Facilities in the South China Sea reflect technologies otherwise hidden.

As with other maritime forces, China has been seeking to network disparate assets, and to meet that requirement, it has been establishing signal stations on islands and atolls throughout the South China Sea. These facilities, which range from communications relays to radar units, both demonstrate Chinas expanding regional reach and provide a rare glimpse of the countrys military electronics technologies.

China has been actively expanding south from Hainan Island since 1974 when it seized the Paracel Islands from the Vietnamese, and its activities continued in the 1990s with construction on several Spratley Islands reefs. Locations of Chinese military electronics on the mainland are largely hidden, and any photographs are classified. But, facilities on the South China Sea islands and reefs place this technology out in the open.

Based on electronics and facilities observed, Woody Island in the Paracels and Fiery Cross Island in the Spratleys seem to be the main control links to Chinas South Fleet Guangzhou headquarters. Other armed Chinese islands or reefs are linked via satellite communications and radio to the local and fleet commanders. The electronics and combat systems of the Chinese aircraft, warships and paramilitary ships greatly augment the island-based electronics.

The only electronic systems directly off the south China coast are ones that involve offshore naval operations. A large over-the-horizon (OTH) backscatter (OTH-B) radar faces south near the southern coast of China. In the 1970s, the experimental OTH radar had a 2,300-meter antenna and could pick up surface ships at 250 kilometers. A series of technical papers describing a skyway OTH radar in the early 1990s leads to the conclusion that operational deployment would have been in that period.

The fact that Guangzhou is the headquarters of the South China Fleet indicates a major complex of tactical and strategic space and land-based communication and long-range radars in that area. They would be focused south into the South China Sea.

Radio beacon navigation–differential global positioning system (GPS), or RBN-DGPS, are located at the southern ports of Zhanjiang, Fangcheng and Luyu. DGPS manufactured by Communication Systems International can be accurate to within 5 to 10 meters with a 300-kilometer range. The vessel traffic service (VTS) is located at Zhanjiang. Western imported technology is an integral part of these electronic systems because the DGPS is Australian and VTS is from Lockheed Martin in Syracuse, New York.

Although appearing to be a tourist island of native tribes and small villages, Hainan Island features an embedded, but nearly invisible, strong military electronic infrastructure. The emergency landing of a U.S. Navy EP-3C at Lingshui airfield in 2001 was a peek into this. Mainland Chinese governments prior to World War II minimally touched Hainan, although there was a naval station at "Hoihow" (now Haikou) in the early 1900s. During the seven-year Japanese occupation in World War II, the island had an extensive military and industrial buildup. This included large coal and ore mines as well as the first railroads connecting to a new major Japanese submarine base at Yulin. Although today the locations of Hainan long-range air search sites are classified, Japan had sites at Yulin, Basuo and Haikou in 1944.

Work started in the late 1970s on three high-power radio navigation aids in south China, but they were not online until 1983. Modern RBN-DGPS navigation aids are located at Sanya, Haikou and Haifou. The VTS with radar and a computer tracking/control station are located on the west coast at Dong Fang (formerly Basuo) and in Haikou. The Haikou facility has one local and three remote dual X-band radars, a local and remote very high frequency (VHF) communication system and a remote VHF direction finder. This vessel traffic management system controls traffic in the Qiongzhou Channel between Hainan and the mainland. A digital GPS beacon station of 295 kilohertz was activated in 1999 at Sanya, and two more followed at Yangpu and Baohujiao.

Hainan certainly has one or more major electronics intelligence (ELINT) stations, but references are usually vague or disagree in details. Because of the continuing threat of conflict with Vietnam, a major ELINT site probably was built on mountaintops on southwest Hainan. The most detailed description available discusses a large facility at Lingshui air base on the southeast coast. This complex reportedly was established in 1968 and greatly expanded in 1995, with about 1,000 signal analysts located there. A large satellite downlink facility with an associated computer complex and links to Beijing is at Changcheng. It is allegedly a State Oceanographic Agency site for weather data connected to a Chinese weather outpost in Antarctica.

The first high-power low frequency (LF) station was built on Hainan in 1965. The large submarine base at Yulin, which is not on most maps anymore, has extensive communication links for the 3rd Submarine Flotilla headquarters. These include very low frequency (VLF) communications to submarines and surface ships in the South China Sea area. This may have been one of the first Chinese VLF stations, since construction activities had been reported from 1969 until 1982. Even navigation charts showing Yulin stated it was “closed to foreign commercial vessels” due to World War II mines in the approach.

The Paracel Islands were occupied by Vietnam until China seized them in occupation assaults supported by naval warships in 1974. A 1980s photograph of a naval base in the Paracels shows a huge multiantenna array of 16 yagi antennas aimed skyward. Each antenna consisted of 8 yagi cross arms. This probable VHF monstrous array is not described or named in open literature references. One publication with this illustration described it as a satellite communication antenna, while another stated it was a Moon early warning radar. The antenna appears similar to a smaller truck-mounted 400-megahertz wind-tracking yagi radar designated Type 701 by China. This may be a meteorological weather antenna that is located on Woody Island.

