Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!tut.cis.ohio-state.edu!att!cbnews!military From: sr2b+@andrew.cmu.edu (Samuel Joseph Robb) Newsgroups: sci.military Subject: Re: Sub communications Message-ID: <15459@cbnews.ATT.COM> Date: 11 Apr 90 03:17:10 GMT References: <15387@cbnews.ATT.COM> Sender: military@cbnews.ATT.COM Lines: 33 Approved: military@att.att.com From: Samuel Joseph Robb In response to : >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