, and whales."
And flow noise (below the layer). Remember that the currents under the layer run at about 3 to 6 knots. These currents are not nearly as fickle as the currents above the layer, therefore, we can depend on them (a bit more).
craw wrote: "If natural fluctuation occur, then how do you differentiate betweeen natural fluctuations and the "silence" of a sub?"
If the current is coming from the East, and there's a Typhoon to my East, then depending upon the difference between our respective `altitude' (can't remamber the proper word) and distance between us, I may be able to detect her, either from an absence of flow noise, or because of a variance in what I'm expecting to hear. The point is that I should hear x amount of y different types of noise. If x is ever more than a standard deviation off, I have cause to investigate. More on this later.
Ozwald wrote: "When moving air hits a round object (or an object boing through air), it tries to go around and continue on its original path."
But is does not do this perfectly. See below...
Ozwald wrote: "Ever drive down a highway at 100 km/hour behind a truck/trailer? Being directly behind one causes your car to bounce side to side from the truck's turbulance until you finally get atleast beside the cab of the truck."
You have proven one of my points for me. (Keep in mind that Typhoons can't (and wouldn't) go 100 kph) Ok, when you're behind that semi, everything concerning the air is totally different than it would be if you were not behind that semi. Because it is there, and because it is causing a disturbance several meters behind itself (you don't tailgate, right
Another point: have you ever sat in the back of a pickup? If it's going slow, the air is calmer right next to the cab than it is by the tailgate (it's much easier to light a cigarette there). If you're looking for a sub that's going reeeeeealy slow (as boomers are want to do), they will leave `holes' in the water at those speeds. How big a hole is a function of the speed of the boat (I wish I could remember my trig - all two weeks of it before I dropped out. Thought I forgot, didn't you?).
Diagram:
***************************
***************************
************.**************
**********...**************
*******...../\*************
******.....|T |************
******.....|Y |************
******.....|P |************
******.....|H |************
******.....|O |************
******.....|O |************
******.....|N |************
******.....|__|************
******.........************
********......*************
**********..***************
***************************
Legend:
* = Flow Noise
. = Hole in the Water (quiet water)
Because of this hole in the water, the noise that reaches the sonar will be different for roughly that shape (as in the diagram above) for a certain distance at a certain speed yadda yadda ad nauseum.
Ozwald wrote: "A aerodynamic object like a plane, submarine, trout, etc. are designed not to cause turbulance from movement alone,"
Number one: They may not be designed to, but they do. Remeber that air is a liquid too, for the purpose of this exercise. Liquids have this nasty property called adhesion. Because all of the molecules of (water|air) are togeter in a finite space, moving one molecule will case it's neighbors to move. This is called drag. For a better explination of why this is a problem and possible solutions (for aircraft, anyway), look up the Laminar Flow wing here [exploratorium.edu] and here [nasa.gov]).
Ozwald wrote: "but it is impossible not to if it is maintaining a speed or accelerating."
Subs have to move. Kinda like sharks. Well, they dont have to, but they need to. Why? Three reasons (off the top of my head):
Therefore: Subs will never not move. Boomers will usually hold a really slow speed, but it's constant. Laminar flow problems and adhesion cause disturbances in the water, especially under the layer. And a really good sonarman can detect these disturbances.
*whew* I'm done now...
Jedi Hacker (Apprentice) and Code Poet
Re:Cannot be jammed? (Score:2)
Okay, so you broadcast noise at those
wavelenghs in the region in question.
If that doesn't drown out the effect of
the planes flying around, then I'm an emu.
This is of course, assuming that Newsweek did their homework , which may likely be an incorrect assumption. (Newsweek fscking up a tech story? Nah...)
Re:Anti-Chinese sentiment should not cloud opinion (Score:2)
The Panama canal story is so old and worn out that I wonder why you bother with it. Hutchison Whampoa, the manager of the ports at the either end of the canal, is a publicly traded company (on the Hong Kong stock exchange). Want to be a part of the Great Chinese Conspiracy to control "our" canal? Reach into your bank account and buy a few shares.
Export of cryptography is a joke. Please don't get me started on this one.
