This post is also available in: עברית (Hebrew)
China is a rising power in today’s reality, there’s no doubt about that. We in i-HLS.com have wrote extensively about the country’s efforts of arming itself with the best weapons it can manufacture, and also about the Chinese leader talking about becoming more and more technological. The next step China will be making is related to terrain dominance, specifically of the South China Sea.
China has begun building a multi-sensor system for obtaining constant data on the precise location of surface and submarine vessels in the South China Sea. Surface surveillance would be carried out by a constellation of ten remote sensing satellites so that the South China Sea is under constant surveillance. Satellites at an altitude of 600 kilometers would be equipped with SAR (synthetic aperture radar) and digital cameras.
A typical SAR can produce photo quality images at different resolutions. At medium resolution (3 meters) the radar covers an area 40 x 40 kilometers. Low resolution (20 meters) covers 100 x 100 kilometers. This takes care of surface ships, and diesel-electric subs when surfaced. Since 2010 China has been experimenting with such an array, using three satellites moving in formation over the western Pacific.
According to strategypage.com, China announced that the first South China Sea satellite will be launched in 2019 and all will be in orbit by 2025. By 2030 the Chinese Navy will have 260 ships, 30 percent more than the American fleet. Those satellites and the rest of the sensors will add to that numerical superiority and make the South China Sea a very dangerous place for anyone the Chinese do not want there.
To make this surveillance system work China is using or adapting a lot of existing technologies. For underwater surveillance China is installing a network of underwater sensors similar to the American Cold War era American SOSUS (SOund SUrveillance System).
The original SOCUS consisted of several different networks. On the continental shelf areas bordering the North Atlantic was the CAESAR network. In the North Pacific there was COLOSSUS plus a few sensors in the Indian Ocean and a few other places that no one would talk about. The underwater passive sonars listened to everything and sent their data via cable to land stations. From there it was sent back to a central processing facility, often via satellite link.
SOSUS was accurate enough to locate a submarine within a circle no wider than 100 kilometers. That’s a large area, but depending on the quality of the contact, the circle might be reduced up to ten kilometers. The major drawback of the system was that it did not cover deep water areas more than 500 kilometers from the edge of the continental shelf. This is not a problem for the Chinese system, as most of the South China Sea is shallow and similar to coastal waters.
South Korea began building a coastal SOSUS system after 2010 to deal with North Korea (and, by implication, Chinese) submarines off their coasts.