Dave Majumdar February 20, 2017
With a missile warhead large enough, the range resolution does not have to be precise. For example, the now antiquated S-75 Dvina—known in NATO parlance as the SA-2 Guideline—has a 440-pound warhead with a lethal radius of more than 100 feet. Thus, a notional twenty-microsecond compressed pulse with a range resolution of 150 feet should have the range resolution to get the warhead close enough—according to Pietrucha’s theory. The directional and elevation resolution would have to be similar with an angular resolution of roughly 0.3 degrees for a target at thirty nautical miles because the launching radar is the only system guiding the SA-2. For example, a missile equipped with its own sensor—perhaps an infrared sensor with a scan volume of a cubic kilometer—would be an even more dangerous foe against an F-22 or F-35.
The United States has poured ten of billions of dollars into developing fifth-generation stealth fighters such as the Lockheed Martin F-22 Raptor and F-35 Joint Strike Fighter. However, relatively simple signal processing enhancements, combined with a missile with a large warhead and its own terminal guidance system, could potentially allow low-frequency radars and such weapons systems to target and fire on the latest generation U.S. aircraft.
It is a well-known fact within Pentagon and industry circles that low-frequency radars operating in the VHF and UHF bands can detect and track low-observable aircraft. It has generally been held that such radars can’t guide a missile onto a target—i.e. generate a “weapons quality” track. But that is not exactly correct—there are ways to get around the problem according to some experts.
Traditionally, guiding weapons with low frequency radars has been limited by two factors. One factor is the width of the radar beam, while the second is the width of the radar pulse—but both limitations can be overcome with signal processing.
The width of the beam is directly related to the design of the antenna—which is necessarily large because of the low frequencies involved. Early low-frequency radars like the Soviet-built P-14 Tall King VHF-band radars was enormous in size and used a semi-parabolic shape to limit the width of the beam. Later radars like the P-18 Spoon Rest used a Yagi-Uda array—which were lighter and somewhat smaller. But these early low frequency radars had some serious limitations in determining the range and the precise direction of a contact. Furthermore, they could not determine altitude because the radar beams produced by these systems are several degrees wide in azimuth and tens of degrees wide in elevation.
Another traditional limitation of VHF and UHF-band radars is that their pulse width is long and they have a low pulse repetition frequency [PRF]—which means such systems are poor at accurately determining range. As Mike Pietrucha, a former Air Force an electronic warfare officer who flew on the McDonnell Douglas F-4G Wild Weasel and Boeing F-15E Strike Eagle once described to me, a pulse width of twenty microseconds yields a pulse that is roughly 19,600 ft long—range resolution is half the length of that pulse. That means that range can’t be determined accurately within 10,000 feet. Furthermore, two targets near one another can’t be distinguished as separate contacts.
Signal processing partially solved the range resolution problem as early as in the 1970s. The key is a process called frequency modulation on pulse, which is used to compress a radar pulse. The advantage of using pulse compression is that with a twenty-microsecond pulse, the range resolution is reduced to about 180 feet or so. There are also several other techniques that can be used to compress a radar pulse such as phase shift keying. Indeed, according to Pietrucha, the technology for pulse compression is decades old and was taught to Air Force electronic warfare officers during the 1980s. The computer processing power required for this is negligible by current standards, Pietrucha said.
Engineers solved the problem of directional or azimuth resolution by using phased array radar designs, which dispensed with the need for a parabolic array. Unlike older mechanically scanned arrays, phased array radars steer their radar beams electronically. Such radars can generate multiple beams and can shape those beams for width, sweep rate and other characteristics. The necessary computing power to accomplish that task was available in the late 1970s for what eventually became the Navy’s Aegis combat system found on the Ticonderoga-class cruisers and Arleigh Burke-class destroyers. An active electronically scanned array is better still, being even more precise.
With a missile warhead large enough, the range resolution does not have to be precise. For example, the now antiquated S-75 Dvina—known in NATO parlance as the SA-2 Guideline—has a 440-pound warhead with a lethal radius of more than 100 feet. Thus, a notional twenty-microsecond compressed pulse with a range resolution of 150 feet should have the range resolution to get the warhead close enough—according to Pietrucha’s theory.
The directional and elevation resolution would have to be similar with an angular resolution of roughly 0.3 degrees for a target at thirty nautical miles because the launching radar is the only system guiding the SA-2. For example, a missile equipped with its own sensor—perhaps an infrared sensor with a scan volume of a cubic kilometer—would be an even more dangerous foe against an F-22 or F-35.
Dave Majumdar is the defense editor for the National Interest. You can follow him on Twitter: @davemajumdar.
