24 August 2019, 00:01:00 *

Login with username, password and session length
Welcome to War and Tactics!    War and Tactics Forum is currently undergoing some modifications that might disable features you are used to. This is unabvoidable as we have to update the forum engine to a new structure that is incompatible with many of the features we had used so far. The good news: WaT will be more secure and stable, and most of the features we uninstalled will be a natural part of the new structure anyway. For the rest we will be looking for solutions. (APR 23, 2018)
   
  Home   Forum   Help ! Forum Rules ! Search Calendar Donations Login Register Chat  
Pages: [1]   Go Down
  Print  
Share this topic on Del.icio.usShare this topic on DiggShare this topic on FacebookShare this topic on GoogleShare this topic on MySpaceShare this topic on RedditShare this topic on StumbleUponShare this topic on TechnoratiShare this topic on TwitterShare this topic on Yahoo
Author Topic: Submarine Comms - A Giant Step  (Read 2745 times)
Rattler
WaT Supporter

*

Offline Offline

Germany

Location: Med Island
Posts: 2268




View Profile WWW
« on: 18 July 2010, 10:56:18 »
ReplyReply

As you all probably know comms with a submerged submarine are tricky: In order to establish two-way comms the sub has to almost surface and stick an antenna out of the water (not really stealthy), if it is submerged the communications are only one way via extreme low frequency waves (3-300 Hz) that require antennaes of hundreds of miles length: The lower the frequency, the longer the wave:  For 3 Hz frequency the wave length would be 100.000 km, i.e. you would have to build antennaes of around 12.000 km length to communicate, and you need earths mass to create the power (this is why it is one way only):


where c= speed of light in m/s, lambda=wave length in m, and f the frequency in Hz.

This is, of cause, not really practical, and solutions to this problem have been searched for since long, now it finally seems light is to be seen at the horizon, Lockheed Martin has developed a new system in the Comms at Speed and Depth (CSD) program, Within a few years, all U.S. Navy subs will be equipped with expendable high-tech communications buoys that will allow two-way real-time chat, data transfer and e-mail.

The system rotates around some expandable thethered buoys that are ejected from the subs and communicate with them through optic fibres, establishing comms with ground, space- naval- or airborne units. Three buoys are in development, two of them tethered to the sub and one freewheeling acoustic-to-RF buoy which can be dropped out of an aircraft or even launched out of a sub’s trash shoot.

Here some schemes how it is supposed to work:







Rattler
Logged

"War does not determine who is right, war determines who is left...": The Rattler Way Of Life (thanks! to Solideo)... http://www.youtube.com/watch?v=n9v3Vyr5o2Q
Pages: [1]   Go Up
  Print  
 
Jump to:  

Unique Hits: 26038908 | Sitemap
Powered by MySQL Powered by PHP Powered by SMF 1.1.16 | SMF © 2011, Simple Machines
TinyPortal v0.9.8 © Bloc
Valid XHTML 1.0! Valid CSS!


Google visited last this page 21 June 2019, 15:45:19