What uses an underwater antennae array???

The news reports about that Russian submarine that they are trying to rescue say that it is entangled in an underwater antennae array. What would use an antennae that is in 600 feet of water. I could understand an underwater cable array for a system like SOSUS, but they are specifically saying antennae. The area that the sub is in is supposed to have been one of the most secure in the old Soviet Union. The news reports also say that the C-5 and C-17 are the first American aircraft to land there since WWII. Isn't the Kamchatka Peninsula where they supposedly shot down KAL Flight 007?

Here is a link to msnbc that says 'antenna'. At first the news outlets were saying cables and fishing nets. What gives? Good catch JIMC

www.msnbc.msn.com...

let's go back to basic physics.... : electromagnetic waves are stopped by a few millimeters of water, the width of this "barrier" depends on the frequency of the electromagnetic wave. Thus, all of your antenna story is crap

Originally posted by ludo182
let's go back to basic physics.... : electromagnetic waves are stopped by a few millimeters of water, the width of this "barrier" depends on the frequency of the electromagnetic wave. Thus, all of your antenna story is crap

I know physics. I have a degree in Applied Physics. Its not my story. That is why I am asking this question. Check the link that SOCIAL_TAKEOVER posted. If it isn't an atennae what is it?

Associated Press is saying that it is part of Russia's coastal defenses. It must be something like SOSUS

news.yahoo.com.../ap/20050806/ap_on_re_eu/russia_navy_accident

"The news reports about that Russian submarine that they
are trying to rescue say that it is entangled in an underwater
antennae array. What would use an antennae that is in
600 feet of water. "

Greetings, a number of maritime surveillance systems use
a tethered antenna/transmitter on the surface to the
sea floor equipment. This provides a reliable means of
transmission for collected data. Such surface tethered
communication systems present a low physical profile
when viewed from a surface vessel minimizing but not
preventing physical detection.

"I could understand an underwater cable array for a system
like SOSUS, but they are specifically saying antennae."

I'm surprized that they have publicly mentioned the fouling
of this surveillance equipment at all. This tether (a combined
hoist cable and sea floor sensors communcation wires to
the surface antennae/transmitter) does have sufficient
strength to foul or damage a subs propulsion system.

"The area that the sub is in is supposed to have been
one of the most secure in the old Soviet Union. "

It still is protected and closely watched. For example,
current airlines that fly from Anchorage International
airport directly to Khabarovsk do not deviate from the
specific corridor designated for that inbound flight.
In other words, if they decided to loiter over the
Cherskiy mountain range or naval military assets
along Sea of Okhotsk coastline. Such a action in itself
would be perceived as a hostile act.

"Isn't the Kamchatka Peninsula where they supposedly
shot down KAL Flight 007?"
Yes, the KAL flt 007 overflew the Kamchatka peninsula
in a southeast direction before they actually fired upon
it. A excellent book on this incident is, The Target is
Destroyed by Seymore Hersh.
On August 18th a joint Chinese and Russian military
exercise will begin.
www.washingtontimes.com...
This potentially tragic sub incident could very easily be
preparations, routine servicing or deployment of this
marine survelliance equipment.

Attu Bosch
Alaska

Electromagnetic waves at certain frequencies do not attenuate at a few milimeters. For example, light waves can propagate up to a 1km or so.

Very low frequency (VLF) waves were (according to Tom Clancy) used in submarine communication. Since they are such low frequency they can propagate around the globe (very long wavelength).

I can't verify that this is a real technology, but the evidence of an antenna array below the water supports that idea.

It also could possibly be doing sonar instead of radar (sound does travel quite well). But if it's specifically an electromagnetic array I would guess VLF.

Originally posted by JIMC5499

Originally posted by ludo182
let's go back to basic physics.... : electromagnetic waves are stopped by a few millimeters of water, the width of this "barrier" depends on the frequency of the electromagnetic wave. Thus, all of your antenna story is crap

I know physics. I have a degree in Applied Physics. Its not my story. That is why I am asking this question. Check the link that SOCIAL_TAKEOVER posted. If it isn't an atennae what is it?

You obviously do NOT know physics very well. At least you don't know classical electrodynamics as it interacts with materials, or you would understand the frequency dependent electric permittivity of dielectrics better.

i made a mistake , you're right light is an electromagnetic wave but when i spoke of electromagnetic wave i meant radio waves.

Originally posted by grad_student

You obviously do NOT know physics very well. At least you don't know classical electrodynamics as it interacts with materials, or you would understand the frequency dependent electric permittivity of dielectrics better.

I'll say it for the last time. I AM NOT SAYING THAT IT IS AN UNDERWATER ANTENNAE ARRAY. I AM JUST REPEATING THAT THE RUSSIANS ARE CALLING IT ONE. I KNOW THAT IT ISN'T FOR ELECTROMAGNETIC WAVES. That being said, "What is it then?"

