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Weapons of Mass Destruction (WMD)


Over-The-Horizon Surface Wave Radar (HFSWR)

System 1Wenzhou, Zhejiang27°46'10.00" N 120°44'44.34" E
TX site 2 transmitters, 2x Log Periodic Antenna Arrays (LPAA).
RX site 1x Monopole antenna array.

System 2Fuzhou, Fujian 22°55'26.51"N 116°13'32.07" E
TX site 2 transmitters, 2x Log Periodic Antennas (LPA, single antenna).
This is the only transmitter antenna configuration in the radar network, only one LPA is used per one transmitter.
RX site 1x Monopole antenna array.

System 3 Zhangpu, Fujian25°47'25.10"N 119°37'08.79" E
TX site 2 transmitters, 2x Log Periodic Antenna Arrays (LPAA).
RX site 1x Monopole antenna array.

System 4 Guangdong24°04'56.97" N 117°54'06.38" E
TX site 2 transmitters, 2x Log Periodic Antenna Arrays (LPAA).
RX site 1x Monopole antenna array.
Construction took place in 2014 to relocate the Control and RX sites that are close to a nearby developing industrial park.



Over-The-Horizon Surface Wave Radar (HFSWR)The relatively shorter range does not mean that the high-frequency ground-wave over-the-horizon radar is not as important as the sky-wave over-the-horizon radar. On the contrary, due to the nature of the sky-wave over-the-horizon radar, there must be a short-range blind zone of hundreds of kilometers, which makes it impossible to form effective coverage of the coastal area. The high-frequency ground wave over-the-horizon radar with a distance of hundreds of kilometers is the first choice for covering this area. From this point of view, the two are complementary to each other and constitute an important part of China's surveillance of the sea's visual line of sight.

The earliest imagery depicting one of these systems was captured in 2003, suggesting that the array has been a relatively recent deployment. Each OTH-SW system is bistatic. Normally, all the Chinese OTH-SW radars will be up at the same time using different frequencies, and their OTH-B radars will be operating simultaneously. Transmitter beaming direction is determined by measuring TX LPAA pointing direction at each TX site and except for site 2 with only 1 transmitting direction (60 degrees coverage sector), the coverage for rest of the sites are a comination of 2x adjacent 60-degree sectors (120 degrees) which result from the use of 2 independant LPAA at the transmitter site.

A relatively new PLA Air Force radar brigade – the 95980 Unit – operates the OTH radar system. The PLAAF “Skywave Brigade" is situated in the southern edge of Xiangfan, Hubei province, or specifically in Yingpan Village in the Xiangcheng District. A guarded underground facility, to the east of the village, could house the OTH surveillance and warning system. The PLAAF radar brigade has at least six subordinate elements (fendui). Two are near Xiangfan: the 52nd Element in the Zaoyang Municipal District and the 53rd in Nanzhang County.

  • 61st Element based near Xitangqiao Village ;
  • 64th Element located near Fuqing,
  • 66th Element near Jinjiang, Fujian province Sanshan Village; and
  • 67th Element near Wenlin City Shitang Village .

On 09 January 2019, China's famous radar expert, professor of Harbin Institute of Technology, and academician of the two academies Liu Yongtan won the 2018 National Supreme Science and Technology Award. The winning project is the domestic high-frequency ground wave detection radar. This radar is said to have successfully detected stealth targets. Compared with traditional radar, HF ground wave radar has a long detection range and a wide coverage. A radar is equivalent to dozens of traditional system radars, especially its ability to exceed the line of sight and anti-stealth. In the modern defense system, the value is high.

China has developed an advanced compact size maritime radar which can maintain constant surveillance over an area of the size of India, media reported on 09 January 2019 [note that the claim is not that a single station can cover such a large area - 3.3 M square kilometres / 1.3 M square miiles - but that the network as a whole could cover such an area]. The domestically-developed radar system will enable the Chinese navy to fully monitor China’s seas and spot incoming threats from enemy ships, aircraft and missiles much earlier than the existing technology, the Hong Kong-based South China Morning Post reported, quoting the scientist who took part in China’s radar program.

