On Friday, January 17, 2014 10:45:08 AM UTC-5, Eric Jacobsen wrote:> > I think when it was originally done it wasn't that well known for long > enough to be useful. Like most things of this type, I always figured > they shut it down because they had come up with a better substitute > and didn't need it any more. >The US Navy (publicly) says that that substitute is VLF, which itself has lots of disadvantages. IIRC VLF can go tens of km, so you need multiple VLF stations to be able to cover the entire globe. Plus VLF is fairly easy to detect, this itself is a disadvantage for what is supposed to be a secretive secure system. So the choice between VLF and ELF is definitely not obvious. And if it's not obvious, when there is clear need for the functionality and resources are available, why not pursue both. Again, hindsight is 20/20, further what with long development and deployment time, it was a very hard decision to make (or more precisely, a very hard sequence of decisions).
Error correcting codes for extremely high error rates
Started by ●January 14, 2014
Reply by ●January 17, 20142014-01-17
Reply by ●January 17, 20142014-01-17
On Friday, January 17, 2014 11:14:26 AM UTC-5, julius wrote:> On Friday, January 17, 2014 10:45:08 AM UTC-5, Eric Jacobsen wrote: > > > > > > I think when it was originally done it wasn't that well known for long > > > enough to be useful. Like most things of this type, I always figured > > > they shut it down because they had come up with a better substitute > > > and didn't need it any more. > > > > > > > The US Navy (publicly) says that that substitute is VLF, which itself has lots of disadvantages. IIRC VLF can go tens of km, so you need multiple VLF stations to be able to cover the entire globe. Plus VLF is fairly easy to detect, this itself is a disadvantage for what is supposed to be a secretive secure system. > > > > So the choice between VLF and ELF is definitely not obvious. And if it's not obvious, when there is clear need for the functionality and resources are available, why not pursue both. > > > > Again, hindsight is 20/20, further what with long development and deployment time, it was a very hard decision to make (or more precisely, a very hard sequence of decisions).The station in Cutler, ME (http://goo.gl/maps/QQPH5) is easy to pick up several states away, but underwater is a different story.
Reply by ●January 17, 20142014-01-17
On Friday, January 17, 2014 2:23:54 PM UTC-5, John wrote:> > The station in Cutler, ME (http://goo.gl/maps/QQPH5) is easy to pick up several states away, but underwater is a different story.Cool, thanks for the info! Since I'm in Boston area, I should check this out sometime. I did find a few links to "desktop VLF receiver antenna".