Returning to the main topic (the detection of stealth aircraft), about eight years ago I was talking with a friend about techniques for detecting a stealthy aircraft. While we were thinking of using a thermal sensor rather than using radio, the principle was the same, namely to look for atmospheric disturbances. While the technology to accomplish this is non-trivial, I sincerely doubt it would require access to classified data.
Is there Chinese espionage of American military and industrial data? Sure. And French espionage, and Japanese, and Israeli, and so on. As long as the United States has the world's most sophisticated trove of military technology, people will attempt to steal it. Occasionally they will succeed.
I feel that much of the attention/criticism which has been heaped on the Clinton administration is somewhat unwarranted. More than anything, Chinese espionage techniques have become much more sophisticated in the last 10 years, and China has made acquisition of military technology a much higher priority.
If you really need a domestic enemy who has been "selling us out" to the Chinese, perhaps you should look at Boeing, IBM, Sun, Lockheed, and the other champions of American business who have been scampering to sell goods, services, and technology in China. The Chinese are demanding technology transfer of one form or another as a requirment for entry to the PRC's domestic market. Any time the Congress or Clinton administration attempts to slow this process down (and no, it doesn't happen much), out come the lobbyists to explain to our elected officials the error of their ways. Don't kid yourself, Boeing contributes more money to both parties than any Buddhist monestary could ever hope to.
In summation, don't worry about the penny-ante sideshow that gets reported in the media. Keep your eye on who's REALLY giving away the store!
Jeremy Anderson
US develop Passive Coherent Location systems (Score:2)
Read more: at Lockheed Martin [lmco.com], about Silent Sentry [lmco.com], about a shuttle launch [nasa.gov] and about information dating back over a year [sightings.com] - this all comes very sudden and suprising to the US defense, completely new and previously unknown technology.
© Copyright 1999 Kristian Köhntopp
Re:Two Words (Score:2)
Perhaps the Chinese do not have the experience, but the invasion of Taiwan would be a matter of reaching ~80 miles for them, not really a projection, versus reaching ~7000 miles for the US. The Chinese would be able to use ground-based planes and helicopters to cross the strait, and small craft to sail it in a couple of hourse, while the US forces would be limited to carrier-based planes and heavy ships that would take about a week to arrive from San Diego.
Re:Profoundly Bad Military Analysis (Score:2)
Meanwhile, it would take days to call up the Guard, unless they had already been put into some sort of ready mode during the buildup of tensions. Same with getting the Army out there, since there are very few troops sitting around ready to fight here, the way they are, or at least were, in Germany. The invaders would very easily be able to take their targets. Holding them for very long might be another story, but that may not be necessary - they just have to impress the people of their vulnerability, and the inability of the government to protect them in order to crush the political will to resist, even if all the invaders are destroyed in the counter-attack. Kind of like the way the Vietcong Tet offensive convinced Americans that war could not be won, even though it was a disaster militarily.
Re:China invading the US (Score:2)
Of course, they'ed have to go through Canada prior to getting at us...
Re:Hmm (Score:2)
1980: 22.7% of federal budget outlays were Nat'l Defense.
1998: 16.2%.
Deal.
Source: OMB numbers, "Budget of the United States Government". FY 2000 (1999).
Re:Typhoon class boats (OT) (Score:2)
Your flow noise exists for flow around a solid body. Elsewhere, this "noise" would be extremely small. But suppose it did exist. Then what a sensor would pick up would be the noise from sources that were close by; remember, your noise source is omnipresent. Underwater acoustic attenuation is a combination of geometrical spreading and absorption loss. For high frequencies, this loss can be described by spherical spreading with the signal loss related to the distance, R. In this case the loss is R^2. IOW, local noise sources will dominate the signal received by the sensor.
There is something else, this noise source may be incoherent. But in this case, there will be noise cancelation by summing the signal received by the many elements of the receiving array. Result: no noise! But then, how would you hear a quiet zone?
Your last part of your comment describes flow noise past a solid object. In this case, your model is more appropriate for describing noise at the sensor, not the source.
You did get a whole bunch of karma for your comments!:-)
Re:Typhoon class boats (OT) (Score:2)
StarFace wrote: "You don't happen to be Tom Clancy incognito?"
I'm not Tom Clancy, but I play him on Slashdot.
craw wrote: " I suggest you read Wenz, Acoustic ambient noise in the ocean: spectra and sources"
I most definantly will. Thanks. BTW, I've never had any formal training for this. I appreciate you pointing out my mistakes.
craw wrote: "IOW, local noise sources will dominate the signal received by the sensor."