China's maritime early warning radar system is immune to "radar killer" missiles and is capable of detecting stealth aircraft, according to its developer in a June 2019 interview with media. The maritime radar system, developed by a team led by Chinese academician Liu Yongtan, can detect naval and aerial hostiles hundreds of kilometers away under any weather condition.

The accounts of this radar are more than a little bit jumbled. Many refer to an "Over-the-Horizon (OTH)" radar, and one even mentions a "ship-based OTH" system. OTH radars come in various forms, and in the West the most commonly encountered radar is an OTH Backscatter radar. The HF over-the-horizon radar (OTHR) is based on the skywave or ground-wave propagation mode. The skywave OTHR uses the ionosphere to reflect its waves back to the Earth, and can provide radar coverage at distances of about 100–3500 km to monitor aircraft, missile launches, nuclear explosions, ships, etc.

China had reportedly been working on OTH-B since 1986. By 2017, it had at least one OTH-B radar in active use and another under construction. At that time, it did not have an OTH-B radar covering the South China Sea, but was likely to have one eventually. In coming years, China will almost certainly desire and achieve a set of OTH-B radars covering its entire maritime periphery.

However, Liu's radar does not seem to be an OTH-B. Other accounts report that the signals from the "radar travel along the sea surface" and "the system can detect naval and aerial hostiles hundreds of kilometers away". Also noted is the "compact size" of the radar. These descriptions are consistent with a high frequency surface wave radar (HFSWR). This ground-wave OTHR makes use of the ground propagation, and can detect the targets beyond the horizon to distances of hundreds of kilometers. Considering the practical radar resolution that depends on the width of the antenna beam and the range to the target, this OTHR is most useful for providing early warnings of low-flying aircraft, ships, sea-skimming missiles, etc.

The new radar features high frequency electromagnetic waves that have long wavelengths and wide beams, Liu said in an interview with the Naval and Merchant Ships magazine published June 2019. According to Liu, the radar had greatly increased the range of area that the Peoples’ Liberation Army (PLA) could monitor. “Relying on traditional technologies, our surveillance and monitoring could only cover about 20 per cent of our maritime territory. With the new system, we can cover the whole area,” he said.

While electromagnetic waves emitted by a normal radar travel in straight lines and, since the Earth is round, cannot help see what is beyond the horizon, the high frequency ones used by Liu's radar travel along the sea surface, and he said this makes it possible to detect and monitor vessels and aircraft beyond visual range.

The long wavelengths used by the system mean it could also detect stealth aircraft, Liu said. This is because current stealth aircraft are mainly designed to hide from microwaves and not waves of longer wavelengths, experts said. The radar can also avoid attacks from anti-radiation missiles, thanks to the waves' wide beams, because such missiles cannot carry antenna large enough (to track them), Liu said.

Wei Dongxu, a Beijing-based military analyst, told the Global Times on 10 June 2019 that stealth aircraft and anti-radiation missiles are two killers of radars. Normal radars cannot detect stealth aircraft, and they would have to destroy radars first to let non-stealth aircraft in safely. An anti-radiation missile tracks an electromagnetic wave source, so it is the natural enemy of radars, Wei explained. Liu's radar has a much higher chance of survival in a potential attack and can provide an umbrella for a sneak attack from stealth aircraft, Wei said.

A land-based version of the system can detect naval and aerial hostiles hundreds of kilometers away, which helps expand China's maritime early warning and defense depth, Liu said. Variants of the system can also be equipped on ships, providing them with early warning capabilities in the high seas with a much farther detection range, he said.

In January 2019, Liu received the 2018 State Preeminent Science and Technology Award — the nation's highest scientific award with 8 million yuan ($1.17 million) prize — for his contributions to the development of the radar system. Military experts said that Liu was awarded because he substantially enhanced the China's capability to resist external threats, as the radar system is dubbed a "country's first line of defense."

