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shen

Senior Member
but the peaks and valley on the Chinese side of the continental shelf are in the higher position :)

technological advances are important, but you can't overcome inherent physical limitation of LF passive sonar in littoral water.
 

Jeff Head

General
Registered Member
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"
Akula could not be reliably detected by SOSUS, and without SOSUS the GIUK
threatened to become an avenue rather than a chokepoint, which is where FDS enters the
story."

FDS is the upward looking sensor network that can detect passing submarines, but not tracking them at long range.
It's a 2011 working paper, and indeed the original system developed in the early Cold War years was impacted by the Akula.

But it would be a grave mistake to presume that the US has not improved the system,...and that's all I will say on it.
 

shen

Senior Member
It's a 2011 working paper, and indeed the original system developed in the early Cold War years was impacted by the Akula.

But it would be a grave mistake to presume that the US has not improved the system,...and that's all I will say on it.

That 2011 paper supports my position that SOSUS is ineffective against Soviet SSN after the introduction of Akula. If you have a source that support your position, please share.
 

shen

Senior Member
Sosus was employed in the Wespac AOR, Project Azorian the CIA's attempt at recovering a sunk K129 submarine was based on data from Sosus and that submarine sits north of Midway.
considering that Sosus was developed in the 1950's becoming operational in the 1960's. It's likely that any modern system would be worlds away form the cold war era system. And the old school Sosus was a impressive system even capable of tracking whales.

yeah, but whales helpfully make sound in the frequency that can travel long distance in water and tracked by SOSUS. modern SSN or SSK on batteries or AIP don't.
 

SamuraiBlue

Captain
but the peaks and valley on the Chinese side of the continental shelf are in the higher position :)

technological advances are important, but you can't overcome inherent physical limitation of LF passive sonar in littoral water.

Sound wave propagation differs from EM waves and/or light propagation in which it will go around any physical barriers especially LF. LF also bounces off thermal layers like radio waves bounces off the magnetosphere of earth enabling you to listen to radio frequencies on the other side of the planet. Signature sound patterns can be isolated through pattern recognition software and noise cancellation software. The only limit is you can't really define distance even if you have more then one listening point since the sound waves may have bounced off multiple times.

As for subs SSN whether modern or not makes heck of a noise when traversing at 20knts and above through it's reactor cooling pumps and steam generators. You also can't be too confident with SSKs if they are not properly insulated noise can seep out especially in the 60hz harmonics since a sub's hull is like one big resonator.
 
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FORBIN

Lieutenant General
Registered Member
It's official now.
Japan, U.S. run undersea detection system for Chinese submarines

TOKYO — Japan’s Maritime Self-Defense Force and the U.S. Navy are jointly operating an undersea submarine detection system on the floor of the Pacific side of the Nansei Islands chain including Okinawa as part of efforts to counter China’s rising maritime activities, Kyodo News learned Wednesday.


The latest model of the sound surveillance system, or SOSUS, allows Tokyo and Washington to detect Chinese submarines traveling from the East China Sea and Yellow Sea to the Pacific, according to sources in the Defense Ministry and the MSDF.

It is the first time that the existence of a listening system solely targeting China has been revealed.

As the system is “top secret in the Japan-U.S. security system,” the MSDF explains outlines of the U.S.-developed system only to a group of key figures in the Japanese government including the prime minister and the defense minister..... to read more
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I guess everyone speculated it's existence including myself.
Japan to Okinawa possible ?
 
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