mmm@uunet.UU.NET (04/10/90)
From: <ames!ames!claris!portal!cup.portal.com!mmm@uunet.UU.NET> Why would it be hard to communicate with a submerged submarine? You could run a buoy to the surface on a fiber optic cable, and a transceiver could communicate with a satellite. When you're done, the buoy could be reeled in as it's air was let out. Obviously, such things are secret activities, so the Navy wouldn't advertise them. Especially if the sub communication myth needed to be preserved to support building a big ELF transmitter. But it's hard to believe that SOME kind of technology for communicating with submerged submarines doesn't exist.
henry@zoo.toronto.edu (Henry Spencer) (04/11/90)
From: henry@zoo.toronto.edu (Henry Spencer) >From: <ames!ames!claris!portal!cup.portal.com!mmm@uunet.UU.NET> >Why would it be hard to communicate with a submerged submarine? You could >run a buoy to the surface on a fiber optic cable, and a transceiver could >communicate with a satellite... Many such things can be done if the sub is willing to come fairly near the surface; the point is that sub drivers, for good reasons, do not like doing that routinely. They especially do not like exposing *anything* on the surface itself, because radars designed for detecting sub periscopes can spot antenna buoys very quickly. In any case, schemes like this are useless for the PAL application: maintaining communication with an *uncooperative* submarine. >... it's hard to believe that SOME >kind of technology for communicating with submerged submarines doesn't exist. Communicating through hundreds of meters of water from thousands of miles away is just plain *hard*. The USN would love to have better methods of doing it. Henry Spencer at U of Toronto Zoology uunet!attcan!utzoo!henry henry@zoo.toronto.edu
terryr@ogicse.ogi.edu (Terry Rooker) (04/11/90)
From: terryr@ogicse.ogi.edu (Terry Rooker) In article <15387@cbnews.ATT.COM> ames!ames!claris!portal!cup.portal.com!mmm@uunet.UU.NET writes: > >Why would it be hard to communicate with a submerged submarine? You could >run a buoy to the surface on a fiber optic cable, and a transceiver could >communicate with a satellite. When you're done, the buoy could be reeled in >as it's air was let out. > >Obviously, such things are secret activities, so the Navy wouldn't advertise >them. Especially if the sub communication myth needed to be preserved to >support building a big ELF transmitter. But it's hard to believe that SOME >kind of technology for communicating with submerged submarines doesn't exist. The Navy has SOME kind of technology for communicating with submerged submarines. Those methods are are various combinations of slow or revealing. For example, your suggestion would require to sub to have a buoy pierce the surface for approximately a minute, even with high speed burst communications. While the buoy was surfaced it is terribly easy to spot the sub. Remember we are talking about communications in a possibly high threat situation. Such a method would require the sub to surface just when you want it submerged the most. For what it is worth the USN subs use a variation of the method for routine transmissions. I don't know what the sub communication myth is. Any elementary science text will tell you radio waves to penetrate water very well. So to communicate with a submerged sub, you need LF and ELF frequencies. The advantages of not peircing the surface increase the sub's chances by an order of magnitude. The sub is still at risk. Near the surface they are still easy to detect. The antenna for LF, ELF coomunications is very long and hinders the sub's mobility. In the zero sum game of defense politics, the Navy (and other services) may overstate its case, but the SSBN's have the least reliable communications of any element of the triad. They are the most survivable also which justifies the communications hassles. -- Terry Rooker terryr@cse.ogi.edu
heflin@cod.nosc.mil (Greg R. Heflin) (04/11/90)
From: heflin@cod.nosc.mil (Greg R. Heflin) >From: <ames!ames!claris!portal!cup.portal.com!mmm@uunet.UU.NET> >Why would it be hard to communicate with a submerged submarine? You could >run a buoy to the surface on a fiber optic cable, and a transceiver could >communicate with a satellite. When you're done, the buoy could be reeled in >as it's air was let out. > But this would make detection of a submarine much easier. I thought the main advantage of a missle submarine was that *IF* it stayed submerged *AND* it did not send out messages that in the open ocean a submarine is very hard to detect. And what happens if the satellite (or any other methode of 'continually enabling the PALs') either fails or it attacked/destroyed? -gregory -- -gregory Just my two cents which shouldn't make a flame, unless you rub them real hard.