China began development of HF ground wave OTH sensors in November 1967. A group led by Deputy Director of the Space and Missile Industry Qian Xuesen was assigned the responsibility of developing a ground wave OTH sensor able to detect targets at 250 kilometers. The radar was to provide targeting data for their embryonic anti-ship cruise missile program. In the 1970s, an experimental ground wave OTH radar, with an antenna length of 2300 meters, was deployed. Foreign export restrictions, however, prevented China from obtaining technology which was needed for further improvements.

A Chinese blogger posted an article in November 2007 that highlighted a PLA Air Force (PLAAF) “Skywave Brigade”. The post first appeared on the Wangchao bulletin board website and has been reposted hundreds of times since then. The author asserts that the brigade operates China’s first strategic early warning system in over 20 years, when a brigade operated a missile early warning system in the area of Xuanhua, north of Beijing. The missile early warning radar has been dismantled. The author, careful to avoid censors, uses Pinyin abbreviations for locations of the transmitter and receiver and names of the commander and political commissar of the PLAAF radar brigade. He also notes a requirement for additional sites in Fujian and presumably other locations along the east coast for measuring the ionosphere.

Transmitter beaming direction is determined by measuring transmitter [TX] log-periodic antenna array [LPAA] pointing direction at each TX site and except for site 2 with only 1 transmitting direction (60 degrees coverage sector shown), the coverage for rest of the sites are a comination of 2x adjacent 60-degree sectors (120 degrees) which result from the use of 2 independant LPAA at the transmitter site.

Over-The-Horizon Surface Wave Radar (HFSWR) High-frequency ground wave radar uses short-wave (3~30MHz) to transmit small attenuation on the surface of conductive ocean surface. It uses vertical polarized antenna to radiate electric waves, which can detect ships, airplanes, icebergs and below below sea level line of sight. Moving targets such as missiles can reach a distance of more than 300km.

HF radars have been used since the 1960s. When located at coastal areas and transmitting vertical polarization, HF radar systems may exploit the high conductivity of sea water to propagate their signals (e.g., in a surface-wave mode) well beyond the visible or microwave-radar horizon. Although HF surface-wave radar (HFSWR) was initially considered for detecting military targets beyond the horizon (e.g., ships, low-flying aircraft or missiles), HFSWR also found widespread acceptance and use in the mapping of sea surface currents and the monitoring of sea state (e.g., waveheights). The radar echo used in these sea mapping/monitoring applications comes from Bragg scatter by ocean surface waves that are about half the radar wavelength, traveling toward and away from the radar.

Conventional radars determine target bearing by forming and scanning narrow beams using radar antennas. One procedure for sea mapping/monitoring using HFSWR has been to use a transmit antenna system that floodlights a large bearing sector of the sea (e.g., 60°) with illumination. A separate receive phased-array then forms a narrow beam that is scanned across the illuminated sector using software algorithms after signal digitization. The beamwidth (i.e., angular resolution) depends on the length of the antenna aperture, being proportional in radians to the wavelength divided by the array length. Because the wavelength at HF may be almost 1000 times greater than for microwave radars, the length of an HF array may be hundreds of meters long. While such radars were built and operated in the 1960s, antenna size and related cost impeded widespread acceptance. Coastal locations are valuable land for other public and private use, and suitable locations for large antennas as coastal structures are difficult to obtain.

Unlike military high-frequency over-the-horizon radars, which operate several kilometers of antenna arrays, Barrick creatively uses a set of cross-ring/monopole antennas (three receiving channels) to obtain large-area ocean current distribution information. Compact radar antenna technology greatly reduces the cost of ground wave radar acquisition and installation.

