Can Australia Monitor Foreign Submarines Along Our Coasts?

I'm now relating the April 24, 2019's article how Indonesian submarine KRI Nagabanda sailed south along the West Australian coast with the likelihood that Australian undersea sensors picked up Nagabanda's movements. In 1963-64 KRI Nagabanda's commander claimed/hoped that his submarine journeyed "without being noticed by Australian ships" but the undersea sensors may have alerted Australian ships to KRI Nagabanda's presence.

As KRI Nagabanda stayed outside the 50 mile coastal limit and Indonesia-Australia were not at war they allowed. KRI Nagabanda to continue unhindered. 

UNDERSEA SENSORS

When KRI Nagabanda sailed in 1963 two types of sensors had been used by Australia and/or its UK and US allies for 45 years

Undersea sensors to detect submarines have a long and established history including:

-  magnetic anomaly indicator loops developed and first used by the UK Royal Navy in 

   October 1918 to destroy German submarine UB-116, 

Relating this technology to Australia an Australian, Dr Richard Walding comments “Indicator Loops are long lengths of cable laid on the seafloor of harbours to detect enemy submarines.  They were developed by the Royal Navy in the early 1900s and first trialled at the end of WW1.  They were then successfully deployed in WW2 in British ports both at home, in the Dominions (Australia, Canada, New Zealand, South Africa, Kenya, Ceylon, Penang) or in allied harbours (Iceland, Holland, Dardanelles). By 1942 the United States had adapted this technology for its own needs." 

Comment: Magnetic anomaly sensors might still be used to protect Australia's Fleet Bases East and West. This may be related to the University of Adelaide, Australia's Institute for Photonics and Advanced Sensing (IPAS) research. Angela Skujins for Defence Procurement International, 14 April 2019, writes:

"One of the IPAS projects will utilise [quantum] magnetometers in underwater geophysical discovery contexts to track submarine activity.

Professor Andre Luiten said the technology, primarily employed to detect variations caused by the presence of ferrous (unoxidized) iron in the total magnetic field, will be applied for Defence to discover underwater vessels.

“These magnetometers can detect very small magnetic fields,” he said. “The goal of this project is to build sensors that go on the seabed which detect the presence of submarines through their properties. You’d essentially set up a trip wire around assets that are of importance to Australia.”"

-  and passive acoustic sensors "hydrophones", (also see)  developed and used in 1918 against UB-116 by the British. The US adopted this technology and applied it worldwide as the Sound Surveillance System (SOSUS) network. SOSUS was/is most famously used in the North Atlantic (GIUK Gap) 

A US Navy publication on SOSUS also reveals “After a series of successful detection trials with a U.S. submarine, the Navy decided by mid-[1952] to install similar arrays along the entire U.S. East Coast – and then opted two years later to extend the system to the West Coast and Hawaii as well." 

If SOSUS (now the IUSS) has been monitoring submarine activity near US coasts for decades, then might Australia be monitoring subs around our own coasts? 

Map A. (above) positions where KRI Nagabanda set sail from Kupang, West Timor, Indonesia (see white rectangle) in relation to Australia. 

Now look at the Map B. (above) showing "Deployments" of hydrophone nodes. When KRI Nagabanda moved down the Western Australian coast as far south as Perth it may have moved over the 2 red dots/nodes and black hydrophone/SOSUS dot/nodes. 

These hydrophones may have been present in 1963-64 and where only revealed in the 2000s. The dots/nodes belong to Australia's dual (naval-civilian) use Integrated Marine Observing System (IMOS). IMOS has a civilian image but its "Operational Partners" include the Royal Australian Navy and the Australian Department of Defence's "Defence Science and Technology Group (DST Group)". IMOS uses passive acoustic (hydrophone) equipment monitors natural and "man-made noise sources". Perhaps hydrophone arrays were/are strung between the nodes. Naval processing of data from "man-made noise sources" would occur at shore establishments and then passed on to anti-submarine ships, submarines and aircraft of the RAN and USN.

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Map C. (above) Another organisation related to IMOS is the Australian Ocean Data Network (AODN) whose partners also include the "Royal Australian Navy" and the "Defence Science and Technology Group (DST Group)".

Does Map C. at the bottom of the "About Us: IMOS" website imply an undersea sensor ring around Australia's coasts? Draw your own conclusions!

Pete