tek@CS.UCLA.EDU (Ted Kim (Random Dude)) (04/11/90)
From: tek@CS.UCLA.EDU (Ted Kim (Random Dude)) >From: <ames!ames!claris!portal!cup.portal.com!mmm@uunet.UU.NET> >Why would it be hard to communicate with a submerged submarine? You could >run a buoy to the surface on a fiber optic cable, and a transceiver could >communicate with a satellite. When you're done, the buoy could be reeled in >as it's air was let out. > >Obviously, such things are secret activities, so the Navy wouldn't advertise >them. Especially if the sub communication myth needed to be preserved to >support building a big ELF transmitter. But it's hard to believe that SOME >kind of technology for communicating with submerged submarines doesn't exist. >From what I have read in the open press, it's not really much of a secret. Many subs do have the system you mention. The sub comes up near the surface and reels out this antennae that trails on the surface. But, the whole idea about subs is they want to be stealthy, so they don't want to be struck near the surface or restricted in their maneuvers any more than they have to be. Even if they could talk all the time, they would probably only listen as to not give away their position. BTW, the ELF has such low bandwidth about all they can say is "Get into position to recieve the real message via radio". Another system carried by some subs is to release a bouy which plays a recorded message after a time delay (so the sub does not give away it's position). Finally, the USN is working on some type of blue-green laser system. The hope is subs could talk submerged at reasonable depth with high bandwidth. -ted Ted Kim UCLA Computer Science Department Internet: tek@penzance.cs.ucla.edu 3804C Boelter Hall UUCP: ...!{uunet|ucbvax}!cs.ucla.edu!tek Los Angeles, CA 90024 Phone: (213) 206-8696
sr2b+@andrew.cmu.edu (Samuel Joseph Robb) (04/11/90)
From: Samuel Joseph Robb <sr2b+@andrew.cmu.edu> In response to <ames!ames!claris!portal!cup.portal.com!mmm@uunet.UU.NET>: >Obviously, such things are secret activities, so the Navy wouldn't advertise >them. Especially if the sub communication myth needed to be preserved to >support building a big ELF transmitter. But it's hard to believe that SOME >kind of technology for communicating with submerged submarines doesn't exist. As I understand it, there are two primary reasons for one-way sub communications. The first is the power required for ELF transmission; you need a very large power source, which you can't fit into a sub and expect it to do anything useful. The second is secrecy. Subs depend on stealth and suprise to be effective; if they loose that advantage, then they loose their effectiveness (until they can hide from enemy eyes again.) ANY radio transmission, no matter how tightly shielded, has the potential to be monitored. A submarine broadcasting at any frequency, therefore, has the potential to be monitored, and have it's position plotted by an enemy. By engaging in one-way communication, submarines are able to keep their exact locations secret, and maintain their effectiveness. Surface ships are not bound by the same rules as submarines, since (being on the surface) they are visible by satellite, radar, naked-eye sightings, etc., so a limited amount of EMF transmission, even in wartime, is more beneficial than harmful. -Samrobb -sr2b+@andrew.cmu.edu
carlson@gateway.mitre.org (Bruce Carlson) (04/12/90)
From: carlson@gateway.mitre.org (Bruce Carlson) In article <15387@cbnews.ATT.COM> ames!ames!claris!portal!cup.portal.com!mmm@uunet.UU.NET writes: > > >From: <ames!ames!claris!portal!cup.portal.com!mmm@uunet.UU.NET> >Why would it be hard to communicate with a submerged submarine? You could >run a buoy to the surface on a fiber optic cable, and a transceiver could >communicate with a satellite. When you're done, the buoy could be reeled in >as it's air was let out. > >Obviously, such things are secret activities, so the Navy wouldn't advertise >them. Especially if the sub communication myth needed to be preserved to >support building a big ELF transmitter. But it's hard to believe that SOME >kind of technology for communicating with submerged submarines doesn't exist. >From what I remember reading of current submarine comm, they have at least two capabilities (maybe more). They can tow an ELF antenna and receive communications while under the water. If they want to transmit they use some type of recording medium, a burst transmitter, and a buoy that is floated to the surface. The transmission is initiated by a timer, so when the buoy/radio transmits the sub is already out of the area. I don't think they have any significant amount of "interactive" communications in real time. I don't remember where I read the above info, so take it with a grain of salt. Bruce Carlson
lwch_cif@uhura.cc.rochester.edu (LE VENGEUR) (04/14/90)
From: lwch_cif@uhura.cc.rochester.edu (LE VENGEUR) In a couple of articles ago someone mentioned about the use of laser to communicate with the base on the surface. I believe the laser in question is a gas laser called Copper Vapor Laser. In its blue-green mode (wavelength of .5105 mus) it can travel easily through the salt water of the ocean. Its one of the most powerful gas laser there is requiring only 1 mirror for its stimulated emission and amplification. Approximately 40 watts in power and has a 15 kHz repetition rate. Thats all I learned so far in the Optics Undergrad. Prog. here in Rochester, please if possible follow up with the laser's actual role or its prospect in the submarine's submerged communication. Thanx Lea-Wei