March 13, 2016

Japanese SeaWeb and Stealth Jet Detection Research - Quite Public

Modern SeaWeb (mostly underwater communications, detection and database) systems are no longer restricted to Cold War era seafloor wired together SOSUS sensors. As the diagrams below show - there is likely to be much greater use of multiple sensor (eg. LIDAR, infrared, magnetic anomally and sound) nodes that work to may platforms (submarines, UUVs, UAVs, USVs, surface ships, shore stations, patrol aircraft and satellites). 

Nodes may be fixed seafloor, tethered, surface floating, many platform mobile, popping-up to send data bursts to satellite (eg. wavegliders) etc. 

Underwater communications/relays between the nodes may be much more dependent on VLF-ELF radio waves or sound waves rather than cumbersome SOSUS cables.

All major naval powers have their research and installation programs. This continues with varying degrees of secrecy depending on national security culture. China and Russia maintain tight security while Japan or the US security may not be so tight (for reasons including commercial opportunities, organisational pride, and justifying taxpayer funding).

Discovered today is some interesting diagrams (below) from Japan's Ministry of Defense (MOD). Two from the Acquisitions, Technology and Logistics Agency (ATLA)

Above is a Japanese SeaWeb concept diagram and description at as at March 13, 2016.

(Translation from Japanese by right-click mouse "Translate to English" and then by Pete)

Title Research of advanced underwater acoustic communication network technology (warships equipped Research Institute)

 In comparison with strong radio wave linear propagation, a sound wave in the sea is refracted in accordance with the change in the water temperature and water pressure. Sound wave propagation follows a complex path. Thus in order to stretch a digital communication using sound waves in the sea, it is necessary to suppress the influence of multiple reflections bouncing off the sea surface and the seafloor.

 Therefore, in this Japanese Defense Institute - to suppress the influence of multiple reflections, we conducted a study on advanced underwater acoustic digital communications that enables telecommunication.

(Courtesy Japanese language document from Japan's MOD ATLA agency 2015 in connection with )

Above is a Japanese  concept diagram from as at March 14, 2016.

(Translation from Japanese by right-click mouse "Translate to English" and then phrase order rearrangements by Pete) 

Research of next-generation radar warning and control (electronic equipment Institute). We aim to further improve the performance of warning and control radar needed to respond in the future of stealth aircraft and ballistic missiles. 

Unlike previous performance improvements, which were acheived by the size of the antenna, a  distributed network of small antennas can be electronically configured to take account of the size of the attacking aircraft or missile. We are studying a distributed radar network to achieve what can be considered a large-scale radar equal to or higher than current detection performance.

Thus we shall apply the most advanced MIMO (Multi-Input Multi-Output) Radar techniques to achieve an equivalently large antenna optimally combining signals from a network of small antennas.


SeaWeb - If readers type in seaweb on the upper left seach box of Submarine Matters they will see several detailed articles (words, diagrams, map) in English on SeaWeb. These are mainly from the US also from Singapore and Japan.

Radar Against Stealth - Presumably China and Russia (Iran?) are working on similar radar concepts as an air/missile defence priority. China and Russia have to face current Western stealth jets (F-35, F-22s and B-2s) while the West may still have 10 years until Russian and Chinese stealth jets become fully operational.



MHalblaub said...

Dear Pete

Nice pictures but the idea is not so new:

I made my first little video translations:
0:33 "President of Germany Horst Köhler ‘plunges’ with German Navy U 33."

Slow but nice;-).

I try to find some more looks from the inside with more information.

It is still sunday here.


Anonymous said...

Hi Pete,

I like to draw your attention to a lesser part of maritime surveillance: diver-detection, base-protection and civilian maritime infrastructure-protection. Those systems come from the same producers of sonars, seaweb etc.

I came across this YT video - dated from Dec 2014 - from DSIT Underwater Systems' official YT-account. It's in Vietnamese.

FYI the US lifted its' arms-sanctions against VN in Oct 2014 and specifically for maritime systems. DSIT is owned by US-based Acorn Energy.

The French, Isreali Navies deploy the same systems.

There have been rumors for a while now that VN has bought not only base-protection systems BUT a complete sonar-net to counter China in the SCS. Rumors have it that Atlas Elektronik supplies the UUV-part of net.

It would interesting if the Western countries gave VN a big discount in exchange for threat-libaries/sub-signature libaries.

Peter Coates said...

Hi MHalblaub

Yes some information about SeaWeb is available re

If readers type in seaweb on the upper left seach box of Submarine Matters they will see several detailed articles (words, diagrams, map) in English on SeaWeb. These are mainly from the US also from Singapore and map from Japan.

I don't see the point of OR not much happens except long shots of a 212A riding the tide at periscope height.