Taiwan's new USD1.38 billion long-range radar, the Surveillance Radar Programme (SRP), has been fully operational for about a year. However, China may already have the ability to interfere with its signals, according to sources in Taiwan and Washington.
Development of the SRP, which is intended to provide Taiwan with a form of "strategic depth" by providing very early warning of Chinese long-range air and missile activity, dates back to 2000 when its sale was approved by the Clinton Administration. Following repeated delays and cost overruns, Taiwanese officials revealed that it was operational in February 2013.
Taiwan's SRP is based on the Raytheon AN/FPS-115 Pave Paws large phased array radar (LPAR). Located at Loshan Mountain in Hsinchu County, Taiwan, it is reported to have a range of 5,000 km (3,100 n miles), and it is able to track a golf ball-sized target out to 3,000 km. Taiwanese officials revealed that it was able to track North Korea's 12 December 2013 satellite launch, which was about 1,800 km from Taiwan.
Satellite imagery obtained by IHS Jane's shows that China has built a large phased array radar north of Huian in Fujian Province approximately 240 km northwest of Taiwan's SRP. The Chinese radar array, constructed sometime before 2008, is similar in size to the SRP. It appears to employ a fixed array boresighted along an azimuth of approximately 144 degrees. With an assumed coverage of +/-60 degrees in azimuth, the Chinese LPAR is theoretically capable of monitoring the entire Taiwan Strait region, as well as the southern approaches to the South China Sea.
Like Taiwan's radar, the Chinese radar is located on a hill top. By matching the pulse repetition frequency (PRF) of Taiwan's radar signals the Chinese radar can interfere with the ability of the SRP to track targets. Radar pulses can be made to be very complex to avoid such interference but China can employ electronic intelligence (ELINT) systems to determine the SRP's signals.
According to a US source, the US Navy has to space its large Aegis phased array radars within a naval battlegroup in order to avoid radar interference.
A senior political source in Taiwan confirmed to IHS Jane's that China's radar has "interfered" with the SRP.
This interference is noteworthy given the LPAR's design. Two other LPARs in eastern China feature very different arrays and are believed to serve in a ballistic missile early warning or anti-satellite tracking capacity.
The different design of the LPAR at Huian - and the reports from Taiwan of interference - indicate that electronic interference represents a possible design driver for the new array that could possibly influence its location. The postulated 120 degree coverage arc of the LPAR also means it could interfere with other Taiwanese sensor systems deployed along the island's western side.
Chinese radar coverage of the Taiwan Strait region is robust, with multiple radar complexes monitoring airspace and sea traffic. This eliminates the requirement for an LPAR to solely serve as an additional monitoring station. However, given its ability to monitor far larger regions than any other deployed radar system in the area, airspace monitoring is believed to represent a major portion of the new LPAR's mission.
The LPAR could also be used to monitor air and space activity well beyond Taiwan if the People's Liberation Army attacked the island. Assuming that Chinese forces disable or destroy Taiwan's SRP, the LPAR's role would then be to provide long-range coverage extending north to Japan and to the Philippines.
Lastly, China also has a political motivation to match Taiwan's huge investment in an LPAR. By doing so, Beijing demonstrates that it can win the arms race with Taipei: a move that could be part of a wider propaganda campaign to demoralise Taiwan and increase the pressure for unification.