Surface wave radar systems, in particular high frequency surface wave radar (HFSWR) systems, have recently been developed to overcome the line-of-sight limitation of microwave radar systems. High frequency surface wave radar (HFSWR) has been employed for more than three decades for detecting and tracking maritime targets beyond the horizon, and particularly to the boundaries of the economic exclusion zone (EEZ), for civilian and military purposes. In HFSWR installations, it is desirable to reduce the physical size of the receiving array of the radar. From an implementation point of view this can significantly reduce the physical extent of the radar site and thereby increase the number of location options. Simply employing a smaller receiving array, however, may compromise the overall performance, and, in particular, the resolution of the radar.

HFSWR exploits a phenomenon known as a Norton wave propagation whereby a vertically polarised electromagnetic signal propagates efficiently as a surface wave along a conducting surface. HFSWR systems operate from coastal installations, with the ocean providing the conducting surface. The transmitted signal follows the curved ocean surface, and a system can detect objects beyond the visible horizon, with a range of the order of 200 km. The successful detection of a target by a surface wave radar system traditionally involves compromises between a number of factors, including propagation losses, target radar cross-section, ambient noise, man-made interference, and signal-related clutter.

Raytheon Canada and the Canadian military developed such radar, designated the HF-SWR-503. This is an oceanic surveillance system for monitoring such illegal activities as drug trafficking, smuggling, piracy, illicit fishing and illegal immigration. In addition, it may be used for tracking icebergs, environmental protection, resource protection, sovereignty monitoring and remote sensing of ocean surface currents and winds as well as assist in search and rescue operations.

It consisted of an array of monopoles 660 meters (2,165 feet) long, with the monopoles spaced at about 50 meters (164 feet), corresponding to half the wavelength of the radar's 3 MHz operating band. The array has a field of view of 120 degrees and can track targets to the limit of Canada's 370 kilometer (200 nautical miles) oceanic economic exclusion zone. It can obtain positions accurate to within hundreds of meters. Raytheon stated that a similar array could be used to track low-flying cruise missiles if it operated at a frequency of 15 to 20 MHz.

A German OTH-SW application with more civil use is the WERA radar. The WERA system is a shore based remote sensing system to monitor ocean surface currents, waves and wind direction.

Target detection is one of the main functions of HF ground wave radar. In the military field, HF ground wave radar is mainly aimed at long-range target early warning capability along the purely militarized way. Its typical representative is the British "supervisor" system. Russia's "Sunflower" system and Canada's SWR-503 system. It is characterized by wide frequency band, large transmit power (up to hundreds of kilowatts), and large receiving antenna array (hundreds of meters to several kilometers). The single radar has strong target detection capability. The disadvantages of this type of equipment are that the system is too complicated, the development cost is high, the mobility and concealment are poor, and strong security conditions are required, which makes it difficult to promote deployment on a large scale.

In "Deployment of a rapidly re-deployable HF radar concept", T. M. Blake, Electro-Magnetic Remote Sensing (EMRS) Defence Technology Centre (DTC) 1st Annual Technical Conference 20-21st May 2004, there is disclosed an HF surface wave radar system, comprising a linear array of separate spaced apart (7 meter spacing) receive antenna elements, each element being a vertical active antenna, 2.5 meters long. Each element includes a receiver for processing received signals. The elements are connected in a daisy chain arrangement by digital data link cables to a control center, located in a van. A corresponding transmit antenna array is also provided. The system is taken to a site in a disassembled state in the van, and then rapidly assembled by two technicians by placing the elements in the ground in spaced apart positions, and connecting them together by the data link cables.

By placing receivers at the base of the elements, difficulties arise in that the elements have to be synchronised in time, frequency and phase in order that the radar system function accurately. Further their position relative to one another needs to be known accurately, but since they are positioned by hand by technicians without scientific instruments to permit accurate placement, (desirably to within 0.1 meters) this is a further problem. While a wide variety of HF antenna arrays are known comprising a multiplicity of antenna elements, such elements are normally fixedly mounted together in a framework or other mounting arrangement--this would not be suitable for a rapidly deployable system, in particular where the elements are spaced a long distance apart.

