http://www.theregister.co.uk/2009/06/02 ... ren_trial/
Royal Navy trials 'paging system' for submarines
By Lewis Page Posted in Science, 2nd June 2009 10:19 GMT
US arms behemoth Raytheon says that the Royal Navy has tried out its new Deep Siren satcomms "paging system" for submarines, and was very impressed.
The company quotes an unnamed UK Ministry of Defence (MoD) spokesperson as saying that Deep Siren is "the first step toward a transformational capability that will change the way we operate submarines in the future".
One of the great problems of submarines, particularly since nuclear power let them stay submerged for much longer periods, has been communicating with them. If a sub comes to a relatively shallow depth and streams a suitable antenna it can receive special low-frequency, low-bandwidth transmissions sent from dedicated shore stations. Otherwise the only option is for the sub to come to periscope depth and put up an antenna.
All this has meant that modern subs are normally only contactable at prearranged times, during which periods the sub is often more vulnerable to detection than it would otherwise be; and probably constrained in speed too. If a sub is running deep and/or fast, it probably can't be reached at all.
That was OK back in the Cold War, when missions didn't usually require a submarine captain to receive new instructions or information very often and a sub needed to stay well hidden from powerful enemy naval forces. But nowadays the lone-wolf submariners, if they're to be useful, need to be more reachable - and in a typical modern war the maritime opposition is negligible, so it's possible to relax somewhat on staying hidden.
Hence Deep Siren, a fairly basic piece of kit. The idea is that you drop a small buoy into the sea, somewhere within a hundred nautical miles or so of the sub's position. The buoy has Iridium satcomms and an acoustic transducer. Then you can send a message over Iridium to the buoy, which will pass it on acoustically through the water to the sub "at classified depths and speeds", according to Raytheon.
The latest trials referred to by the company were conducted by ships involved in the TAURUS 09 deployment, currently underway, in which the Royal Navy's amphibious task group is conducting exercises around the Indian Ocean.
It would, as the nameless Brit spokesperson says, be a big change in the submarine world if the undersea warships genuinely became reachable in the way that surface vessels and aircraft are. But, as the spokesbeing also says, this is merely a first step. Deep Siren is merely a one-way paging system: and acoustic through-water comms can be highly unreliable.
Furthermore, Raytheon don't really seem to be pushing it along very fast. The company says that it isn't even certified for use aboard aircraft yet. Dropping the Deep Siren buoys from patrol planes or naval helicopters would probably be the normal means of deploying them, so as it stands the system plainly isn't ready for prime time