Since 2005 Australia has been hosting the Talisman Sabre joint naval exercises every two years. The main participants are Australia and the U.S. but there are also smaller contingents from other Pacific allies. In 2019 that included Canada, Japan, Britain and New Zealand along with observers from twelve other nations. There are also some uninvited observers and in 2019, for the second time in a row, China is unofficially attending in July for the main exercise that lasts for about two weeks. Ships and aircraft begin to assemble in June and the last of the smaller exercises last into August. Not counting the Chinese, about 34,000 military personnel take part at sea and ashore in Australia for the amphibious operations.
The Chinese participant is one of their nine Dongdiao class Type 815 AGI (Auxiliary General Intelligence, or electronic reconnaissance) vessels. In a tradition stretching back to the Cold War (1948-1991), uninvited AGIs show up uninvited at naval exercises held in international waters. There these ships loiter while collecting all the electronic and photographic data they can.
This year’s Chinese visit was tenser than the last one because a month earlier three Chinese naval ships (frigate, amphibious and supply) made port visits in Australia on their way back from a tour with the international anti-piracy patrol off Somalia. These side visits by the Somali task forces have been going on for over a decade, and often extend to Europe and South America. Such visits have been made to Australia before but this time the government did not give it much advance publicity. The hostility to the Chinese had to do with the South China Sea situation and the Chinese AGIs showing up off Australia. China claims to own most of the South China Sea and is making similar claims on other areas in the Western Pacific. An international court ruling confirmed that China is in violation of international law and agreements that China had signed on to. The Chinese ignored this and are increasingly hostile and threatening towards foreign warships, including Australian and American ones, passing through the South China Sea.
While the growing number of Chinese warships visiting foreign waters appear threatening, the AGIs are not warships but in many respects are more of a threat. In the last twenty years, China has become a major user of AGIs which, during the Cold War, were mainly used by the U.S. and Russia. The Americans still have a lot of them but Russian AGIs have largely disappeared, and are now replaced by even more capable Chinese models.
In early 2018 China launched its ninth Type 815 AGI ship. This was significant in several ways, most obviously because China has built six of these ships in the previous four years and now has nine of them in service or preparing for service. With this many modern AGI ships, China is suddenly able to collect information worldwide and on a sustained basis. In less than a decade China has gone from nowhere to everywhere in offshore intelligence collection.
The Type 815s are 6,000 ton vessels that are 130 meters (418 feet) long and have a crew of about a hundred sailors plus 150 specialists and technicians. Top speed is 36 kilometers an hour and armament consists of a 37mm and two twin 25mm autocannon, which are apparently there mainly to keep minor threats away (pirates, suspicious small craft in general). There is also a landing pad and hanger for a helicopter.
These ships sport several domes protecting antennae and the ship is crammed with computers and signals processing gear. The Dongdiao class are replacing older, and much less capable, AGI type ships that entered service in the 1970s. Some of these older ships have had their electronics and other information gathering gear upgraded but are elderly and expensive to maintain. Most of the AGI work is being done by the Type 815 models.
This equipment upgrading has already taken place with the Type 815, which first appeared in 1999 as something of a prototype for a new class of AGI. The second Type 815 did not appear until 2010 and it was the same ship but with obvious differences in the type and arrangement of radars, antennae and other visible sensors. Inside the ship, there was much more powerful computers and electronics in general. In 2017 the sixth Type 815 was another major upgrade and was called the Type 815A in recognition of how extensive the upgrades had been since the first Type 815.
In 2014, before this spurt of Type 815 construction, China had about a dozen AGIs of varying sizes and ages. The Dongdiaos are the largest and most modern and are apparently going to replace most or all of the older AGIs. The Type 815s, like most AGIs worldwide, are mainly about electronic reconnaissance and collection. Just keeping track of the enemy's electronic devices has become a major military activity, especially since no one knows exactly how everyone’s electronic equipment will interact until there is a sustained period of use. Such use does not occur in peacetime when the EW equipment is used infrequently for training and testing. In addition, all electronic equipment has a unique electronic signature. Even equipment that is not broadcasting will appear a certain way to various sensors like radar or sonar. Thus a critical peacetime function is to determine what these signatures are. For this reason, navies and air forces devote a significant amount of their time tracking other nation’s capabilities. The best time to do this is during large scale naval exercises or the normal operation of coastal air defense and other military radars.
The growing military use of electronic sensors and communications (ESM or Electronic Support Measures) has made forces more capable, but also more vulnerable, especially if enemy AGIs spend a lot of quality time monitoring your operations.
As a counter to ESM scrutiny and vulnerability (to detection in combat) equipment can be disguised where possible. Signals can be varied in some circumstances. For equipment that is detected by shape and composition, like aircraft and ships, their shape and substance can be designed to minimize detection. This is the essence of the stealth technology that the United States is applying to a number of vehicles, especially aircraft. Small ships, aircraft, helicopters and vehicles loaded with sensors do most of the collecting. Low flying satellites are useful for catching signals deep inside a nation’s territory. UAVs and unmanned surface and subsurface vessels are used also, plus robotic sensors that are left on the ground or sea bottom. The collection involves more than sensors. Recording devices, foreign language interpreters and signal processing equipment also come into play.
Computers are increasingly crucial in sifting through the ocean of data swept up. Huge libraries of signals are collected, analyzed and boiled down to manageable amounts of data-which friendly troops and weapons can use. ESM has been so successful that one entire class of sensors, active sensors, has become endangered. Active sensors detect things by broadcasting a signal. When this signal bounces off something, the sensor detects the bounce back and knows something is out there. This is the basis of radar, which broadcasts microwaves, and sonar, which broadcasts sound. Because of the signal being broadcast, a passive sensor can detect it.
Passive sensors just listen. Because active sensor signals must reach an object in sufficient force to bounce something back, a vehicle carrying a passive sensor will detect a vehicle carrying an active sensor first. This is what happens you use a radar detector in your car to detect police speed trap radars. You usually have time to slow down before your illegal speed is detected by the police radar. As users of these devices well know, there is constant competition to come up with better radars and countermeasures. Passive sensors are the hot item in research and development these days, for obvious reasons. Passive sensors are nearly impossible to detect. Passive sensors can also pick a wide variety of signals. Infrared sensors can detect heat, including something as faint as body heat or the hot skin of an approaching jet aircraft.
AGI ships have lots of collecting to do and when it comes to AGI vessels, having too many of them is never enough. For the Chinese, it is different because of the growing number of Chinese claims on maritime territory. For Australia a visit by a Chinese AGI more of a threat than just a curiosity.