Source: National Interest “Stealth-Killer: How Russia or China Could Crush America’s F-35 or F-22 Raptor”
Note: This is National Interest’s article I post here for readers’ information. It does not mean that I agree or disagree with the article’s views.
According to National Interest’s article by Dave Majumdar on February 10, 2017, a report of the Center for Strategic and Budgetary Assessments (CSBA) commissioned by US Navy says that the US has to develop a new stealth manned fighter to contend for air superiority with China’s J-20.
The article says, “The F/A-18E/F Super Hornet and the Lockheed Martin F-35C Joint Strike Fighter—which are not dedicated air superiority fighters—would not be suitable to defeat advanced adversary air defenses or enemy aircraft such as the Chengdu J-20 or other Chinese fifth-generation warplanes. ‘In contrast to today’s multimission strike-fighters, such as the F-35C, the design of these aircraft would need to focus mostly on the fighter mission rather than strike, so that they would have the speed, endurance, maneuverability, and air-to-air sensor capability needed for counter-air operations,’ the report states.”
That is only natural because when the US began developing F-35, no other country has stealth fighter to contend for air supremacy with F-35, therefore there is much more emphasis on F-35’s capabilities in penetrating enemy air defense to attack enemy targets on land or at sea.
Now, China has developed J-20 specially for grabbing air supremacy from US stealth fighters. The US finds it in a poor position and is in dire need for some fighters to deal with J-20. Sad for US Navy. No worry, US Navy can ask Congress for lots of funds to develop new stealth fighters for air superiority.
The problem is that China is also spending a lot in developing fighter jets superior to US ones and so is Russia. The US has to conduct arms race in earnest with both Russia and China.
Usually, at least one of the two countries competing with the US may develop something better than US ones. If it is China, US will lose the arms race. However, if it is Russia, the US will also lose to China as Russia is willing to sell and China can afford the purchase of Russia’s best fighter jets as proved by its purchase of Russia’s so far the best fighter jet Su-35.
Comment by Chan Kai Yee on National Interest’s article, full text of which can be viewed at http://nationalinterest.org/blog/the-buzz/the-us-navy-needs-new-fighter-russia-china-are-blame-19409.
When the US wanted China to respect Hague arbitration ruling to give up China’s rights and interests in the South China Sea, Chinese troops conducted its largest drill there and Chinese navy chief pointed his finger at his US counterpart in his talks with him. Soon afterwards Chinese air force began to conduct combat patrol in the South China Sea especially on the disputed Scarborough Shale.
Now, Reuters says in its report “Trump nominee says China should be denied access to South China sea islands”, “U.S. President-elect Donald Trump’s nominee for secretary of state set a course for a potentially serious confrontation with Beijing on Wednesday, saying China should be denied access to islands it has built in the contested South China Sea.”
What does that mean?
It means the nominee Rex Tillerson wants a real war instead of trade war with China.
The US is preparing for that as it has been sending a squadron of F-35, its most advanced fighter jets, to Japan for the war.
China is not less prepared as it has been stepping up the development, production and deployment its most advanced fighter jet J-20s so that if the US hurts China’s core interests of its rights and interests in the South China Sea, China has to fight. The Chinese ruling party the CCP will become extremely unpopular if it is afraid to fight.
We hope it will be a limited war between the two powers as the US cannot send its army to invade China given China’s huge modern army and US experience of defeat in Korean War. China, on the other hand, is utterly unable to send its army to the US.
China is now able to win the naval war as China’s J-20 is superior to F-35 in a war of defense and China can sink US aircraft carriers with saturate attack of its large number of anti-ship ballistic and cruise missiles.
What will follow then? Attack China with nuclear weapons in retaliation? That will be the end of human race.
Do Trump and his nominee Rex Tillerson want that?
Let’s hope that Rex Tillerson’s hardline statement is but rhetoric.
Comment by Chan Kai Yee on Reuters’ report, full text of which is reblogged below:
Trump nominee says China should be denied access to South China sea islands
By David Brunnstrom and Matt Spetalnick | WASHINGTON January 11, 2017
U.S. President-elect Donald Trump’s nominee for secretary of state set a course for a potentially serious confrontation with Beijing on Wednesday, saying China should be denied access to islands it has built in the contested South China Sea.
In comments expected to enrage Beijing, Rex Tillerson told his confirmation hearing before the U.S. Senate Foreign Relations Committee that China’s building of islands and putting military assets on those islands was “akin to Russia’s taking Crimea” from Ukraine.
Asked whether he supported a more aggressive posture toward China, he said: “We’re going to have to send China a clear signal that, first, the island-building stops and, second, your access to those islands also is not going to be allowed.”