By local, do you mean 100 meters? 1,000 meters? 10,000 meters? If passive sonar can be effective at upwards of 50,000 meters (or greater when acoustical conditions are good), then local becomes kinda moot, I would think.
craw wrote: "Your last part of your comment describes flow noise past a solid object. In this case, your model is more appropriate for describing noise at the sensor, not the source."
Ok. However, there will be noise at the source. Analogy time. Let's say that you're in a completely empty warehouse. There is some ambient noise, either from air conditioning, or outside sources, or whatever. While some of the noise will be confused, there will be a fairly constant source of noise. We'll call that flow noise. Now, your friend walks silently up behind you (by silently, I mean that he doesn't make any movement to cause any noise that would be louder than the ambient `flow noise'). You would then notice the person, not because he was making noise, but because he was blocking noise and effectively becoming a hole in the air.
This is my personal experience. I have ultra-hyper sensitive ears. YMMV.
My point is that what you `hear' (or don't hear) is a result of a very slight change in timbre in the general flow noise. Because you hear something slightly different than what you expected to hear, you can detect your friend, even though he has made no noise whatsoever. In other words, he was too quiet.
And, if you took two steps to your left, you could triangulate a bearing because the change in the sound would remain localized to your friend.
Am I making any sense at this point?
SEAL wrote: "You can adjust your buoyancy any way you want. This is done with ballast tanks, of course.[...]Some boats can rapidly cycle water within special tanks. The idea here is to keep the sub level, since it is tough to perfectly adjust the different ballast tanks available on the boat."
Right. However, those adjustments cause...you guessed it: noise. What's a boomer driver's biggest worry? Noise. Since it's easier (and quieter) to maintain depth by going 2 or 3 knots, that's what they'll do.
I guess I should have said, "For all practical purposes, a sub (especially a boomer) will never not move."
Good point.
SEAL wrote: "A missile sub will stop when preparing to launch missiles"
At which point noise is a non-issue (klaxions, tube doors opening, blast of compressed air to shove the missle out of the tube, etc.). But, you are right.
SEAL wrote: "For example when running submerged, you get backpressure on your exhaust due to the water it has to push through (via the snorkel)."
I was under the impression that snorkels were only used when near the surface, when running the diesels for long periods (recharging the battery, reactor maintenace, etc.). When a boat is at (let's say) 100 meters, the exhaust goes out the rear. The exhaust can then act as propellant, and the backpressure is mitigated in the cavitation of the blades.
I might be completely wrong on this, of course.
SEAL wrote: "Oh yeah, and the diesel gives everything on the boat, especially your clothes, a quite unforgettable odor.
Can I assume you've served on a sub?
Jedi Hacker (Apprentice) and Code Poet
Re:Hmm (Score:2)
<laugh> Like I'd trust anything the Clinton News Network has to say about politics.
Re:replies to all, well most.... (Score:2)
I get the feeling that some of us here have no idea what the NRA is. The NRA is a public policy group like the EFF, they're not a paramilitary organization.
Second, you don't know too much about armament. A 50 caliber rifle can penetrate light and many medium armored vehicles. I would like to save up the 2k needed to buy one, but several people already own them. I would hate to be in an APC while someone is shooting a 50 caliber at it. One lucky shot would fill the inside of that APC with a shower of fast moving HOT metal.
Even 5.56mm Nato is a caliber that has decent ballistics for armor penetration. Especially if you're using the green tip Nato AP rounds.
Even less sohpisticated tanks can be disabled by a 50 caliber round. One shot down the barrel can render a tank's big gun useless. Would you be willing to get out try to use a machinegun against a person whom you can not see who is able to put bullets the size of your thumb into a target the size of an orange?
Also, all it would take is a little fertillizer and diesel fuel and POOF your million dollar tank is on it's back like a beetle, helpless, waiting to get stomped on.
Of all the nations on earth te US would be the hardest nut to crack for an invading army, Switzerland would probably be the only other country in the same league.
Without help from HIGH UP in the US military, such a plan couldn't work. China wouldn't even try. Then again, our current administration helped them get ballistic missile technology, who knows what else is possible.
LK