Keeping the blogosphere posted on the goings on of the world of submarines since late 2004... and mocking and belittling general foolishness wherever it may be found. Idaho's first and foremost submarine blog. (If you don't like something on this blog, please E-mail me; don't call me at home.)

Friday, January 18, 2008

New Technologies To Aid Submarine Stealth?

During the last week, there have been announcements of a couple of new technologies that could make submaries even harder to detect. The first one, which has actually been built, is a system to send encrypted communications to submarines from expendable bouys that can transmit a digital signal underwater as far as 175 nm. Excerpt:
To communicate with a submerged submarine safely, a gateway mechanism is required to deliver messages deeper than periscope depth. The Deep Siren Tactical Paging system is comprised of a disposable gateway buoy with an antenna that gathers radio-frequency signals and converts them to Deep Siren acoustic signals that penetrate the water and are received by the submarine's sonar system. These acoustic signals are then converted on board the submarine to text messages with the Deep Siren receiver. The Deep Siren system also includes a portable transmit station which can be located on shore or carried on board a ship or airplane. "You want to have this be a global capability, where the buoy can be called from anywhere in the world," Matzelevich says.
Working with RRK Technologies, Ltd., in Glasgow, Scotland, and Ultra Electronics Maritime Systems in Dartmouth, Nova Scotia, Raytheon is developing a Deep Siren system that includes expendable buoys that are five inches (12.7 centimeters) in diameter and about 3.5 feet (one meter) long with antennas that receive signals from a constellation of Iridium Satellite, LLC, communication satellites. The buoys—designed to stay afloat for up to three days—can be ejected out of the sub's trash disposal unit without major modifications to the vessel. In this way, subs can set up their own acoustic networks without the need to tow an antenna.
The story says the system is supposed to get an at-sea eval in June as part of the Communications At Speed And Depth initiative. The story made it seem that subs only communicate now by using the Floating Wire Antenna at periscope depth, but I'm assuming that the writer didn't understand what the retired submarine Captain was saying.

The other new breakthrough has to do with defeating active sonar by "bending" sound waves around a submarine. This one is a fascinating theoretical advance, but I really don't see it having any practical application. (The abstract is located here.) The problem is that is appears that this would require covering the submarine with honeycombs of a still-undiscovered "metamaterial" which, I'm guessing, wouldn't have much in the way of the strength needed to retain it's shape at depth while still allowing for hull compression. If they can eventually tech this one out, I wouldn't expect to see boats using it for at least several decades.

8 Comments:

Anonymous Anonymous said...

"The buoys—designed to stay afloat for up to three days—can be ejected out of the sub's trash disposal unit without major modifications to the vessel. In this way, subs can set up their own acoustic networks without the need to tow an antenna." Seems like the presence of the buoy would be indicative of the presence of a submarine which would remove some of the stealth.

1/18/2008 12:14 PM

 
Blogger Vigilis said...

Think about that. Which is better, making an enemy believe there may be submarines in a dozen, widely dispersed coastal areas, or actually having submarines there? - Great decoys.

1/18/2008 3:15 PM

 
Anonymous Anonymous said...

To anonymous: Seems like the presence of the buoy would be indicative of the presence of a submarine which would remove some of the stealth.

Go ahead and re read the original post: system to send encrypted communications to submarines from expendable bouys that can transmit a digital signal underwater as far as 175 nm.

Now if the buy can be dropped and stay afloat for three days, who says the sub can't be 150 miles away by the next morning? Not exactly still "in the neighborhood" is it?

Chief Torpedoman

1/18/2008 8:38 PM

 
Blogger midwatchcowboy said...

Matzelevich is not a sub guy. He's in business development (salesman).

As for the distance of use: YMMV.

The floating wire may have been referring to this:
"Undersea FORCEnet Satellite Communications (SATCOM) FY 2008 funding provides the Internet Protocol (IP) connectivity between Anti-Submarine Warfare (ASW) platforms to conduct collaborative ASW. Connecting the platforms for
collaborative ASW enables sharing of time critical queuing, classification, and targeting data, provides a means for precluding blue-on-blue engagement, and
ensures rapid positioning of ASW platforms into the best attack posture to prosecute the threat submarine.
The FY 2008 budget also reflects the procurement of the Airborne Automated Digital Network System (aADNS) to provide High Frequency Internet Protocol (HFIP) capability as the primary transfer path for Internet Protocol (IP) data and Automatic Identification System (AIS) data on and off the E-2C platform."

1/19/2008 6:00 AM

 
Anonymous Anonymous said...

So there will finally be a legitimate mail buoy watch?

1/19/2008 7:14 AM

 
Anonymous Gryphon said...

I would presume the "pager buoy" would be left behind in baffles, and the range of 100+NM is a bit optimistic (unless of course there was a "transmit/listen period" programmed in to make certain Sonar was looking in the right direction/time?

(Just a BT SS1 asking you ST's how it'd work)

1/21/2008 4:03 PM

 
Anonymous Anonymous said...

OBTW,
HFIP ain't there yet, and probably won't get there. Too many danged variables to the RF path... 75baud at best?!?

1/21/2008 4:06 PM

 
Blogger loddfafnir said...

midwatchcowboy,
Matzelevich was a sub guy, my first CO as a matter of fact.

1/23/2008 6:57 PM

 

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