The former Exxon Mobil Corp (XOM.N) chairman and chief executive did not elaborate on what might be done to deny China access to the islands it has built up from South China Sea reefs, equipped with military-length airstrips and fortified with weapons.
Tillerson also said Washington needed to reaffirm its commitment to Taiwan, which Beijing regards as a renegade province, but stopped short of Trump’s questioning of Washington’s long-standing policy on the issue.
“I don’t know of any plans to alter the ‘one China’ position,” he said.
Tillerson said he considered China’s South China Sea activity “extremely worrisome” and that it would be a threat to the “entire global economy” if Beijing were able to dictate access to the waterway, which is of strategic military importance and a major trade route.
He blamed the current situation on what he termed an inadequate U.S. response. “The failure of a response has allowed them just to keep pushing the envelop on this,” Tillerson said.
“The way we’ve got to deal with this is we’ve got to show back up in the region with our traditional allies in Southeast Asia,” he said.
Democratic President Barack Obama’s administration conducted periodic air and naval patrols to assert the right of free navigation in the South China Sea. These have angered Beijing, but seeking to blockade China’s man-made islands would be a major step further and a step that Washington has never raised as an option.
Tillerson’s words also went beyond Trump’s own tough rhetoric on China.
Obama has sought to forge a united front in Southeast Asia against China’s pursuit of its territorial claims, but some allies and partners who are rival claimants have been reluctant to challenge Beijing.
Tillerson called China’s South China Sea island-building and declaration of an air defense zone in waters of the East China Sea it contests with Japan “illegal actions.”
“They’re taking territory or control, or declaring control of territories that are not rightfully China’s,” he said.
Tillerson also said the United States could not continue to accept “empty promises” China had made about putting pressure on North Korea over that country’s nuclear and missile programs.
He said his approach to dealing with North Korea – which recently declared it is close to carrying out its first test of an intercontinental ballistic missile – would be “a long-term plan” based on sanctions and their proper implementation.
Asked if Washington should consider imposing “secondary sanctions” on Chinese entities found to be violating existing sanctions on North Korea, Tillerson said: “If China is not going to comply with those U.N. sanctions, then it’s appropriate … for the United States to consider actions to compel them to comply.”
He accused China of failing to live up to global agreements on trade and intellectual property, echoing past remarks by Trump, who has threatened to impose high, retaliatory tariffs on China. But Tillerson also stressed the “deeply intertwined” nature of the world’s two biggest economies.
“We should not let disagreements over other issues exclude areas for productive partnership,” he said.
(Reporting by David Brunnstrom and Matt Spetalnick; Editing by Jonathan Oatis)
By: Valerie Insinna, January 10, 2017 (Photo Credit: US Marine Corps)
WASHINGTON — A Marine Corps F-35B squadron has transferred from the United States to Marine Corps Air Station Iwakuni in Japan, marking the first permanent international deployment of the joint strike fighter, the service announced Tuesday.
Marine Corps spokesman Capt Kurt Stahl told Defense News that 10 F-35Bs from Marine Fighter Attack Squadron 121 (VMFA-121) departed Marine Corps Air Station Yuma in Arizona on Monday, with the first jets slated to arrive in Japan on Wednesday. All 10 F-35s will arrive at Iwakuni by Thursday. Eventually, an additional six jets will be relocated from Yuma to Iwakuni, bringing the squadron up to a full 16 aircraft.
VMFA-121 is a part of the 3rd Marine Aircraft Wing.
“The transition of VMFA-121 from MCAS Yuma to MCAS Iwakuni marks a significant milestone in the F-35B program as the Marine Corps continues to lead the way in the advancement of stealth fighter attack aircraft,” the service said in a statement.
The Marine Corps’ short takeoff vertical landing version of the F-35 is the first variant of the aircraft to be permanently stationed outside of the United States. VMFA-121 became the US military’s first operational F-35 squadron in July 2015. Since then, the squadron “has continued to fly sorties and employ ordnance as part of their normal training cycle,” the Marine Corps said.
One such demonstration was Exercise Steel Knight in December 2015, a live-fire exercise that combined ground and air operations. The F-35B also took part in a proof-of-concept demo aboard amphibious assault ship America last October, where pilots tested the jet’s ability to operate in harsh at-sea conditions with a range of weapons.
The Air Force will become the next US service to internationally deploy the joint strike fighter, but is opting to locate its first squadron in Europe rather than in the Asia-Pacific. The F-35A will be permanently based at Royal Air Force Base Lakenheath in England as early as 2020.