Since the 1970s, the relevant domestic units have started the development of high-frequency ground wave radar, including Wuhan University and Xi'an University of Electronic Science and Technology. Among them, the OSMAR series of high-frequency ground wave radar of Wuhan University has entered the practical stage. The Harbin Institute of Technology, where Liu Yongtan is a member, is also a High-frequency ground wave radar research center.

The development of high-frequency ground wave radar was first started by Harbin Institute of Technology in the early 1980s, and a high-frequency ground wave radar station was built at Harbin Institute of Technology Weihai Campus for testing experiments, in radar systems, target detection, Long-term work has been accumulated in anti-jamming, radar antenna testing, and digital transformation of radar systems, and a lot of experience and results have been achieved. The portable high-frequency ground wave radar OSMAR-S developed by Wuhan University with compact antenna has been successfully developed and has been put into actual operation observation, filling the domestic gap.

LD-JHC300 surface-wave over-the-horizon radar LD-JHC300 surface-wave over-the-horizon radar LD-JHC300 surface-wave over-the-horizon radar LD-JHC300 surface-wave over-the-horizon radar

In the early spring of 1982, Liu Yongtan made a special trip to Beijing to report to the then leader of the pre-research department of the Ministry of Aerospace Industry, and introduced the development of the radar of the new system of the developed countries at that time, and talked about his bold ideas. The leader of the pre-research department listened very seriously, and supported the idea of Liu Yongtan on the spot. He hoped that he would quickly organize a scientific and technological research force and develop the new system radar at an early date. After receiving support, Liu Yongtan immediately carried out careful planning and preparation. Based on the latest technical information of radars in the world at that time, he used his new scientific research results obtained abroad, and used unique signal and digital processing technologies to propose a plan for the development of a new Chinese radar system.

After 10 months of continuous hard work, a more than 200,000-character "Overall Scheme Demonstration Report for the New System Radar" was born. In the summer of 1983, the former Science and Technology Committee of the Ministry of Aerospace Industry held a program review meeting to conduct a detailed review of this new system radar program report. The symposium lasted a full 4 days, and the experts at the meeting voted unanimously to adopt the report. Two well-known old experts attending the meeting said deeply: "We haven't seen such a detailed argumentation report for many years".

This is a pioneering offensive to fill a gap in the country and start from scratch. The next battle was even more arduous. After more than 800 days and nights of effort, thousands of experiments, and tens of thousands of test data acquisition, Liu Yongtan ’s pre-research project of the Ministry of Space, “Key Technologies and Scheme Demonstrations of New System Radar” was obtained. fruits, many breakthroughs in key technologies for the development of new radar system, China has successfully laid a good foundation.

In July 1986, the Ministry of Aerospace Industry held an appraisal meeting of key technical achievements of the new system radar at Harbin Institute of Technology. More than 50 experts carefully reviewed, discussed and commented, and agreed that "Harbin Institute of Technology has made significant progress in technical research in more than two years. It has mastered the main key technologies of the new system radar, and certain individual technologies have entered The international and domestic ranks first. As the main key technologies have been broken, the original plan has been proved to be feasible, and the conditions for further improving the radar system design and establishing experimental stations have been met. Application and basic research projects.

LD-JHC300 surface-wave over-the-horizon radarIIn 1986, Liu Yongtan began to preside over the "new system radar research" and worked hard to develop a complete radar system. In 1989, China's first new system radar station was completed. In April 1990, the radar station completed the commissioning of the whole machine. In October 1990, an appraisal meeting jointly held by multiple national departments announced: "The research results of the new system of radar have reached the international advanced level." In 1991, the project won the first prize of the National Science and Technology Progress Award.

n 1990, China established the first high-frequency ground-wave over-the-horizon test station in Weihai, and successfully tracked targets such as ships and aircraft beyond the horizon, and also conducted ship-based ground-wave radar test work on this basis. successfully detected ship hundreds of kilometers away, in order to apply domestic ground wave OTH radar has laid a solid foundation.

