Project 2319 Tianbo [Sky Wave]
Over-the-Horizon Backscatter Radar [OTH-B]
China aspires to use Over-the-Horizon (OTH) sky-wave radar systems to target aircraft carriers. These systems could be used in an early warning capacity. China has also deployed surface-wave radars. Sky wave over the radar has a range of 1000 to 4000 km. The range of ground-wave over-the-horizon radar is short, but it can monitor the area that can not be covered by sky-wave over-the-horizon radar. China's sky-wave system radar system can detect U.S. aircraft and ships at a long distance from the coastline of the country.
Sky wave radar and ground wave radar collectively referred to as OTHR. OTHR has two basic types: the use of ionospheric shortwave reflection effect so that radio waves to the distant radar, known as sky-wave over-the-horizon radar; the use of longwave, medium and shortwave diffraction effect in the Earth's surface so that radio waves Radar spread along the curve, known as the ground wave over-the-horizon radar. OTHR is one of the technologies that Western countries have imposed on China's major blockades and embargoes. The former Soviet Union had only given some guidance to China theoretically, and China's own world of radar has truly reached its combat readiness level based entirely on China itself.
In November 2008, Sean O'Connor posted a great analysis of the OTH radar system and its role in an ASBM program on his IMINT & Analysis website. Andrew S. Erickson and David D. Yang (Naval War College and RAND), Mark Stokes (Project 2049 Institute), Eric Hagt and Matthew Durnin (China Security), and Tony Capaccio (Bloomberg) also have addressed the OTH radar cueing issue.
Interferometry does increase the total signal collected, but its primary purpose is to vastly increase the resolution through a process called Aperture synthesis. This technique works by superposing (interfering) the signal waves from the different telescopes on the principle that waves that coincide with the same phase will add to each other while two waves that have opposite phases will cancel each other out. This creates a combined telescope that is equivalent in resolution (though not in sensitivity) to a single antenna whose diameter is equal to the spacing of the antennas furthest apart in the array. With the Chinese NOSS satellite trio flying in fixed formation, radar interferometry can be used to increase the resolution of the Chinese NOSS satellite receivers. The HF emitters are on the ground, but the receivers can be either on the ground or in space.
|Site 3||transmitter||TBD SCS||TBD SCS|
|Site 3||receiver||TBD SCS||TBD SCS|
In January 2016 it was reported that China Tianbo over-the-horizon radar had entered the end of the joint test, is about to be delivered for use, and set up the corresponding Tianbo Brigade. This shows that the Chinese military is vigorously developing the Tianjun. At present, it is directly responsible for the headquarters. After the formation of the system, it will be handed over to the Air Force. This is also a major component of China's military reform. Air and space combat weapons are becoming an important equipment for the development of the Chinese Air Force and the Rocket Army. Henri Kenhmann of EastPedulum reported 18 January 2017 that "The satellite images as of December 31, 2016 show that China has started the construction of a second trans-horizon radar (OTH-B), like the first one that was built in the center of the country and able to spot its targets over a distance of more than 3,000 km..... unlike the first Chinese OTH-B radar that targets the wide area between the coast East of China to the second chain of islands, that is to say, to Guam, where is the largest US military base in the Western Pacific, this second trans-horizon radar covers the entire peninsula of Korea, and a large majority of Japan, from Hokkaido Island in the north to Okinawa Island in the south."
While protesting the deployment of the THAAD missile defense system in South Korea -- calling it a threat to its national security -- Chinese state media reported 15 March 2017 that China had installed another over-the-horizon Tianbo radar in Inner Mongolia. Its main objective was detecting an opponent's missile launch and the localization of an intercontinental ballistic missile. Within a minute, Tianbo can confirm the target to strike, as it detects the launched missile.
The over-the-horizon radar, which was installed in January 2017, has a range of about three-thousand kilometers, enabling it to detect not only South Korea and Japan but even the Western Pacific. That's far bigger than the coverage of THAAD's X-band Radar,.. which has a range of 600 to 800 kilometers. According to the Chinese media, the Tianbo radar can also detect U.S. F-35B stealth fighters deployed at the Iwakuni base in Japan. It can also monitor aircraft carriers and warships within its radius.
The receiver for the second site is located at Darhan Muminggan, Baotou, Inner Mongolia, China. Based on the configuration of the first site, the transmitter for the second site might be expected to be found in the vicinit of Naomugeng Sumu, Siziwang, Ulanqab, Inner Mongolia. There is some sort of larger military-type tower at this location, which is at the intersection of two highways in an area that is otherwise the epitome of a trackless wasteland.
China may plan to deployed an Over-the-Horizon Backscatter Radar [OTH-B] to provide surveillance of the South China Sea. The precise location of this facility remained unclear.
A large over-the-horizon (OTH) backscatter (OTH-B) radar was said to face south near the southern coast of China. A series of technical papers describing a skyway OTH radar in the early 1990s led to the conclusion that initial testing could have been in that period. Several technical papers appeared in Western publications concerning OTH-B systems, including:
- Zhao Shuqing, Liu Yongtan and Duan Fengzeng (1990) Digital beamforming in the OTH radar ICSP-90 Beijing, 655-656.
- Jiao Peinan (1991) A new method of track processing in HF skywave OTH-B radar ACTA CIE 19, 1, Jan 91, 1-6.
- Zhao Shuqing and Liu Yongtan (1991) Frequency domain digital beamforming in the OTH radar SEE 13, 1, Jan 91, 47-51.
- Zhou Wenyu and Mao Xu (1991) Bistatic FMCW OTH-B experimental radar ICR-91 CIE, 138-142.
- Wang Jiliang and Duan Fengzeng (1993) Application of maximum entropy in angular superresolution of OTH radar SEE 15, 10, Oct 93, 21-30.
In 1982, Bao Yang and Jiao Peinan presided over the successful development of China's first "pulse system sky wave over-the-horizon test radar" (112-1 radar), successfully detected aircraft targets in strong clutter at ranges of 900~1500km, which made China the third country to independently master this technology. The radar won the second prize of the National Science and Technology Progress Award in 1985. In 1998, China's first "frequency-modulated continuous wave system sky-wave over-the-horizon test radar system" successfully detected aircraft targets at ranges of nearly 2000km and independently tracked multiple targets. The key technology of the radar had reached the advanced technology level of today's international radar systems of its kind. In January 1999, the test radar system passed the national appraisal.
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