Source: Defense News “First F-35B Squadron Moves to Japan”
Note: This is Defense News’ report I post here for readers’ information. It does not mean that I agree or disagree with the report’ views.
That is in fact not a conundrum as China has given crystal clear massages in the short flight show of J-20 stealth fighter jet, but it seems a real conundrum because few military experts, commentators and reporters seem to take and understand the messages.
Some of them seem to have received no messages at all. For example, Tobin Harshaw wrote an article for Bloomberg titled “China’s New Jets Are Impressive. But Are They for Real?” to show his failure to understand the message. Harshaw concludes his article with the following statement of frustration: “The J-20 flyby showed only how little we know about China’s drive to become a cutting-edge military.”
He certainly fails to receive one of the two clear messages: J-20 has no cutting edge compared with US F-22 outside the region it defends. The flight show tells those who have military knowledge that J-20 is satisfactorily stealth only in its front. It is not satisfactorily invisible to radar or infrared detector from the sides and rear.
F-22 however is stealth from any angle. It is designed to go deep into enemy territories to attack enemy targets including ground ones.
In designing F-22, US military wants it to be perfect, but China does not want its J-20 to be perfect. It only wants J-20 to achieve one vital strategic goal. That is why Chinese air force chief commander is very much satisfied with J-20 in spite of its various shortcomings.
US experts, commentators and reporters are used to assume that China is developing its military in order to contend with the US for world hegemony or in better wording for world leadership. The flight show proves precisely the contrary. China is satisfied with its new stealth fighter that is in quite a few respects inferior to US ones for world hegemony. The flight show proves that China has no intention to contend with the US for world leadership.
Chinese leaders are wise to refrain from the ambition to pursue world leadership. If they have such ambition, I will denounce them as stupid.
China’s economy is much smaller than the US. China still lags behind the US in many areas of science and technology. China simply lacks the ability to contend with the US. Moreover, what benefit may world leadership bring China? To be heavily in debts like the US and unpopular even in countries such as the Philippines the US protects?
Therefore, J-20 is utterly not designed as a penetrating strike jet. It only serves the strategic goal of grabbing air supremacy from F-22 in defending Chinese homeland. It is a weapon of defense while F-22 is a weapon of attack.
Kyle Mizokami seems to know better in its article “China Has Big Plans For Its Deadly New Stealth Fighter: But is the J-20 a threat to American air superiority?” published on Foreign Policy on November 4. He knows that as I point out, J-20 cannot be a penetrating strike jet due to its less-effective stealth from the sides and rear. However as he has the wrong idea that China wants to project its power outside its border or resolve border disputes by force, he fails to take the message that China has no intention to use J-20 outside the area J-20 protects.
Mr. Mizokami mentions China’s disputes with Japan in the East China Sea. However, he fails to see that the disputed Diaoyu (known as Senkaku in Japan) Islands are but worthless rocks. What China contends for are the rich fish and energy resources around the islands. Chinese fishermen are fishing there and China has been conducting oil and gas exploration there smoothly. Why shall China fight a war with expensive J-20s for some rocks?
Similar is the case with China’s disputes in the South China Sea. Different from the rocks in the East China Sea, the rocks there can be used to build large artificial islands for fishing, fish farming, tourism and oil and gas exploitation. China has incurred huge costs to build seven large artificial islands enough for such purposes and for defense of the area against US intervention.
In addition, China is not so greedy as to exploit those resources alone. It wants cooperation with other claimants in doing so. Now all other claimants including Vietnam are willing to cooperate, why shall China use its expensive J-20 to fight a war?
We see from the above that J-20 flight show clearly revealed that J-20 cannot be used as a penetrating strike jet for projecting China’s power abroad, but foreign military experts, commentators and reporters do not or simply will not accept the message as the message contradicts their assumption of China’s intention to project power abroad.
The second message is also very clear: With J-20, China has air superiority in the area near it to prevent US attack of Chinese homeland.
The flight show makes very clear J-20’s super maneuverability by showing its vertical climbup and sharp U-turn and looping. As J-20 is a later development, it has better radar, electronics, sensors, etc. than F-22; therefore, it is able to contend for air supremacy with F-22.
As for F-35, it is smaller; therefore, its radar and weapons are inferior to J-20’s. As F-35 is not designed for dogfight due to the design presumption it is to deal with non-stealth fighter, test has proved that it cannot win dogfight even against F-15. J-20 has much better dogfight capability as its designer knows well there will be dogfight between stealth fighters when their missiles fail to hit.