Woody Island is a classic example of how a crude outpost can grow over time into a significant threat equivalent to an unsinkable aircraft carrier. A helicopter landing pad was built within one year, and this would have required ground-to-air links—probably the Ote Alenia imported radios used throughout China. In 1990, China constructed a 1,200-foot runway on Woody Island that was suitable for jet fighter aircraft. In 1998, the runway was extended to 7,300 feet and finally to 8,100 feet in 1990 for heavier aircraft such as H-6 bombers or large transports for resupply. This requires the Chinese Type 791 X-band precision approach radar (PAR), which is based on the old Soviet Two Spot RSP-7. It has a 20-degree-azimuth and six-degree-elevation antenna beam pattern and a cone-shape antenna for VHF and ultrahigh frequency (UHF) air communications. A larger pier and airplane hangers augmented the islands single jetty, and fuel storage has been added.
In June 2001, HY-2 antiship cruise missiles appeared. They would require a long-range surface-search radar to detect surface ship targets. In mid-1995, a new signals intelligence (SIGINT) station entered service on Rocky Island, which is near Woody Island. This station could support air or surface warning for air missions or ship targeting, especially because Rocky Island has the highest peak in the Paracel Islands.

The largest island in the Paracels is Pattle Island, which had a weather station when Vietnam lost it in 1974. The port facilities on Duncan Island, the second largest island, are being enlarged, which would indicate increased military construction and electronic equipment. Drummond Island, the site of a naval battle in 1974, is not known to have any buildings or electronic equipment.

The only radio beacon south of Hainan is at Robert Island, which is only 500 meters long. There are no modern DGPS navigation beacons in the Paracels, so this must be an older type installed in the late 1970s.

Another disputed island group claimed by China is the Spratley Islands. Popular opinion tends to state that the Spratley Islands largely were uninhabited until the recent construction. In fact, during World War II, Japan built bases on Danger Reef, Tizard Bank and Namyit Island, which are occupied by Vietnam and the Philippines today.

In the 1980s, cruises in the Spratleys by nonmilitary fishermen and later ocean research ships soon were followed by Chinese warship visits. In 1988-1989, several dozen Chinese warships conducted large naval exercises coinciding with occupation of reefs in the Spratleys. In November 1990, China completed a lengthy hydrological survey with search ships in the Spratleys. In the 1990s, construction began on crude huts and octagonal wooden structures on wooden pilings. These were called “typhoon shelters for fishermen” by the Beijing government.

In 1995, China built its first structures on one point of the circular Mischief Reef. In October 1998, these were expanded with three additional clusters of more octagonal wooden structures. Each cluster of structures has a 2.5-meter satellite communication dish aimed skyward. The northern and southern clusters had two-story cement buildings constructed, which resembled forts with the usual satellite communication and high frequency (HF) whip antennas. The southern building was about 36 meters long, and the northern building was 122 meters long. Two years later, major electronic and weapon emplacements were added to the smaller northern building. Additional piers, a helicopter pad and several anti-aircraft guns were added along with an unidentified missile weapon system. The new weapon system could be HY-2 or newer C-801 anti-surface-ship cruise missiles. A white rectangular antenna was placed on top of the building control tower. It resembles a navy navigation radar, which would have a range of about 25 miles around the semi-submerged island. It could be an imported Racal Decca 1290 Arpa radar or a Chinese Model 756 navigation radar with a dual X-band and S-band antenna.

After civilian and scientific vessels reconnoitered the area in October 1987, China seized Fiery Cross Island in March 1988. It sits in the eastern Spratleys deep in Philippine waters. A photo of a 200-foot-long cement building on Fiery Cross Island shows a standard naval HF yagi radar antenna based on the Soviet Knife Rest. The Chinese copy, designated Bean Sticks, operates in the 70- to 73-megahertz frequencies with a range of about 180 kilometers.

Two other small electronic countermeasures (ECM) radomes on the building appear similar to the RWS-1 mounted on navy destroyers. Land-based ECM domes such as these are not identified in references. Several whip communication antennas and taller mast antennas also are on the roof.

Chinese radios may be connected to different antennas for different needs. For example, R-series HF radios use a 4-meter whip for up to 25-kilometer communications, and they use an 11-meter mast for ranges out to 40 kilometers. A long wire runs from a mast on one end of the building to the ground, which would be an HF long-line radio antenna. A probable radio would be the large 73-kilogram SR 109 synthesized receiver with a band from 10 kilohertz to 30 megahertz. It is suitable for radio signal surveillance and long-range distance communications. In addition to two roof-mounted 2.5-meter satellite communications dishes, there is a large 4-meter dish mounted on a large pedestal. This probably is a meteorological weather antenna.

On Johnson South Reef, four octagonal huts initially were built on wooden pilings. By 1989 there were two round cement towers on the ends of a two-story white rectangular building on a cement base. At one end is a 2.5-meter satellite communications antenna adjacent to an 8-foot mast antenna, with two more tall mast antennas on the roof. Chigua Island has an identical building structure with a wooden barracks adding greatly increased manning space. Subi Reef in 1997 had the typical wooden barracks structure and a two-story building with one satellite communications antenna. Two unusual features are a huge round helicopter landing pad and a sturdy cement bridge with cement arches connecting it to the headquarters building. These are both unique to Subi Reef.

Most of the Chinese outposts have a small tower on top of the two-story cement buildings that are the electronics centers for communications, ELINT and radars. This would be where the duty officer would stand watches. Many of these complexes retain small wooden huts on the end of jetties, which would be a good location for noisy power generators and hazardous toxic materials like fuel barrels for the power sources. Most outposts have helicopter landing pads and small- to medium-size piers to receive personnel or logistic supplies via ships.

On the far western edge of the South China Sea is a Chinese electronic activity aimed at India. In 1992, construction began on a SIGINT station on Coco Island near the Indian navys large base on Andaman Island.