There can be only two answers to this really:

A) Its a listening post of some sort to detect United States (or anyone else for that matter) clandestine underwater activities near russias remote eastern shores.

B) Its a listening post of some sort to detect underwater ufo's.

altho essentially both could be construed as the same.

(I suppose it could be some sort of communications array - ie projective as opposed to receptive - , but if that were the case, we'd know all about it long ago)

As to the question of 'what type' of listening post? what type of reception is it using? do you really think they would let that info leak out just because a few lives are on the line? we will never know the REAL reason and nature of what it is thats down there and what/how its looking for.

Thank you Master Wu. So this is the russian version of SOSUS. What I find interesting is that the russians are back to calling it a fishing net again.
In case there is anybody who doesn't know what SOSUS is check out the attached link.
www.fas.org...

I can remember when even using the term SOSUS was a security violation.

Hi!,

Firstly I'd like to deal with Ludo, having read various posts by you, to be quite frank I find you entirely insulting!
I find your manner insulting - ie. your first post on this topic saying that someone's information is crap (your word not mine) when it was an extract from a press article!
I find your lack of knowledge insulting - Your comment about electromagnetic radiation only propogating millimetres in water! LOL, plus your comments on another topic about Raptor V Mirage would be down to pilot skill! LOL.
I find your arrogance insulting, I do not think you bring anything positive to this forum and therefore you should refrain from posting and remain as a lurker!
I find you very typically French, which is a shame as I am sure that most of your countrymen would love to change the image of French people being arrogant, morally selfish, smelly and cowardly! You would not make a good ambassador!
Sorry about that folks, I needed to get that off my back! Anyone..on topic!

Having a VLF antenna UNDER the water would make total sense! Subs do use VLF as a communication tool, it is well documented and has been that way for many years. Existing systems that I know of use land based trasmitters, even one of HAARPs research projects is submarine comms. (and yes it does say this on the official website!) The problem with land based transmission is that as the wave travels through the interface between air and water there is a signal strength loss (refraction loss). Placing the transmitter underwater would eliminate this significant loss! Probrably around 65dB for VLF!
The antenna would have to be very large due to the wavelengths involved, (we are talking wavelengths of kilometres here!) basically the lower the frequency the less the attenuation. I'm making an assumption here but I would assume it would be large enough to trap a sub. The structure would have to be strong enough to withstand large currents, the weight of the cable and the corrosive nature of salt water. On the subject of salt water, the closer you get to polar ice caps and thus further away from the equator the lower the concentration of salt (due to ice melt being fresh water). The lower the salt concentration the less the attenuation (due to conductivity) therefore the ideal place to locate the transmitter would be around that region.

I think that it makes sense this could be a VLF antenna, if anyone has a valid reason to argue with this please feel free to do so!

Thanks for reading!

Rob

Originally posted by robbie414
Having a VLF antenna UNDER the water would make total sense! Subs do use VLF as a communication tool, it is well documented and has been that way for many years. Existing systems that I know of use land based trasmitters, even one of HAARPs research projects is submarine comms. (and yes it does say this on the official website!) The problem with land based transmission is that as the wave travels through the interface between air and water there is a signal strength loss (refraction loss). Placing the transmitter underwater would eliminate this significant loss! Probrably around 65dB for VLF!
The antenna would have to be very large due to the wavelengths involved, (we are talking wavelengths of kilometres here!) basically the lower the frequency the less the attenuation. I'm making an assumption here but I would assume it would be large enough to trap a sub. The structure would have to be strong enough to withstand large currents, the weight of the cable and the corrosive nature of salt water. On the subject of salt water, the closer you get to polar ice caps and thus further away from the equator the lower the concentration of salt (due to ice melt being fresh water). The lower the salt concentration the less the attenuation (due to conductivity) therefore the ideal place to locate the transmitter would be around that region.

I think that it makes sense this could be a VLF antenna, if anyone has a valid reason to argue with this please feel free to do so!

Thanks for reading!

Rob

Rob I think that you might mean an ELF (Extremely Low Frequency) system. The US Navy uses such a system to contact its missile submarines to have them come to a shallower depth where their floating wire antennae are effective. The transmitter for this frequency requires a very large antennae array. I didn't mention it because this one was located underwater. I don't know how large the land based array is but I do know that the TACMO plane's antennae is alomst a mile long.

www.fas.org...

Originally posted by robbie414
Hi!,

Firstly I'd like to deal with Ludo, having read various posts by you, to be quite frank I find you entirely insulting!
I find your manner insulting - ie. your first post on this topic saying that someone's information is crap (your word not mine) when it was an extract from a press article!
I find your lack of knowledge insulting - Your comment about electromagnetic radiation only propogating millimetres in water! LOL, plus your comments on another topic about Raptor V Mirage would be down to pilot skill! LOL.
I find your arrogance insulting, I do not think you bring anything positive to this forum and therefore you should refrain from posting and remain as a lurker!
I find you very typically French, which is a shame as I am sure that most of your countrymen would love to change the image of French people being arrogant, morally selfish, smelly and cowardly! You would not make a good ambassador!
Sorry about that folks, I needed to get that off my back! Anyone..on topic!