Due to the high speed and radar invisibility of stealth fighters, when a stealth fighter finds an enemy stealth fighter, it does not have much time for missile attack before their distance has been reduced to dogfight distance. With better heavier radar, J-20 can detect F-35 earlier and shoot down it with long-range air-to-air missile. If the long-range missile misses, it can fire a short-range one. If that missile also misses, it will be able to shoot down the F-35 in dogfight. F-35 is simply no rival to J-20.
The above analysis justifies Chinese air force commander’s satisfaction with J-20 as J-20 will be able to achieve strategic goal of air superiority to defend Chinese homeland.
China has the advantage of having specific strategic goal in developing J-20 so that it is able to ignore some unnecessary functions such as sidewise and rear stealth, group data link, etc. to reduce the cost and duration of research and development. That makes J-20 much cheaper and easier to make. We can expect that China will make a larger number of J-20s than US F-22s and F-35s to dominate the airspace near China.
That is the most important message to the US: With J-20, China is sure to win if the US attacks it.
Comparison between J-20 and F-22 disregarding their entirely different strategic goals does not make sense!
Article by Chan Kai Yee
In its Situation Report, Foreign Policy says that it was surprised by China’s announcement yesterday that its aircraft carrier is ready for combat. So was Washington Post in its report yesterday.
In fact, China has not directly made such an announcement. Foreign Policy says China has made such an announcement based on the report on Global Times’ interview with the carrier’s political commissar Li Dongyou, who said in the interview that the ship is “constantly prepared to fight against enemies.”
The US must be surprised because China previously described the Liaoning carrier as a platform for testing and training. US military experts predicted lots of China’s problems in producing carrier-based fighter jets, training pilots for the jets, etc. Even the arrest cable for landing of the fighter jets may be a serious headache.
That is why both Foreign Policy and Washington Post regard Li’s words as surprise announcement in their reports.
Surprise is natural as the US always underestimates China’s ability. However both media are wrong in predicting that the carrier will be used “to reinforce” (Washington Post’s wording) or in “underscoreing” (Foreign Policy’s wording) China’s claims in the South China Sea challenged by U.S. Navy and others.
The Liaoning deploys only 24 J-15s that will not be fully armed due to sky-jump takeoff. The three airports on China’s artificial islands in the South China Sea may accommodate at least 12 dozens of J-20 heavy stealth fighter jets there with much greater fire power. Moreover, China will soon deploy its J-10C stealth fighter jets with entirely new stealth technology completely different from US one.
J-10C instead of J-15 will be able to win dogfight against US F-22 due to its super maneuverability.
Dogfight capability is not necessary for a stealth fighter jet in dealing with a non-stealth one, but is indispensable for a stealth fighter jet in fighting another stealth fighter jet. As F-35 is not designed for fighting a stealth fighter and is a lighter warplane unable to carry better radar, it is utterly no rival to China’s J-20 and J-10C. Only F-22 may be able to contend with J-20 and J-10C, but without ground support near China, it has great disadvantage.
Since China has built three large unsinkable fixed aircraft carriers on its artificial islands in the South China Sea, it needs no aircraft carriers there, especially the Liaoning that is much inferior to US ones.
Comment by Chan Kai Yee on Foreign Policy and Washington Post’s reports, full text of which can be viewed respectively at https://mail.google.com/mail/#inbox/1586822dc8796243 and https://www.washingtonpost.com/world/asia_pacific/china-says-aircraft-carrier-now-ready-for-combat/2016/11/15/748addc8-aaf4-11e6-8f19-21a1c65d2043_story.html
PLA website says in its report this morning that J-20 has integrated the designs of various fighter jets including the shape of F-22’s nose, F-35’s electro-optical Distributed Aperture System, Russian T-50’s all-moving vertical stabilizer, etc. It is installed with active phased array radar and electronic warfare and electro-optical systems that very few countries in the world are able to make.
It is of excellent stealthy design and equipped with advanced navigation electronics and weapon systems strong enough to contend with any stealth fighter jets in the area around China.
It can be a stealth reconnaissance aircraft. Its powerful information system enables it to be the command fighter jet of a fleet of non-stealth fighter jets like an AEW&C aircraft. It can also lead a fleet of drones to fight in the style of a swarm of bees.
As J-20 is the first stealth fighter to be deployed in Chinese air force. Chinese military will study new tactics and combat methods to integrate it with other advanced air battle equipment and technology and explore through training the way to give play to the optimal combat capabilities of all the equipment and technology combined. Chinese military will gradually develop a theory of combat centered on J-20 that will make J-20 the scariest weapon to enemy from abroad.
Source: mil.huanqiu.com “PLA media: J-20 can contend with any fourth-generation fighter jet in the world, already world leader” (summary by Chan Kai Yee based on the report in Chinese)