LD-JHC300 surface-wave over-the-horizon radarWeihai, formerly called Weihaiwei, is a city in eastern Shandong province, China. It is the easternmost prefecture-level city of the province and a major seaport. Weihai borders Yantai to the west and the Yellow Sea to the east. It is a beautiful coastal city and a historical and cultural city. Weihai possesses the reputation of "Lands of the Sea" and "Xanaduyuan" as Liu Chengdao, "the place where the sun rises and dances", and Shidao Chishan, known as the "Oriental God Mountain and Buddhist Sacred Place", which is completely true in Taoism The Bishan Mountain, which is an auspicious place, is famous for its sandy silver like snow and soft moss, and it is known as "the first beach in the world" and many other tourist attractions. Weihai is the birthplace of Beiyang Navy, the first navy of China in modern times, and the place where the Sino-Japanese War of 1895 was taking place. After the Sino-Japanese War of 1895, it was one of the "seven sons" who occupied and returned to the motherland. This facility is visible in current Google Earth imagery. The location does not look outward to potential threats such as Japan, but rather is inward looking, with the active shipping traffic of the Bohai Gulf providing a target-rich environment for testing and experimentation.

Although the research results have won the first prize of the National Science and Technology Progress Award, Liu Yongtan feels that this is not enough. He believes that if these results cannot be turned into real applications, it will undoubtedly be like a sword without an edge. In China, this is a huge waste and loss for the country. "We must turn the results in the laboratory into real applications." Facing yet another important decision in life, Liu Yongtan once again made a decision for the benefit of the little ones. This time, he knew it would take more than 8 years. What happened next made Liu Yongtan deeply "surprisingly". After learning about his decision, all the team members made a full support decision.

The new system radar project has received great attention from the state. It is of great significance to the country, schools and majors. We are under great pressure, but we must do a good job. "In 1997, the radar of the new system was officially approved, and Harbin Institute of Technology as the overall unit undertook the development work. This is the first time in a domestic university. Everyone knows that there is a road that can only go forward but not back. Xiang came from bitter cold. According to the requirements of the relevant state departments to continue to improve the radar performance, it is more than 10 years of hard work and hard work, and Liu Yongtan and his team have successfully completed the task again.

Liu Yongtan's new system of radar broke the monopoly of foreign technology and made China one of the few countries in the world with this technology. It has provided effective countermeasures against many threats that have long plagued radar and cost more than other technologies. Low, has a very broad application prospect. It is worth mentioning that this achievement, which won the first prize of the National Science and Technology Progress Award in 2015, will play an irreplaceable and powerful role in the defense of the motherland's seas and territories.

At the 2016 air show, China Aerospace Science and Industry Corporation not only launched the CM302 supersonic anti-ship missile, but also launched two supporting super-horizon radars, one is a microwave super-horizon radar and the other is based on the academician Liu Yongtan LD-JHC300 ground-wave over-the-horizon radar manufactured by research results.

According to reports, the LD-JHC300 ground-wave over-the-horizon radar uses the characteristics of vertically polarized high-frequency electromagnetic waves to be propagated along the coastal surface, breaks through the limitation of earth's curvature, and does not rely on meteorological conditions to achieve over-vision of targets such as ships on the sea Distance, continuous monitoring, and provide early warning information. It can be used for over-the-horizon and continuous surveillance of large and medium-sized moving targets on the sea surface, and provides protection for the national marine economic exclusive zone. The radar can also be networked with multiple units and fused with other coastal surveillance radars to form a unified sea surface situation monitoring system.

In summary, the high-frequency ground wave radar installed China's 18,000 km coastline with fire eyes that can detect aircraft, ships, and missiles, greatly enhancing China's air defense, antimissile, anti-stealth, anti-ship, and sea detection capabilities. The maintenance of China's security and interests can be guaranteed by reliable technology.



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Page last modified: 18-10-2021 15:46:52 ZULU