Having a VLF antenna UNDER the water would make total sense! Subs do use VLF as a communication tool, it is well documented and has been that way for many years. Existing systems that I know of use land based trasmitters, even one of HAARPs research projects is submarine comms. (and yes it does say this on the official website!) The problem with land based transmission is that as the wave travels through the interface between air and water there is a signal strength loss (refraction loss). Placing the transmitter underwater would eliminate this significant loss! Probrably around 65dB for VLF!
The antenna would have to be very large due to the wavelengths involved, (we are talking wavelengths of kilometres here!) basically the lower the frequency the less the attenuation. I'm making an assumption here but I would assume it would be large enough to trap a sub. The structure would have to be strong enough to withstand large currents, the weight of the cable and the corrosive nature of salt water. On the subject of salt water, the closer you get to polar ice caps and thus further away from the equator the lower the concentration of salt (due to ice melt being fresh water). The lower the salt concentration the less the attenuation (due to conductivity) therefore the ideal place to locate the transmitter would be around that region.

I think that it makes sense this could be a VLF antenna, if anyone has a valid reason to argue with this please feel free to do so!

Thanks for reading!

Rob

i'm a moderate but you know when i read some threads on this forum i'm annoyed . In my country i tend to defend the US as a majority of people are anti-american but on this forum i want to defend my country. I don"t want to be insulting but who's arrogant? Come on, the US is the most arrogant nation in the world, it doesn't care of international laws. I've got the bad feeling that the US is near to its decline. Even if i love the US, it seems that it's like a tree that grows very fast, becomes big with a lot of fruits but has no roots... 1776! waow you're a young country and sorry guys but the American culture based on materialism is nothing compared to a lot of other cultures. You show contempt fot the French people because they didn't want to follow you in your illegal war but the best friends do not always agree but are always here when the other needs help. You didn't need help in 2003, you decided to attack a weak country without caring of the aftermath that's all.

I'm just saying that maybe if you would spend the billions dollars you spend in useless projects, in providing help to people in Africa, then maybe people all around the world would love the US and not hate it

With ELF you can only transmit a few bits or bytes per second at most. It is more likely that it is a higher frequency communication antenna to transmit data (from microphones on the seafloor foor example) at faster bitrates. In order to avoid the damping underwater, the antenna should preferentially be as close to the surface as possible, but also to avoid detection by surface vessels preferably just below it. This calls for an antenna attached to something lighter than water for buoyancy, and tethered to the seafloor to avoid it from reaching the water surface.

Originally posted by ludo182
let's go back to basic physics.... : electromagnetic waves are stopped by a few millimeters of water, the width of this "barrier" depends on the frequency of the electromagnetic wave. Thus, all of your antenna story is crap

So could you survive an initial nuclear blast if you were underwater??

Originally posted by warpboost
So could you survive an initial nuclear blast if you were underwater??

That's pretty vague, depends on depth and stuff. Water can be used to shield from radiation and neutrons and is used that way in nuclear facilities.

Originally posted by ludo182
let's go back to basic physics.... : electromagnetic waves are stopped by a few millimeters of water, the width of this "barrier" depends on the frequency of the electromagnetic wave. Thus, all of your antenna story is crap

That's crap. Light penetrates up to several centimeter or meter depending on clarity, for radio waves the same applies but no longer dependent on clarity but on frequency. As with all matter, there is a certain frequency dependency.

Hi JIMC,

Yeah I do agree with you, my use of the terms VLF really covers ELF too www.fas.org...

Sorry about that little outburst btw, apologies to other forumites! FYI Ludo I am a British aerospace engineer.

Simon, HF transmission may allow higher data transfer speeds but it has no water penetrating properties. VLF/ELF is used as a bell ringer, the sub can receive small messages and come to a lesser depth to gather further information. My point was that placing the transmitter underwater would reduce refraction losses. The simplest explanation is that this net was either a fishing net or a sosus style receiver, the interesting part of this for me at least is that maybe the russians have taken a different approach to ELF/VLF transmission by placing the antenna under water. I agree that the effective length of this would be extremely long, perhaps long enough to entangle a sub!

Just a thought though.

It's probrably just a fishing net!

Cheers

Rob

The penetration of 5 MHz waves in water is indeed around 0.12m, for 5 Hz this changes to 112 meter. If the antenna is placed just 1.2 m below the surface of the sea, you could communicate with frequencies below the order of 50 kHz. That allows still MUCH faster communication than by VLF/ ELF. That seems a more likely explanation to me, to communicate data at reasonable speeds while trying to keep the antenna hidden from detection by placing it just below the surface through tethering it to the seafloor.

www.iihr.uiowa.edu...

[edit on 9-8-2005 by Simon666]