Very low detectability, informally known as stealth technology** or also invisibility, covers various cloaking techniques, most used on planes and ships, to make them less visible to radar.[1] This technology became notorious in wars such as the Gulf War in 1991.
Invisibility technologies are not new. Special operations infantry commandos have always used it, even airplanes making use of their maneuverability, following the profile of the terrain or using electronic countermeasures.[2] But invisibility technologies refer more to the design and composition of the vehicle to drastically reduce the radar echo they reflect.[3].
A mission carried out by a vehicle using stealth technologies will be discovered (for example) when the target is destroyed. Attacking using surprise, doing so at high speed, and maximizing the use of stealth technologies increases the effectiveness of the attack, making the enemy less likely to defend against that and future attacks. On the contrary, the design concessions involved in making a completely stealthy weapon mean that it has almost no chance of escape if detected.
History
Camouflage to aid or avoid predation predates humanity, and hunters have been using vegetation to conceal themselves for perhaps as long as people have taken up hunting. The first application of camouflage in war is impossible to determine. Methods for visual concealment in warfare were documented by Sun Tzu in the book The Art of War in the century BC. C., and by Frontinus in the work Strategemata") in the century AD.[4].
In England, irregular century ranger units were the first to adopt drab colors (common in Irish century units) as a form of camouflage, following examples from the European continent.
During World War I, the Germans experimented with the use of "Cellon" (cellulose acetate), a transparent covering material, in an attempt to reduce the visibility of military aircraft. Individual examples of the Fokker E.III fighter monoplane Eindecker, the two-seat observation biplane Albatros C.I, and the Linke-Hofmann heavy bomber prototype R.I") were covered with Cellon. However, sunlight shining on the material made the aircraft even more visible. "Cellon" was also found to degrade rapidly from both sunlight and temperature changes during flight, making it that the effort to make transparent airplanes ceased.[5].
invisible design
Introduction
Very low detectability, informally known as stealth technology** or also invisibility, covers various cloaking techniques, most used on planes and ships, to make them less visible to radar.[1] This technology became notorious in wars such as the Gulf War in 1991.
Invisibility technologies are not new. Special operations infantry commandos have always used it, even airplanes making use of their maneuverability, following the profile of the terrain or using electronic countermeasures.[2] But invisibility technologies refer more to the design and composition of the vehicle to drastically reduce the radar echo they reflect.[3].
A mission carried out by a vehicle using stealth technologies will be discovered (for example) when the target is destroyed. Attacking using surprise, doing so at high speed, and maximizing the use of stealth technologies increases the effectiveness of the attack, making the enemy less likely to defend against that and future attacks. On the contrary, the design concessions involved in making a completely stealthy weapon mean that it has almost no chance of escape if detected.
History
Camouflage to aid or avoid predation predates humanity, and hunters have been using vegetation to conceal themselves for perhaps as long as people have taken up hunting. The first application of camouflage in war is impossible to determine. Methods for visual concealment in warfare were documented by Sun Tzu in the book The Art of War in the century BC. C., and by Frontinus in the work Strategemata") in the century AD.[4].
In England, irregular century ranger units were the first to adopt drab colors (common in Irish century units) as a form of camouflage, following examples from the European continent.
During World War I, the Germans experimented with the use of "Cellon" (cellulose acetate), a transparent covering material, in an attempt to reduce the visibility of military aircraft. Individual examples of the Fokker E.III fighter monoplane Eindecker, the two-seat observation biplane Albatros C.I, and the Linke-Hofmann heavy bomber prototype R.I") were covered with . However, sunlight shining on the material made the aircraft even more visible. "Cellon" was also found to degrade rapidly from both sunlight and temperature changes during flight, making it that the effort to make transparent airplanes ceased.[5].
In 1916, the British modified a small SS-class airship for night reconnaissance over German lines on the Western Front. Equipped with a silenced engine and a black gas bag, the ship was both invisible and inaudible from the ground, but several night flights over German-held territory provided little useful knowledge and the idea was abandoned.
Diffuse illumination camouflage, a shipborne form of counterlight camouflage, was tested by the Royal Canadian Navy from 1941 to 1943. The Americans and British followed the concept for their aircraft: in 1945, a Grumman Avenger with Yehudi lights reached 2,700 m from a ship before being sighted. This ability was made obsolete by radar.[7]
The Chaff was invented in Britain and Germany at the beginning of World War II as a means of hiding aircraft from radar. In effect, the radar decoy acted on radio waves as much as a "smoke screen" acted on visible light.[8].
The submarine U-480") may have been the first stealth submarine. It featured an anechoic rubber lining plate, one of which contained circular air pockets to prevent ASDIC sonar.[9] Radar-absorbing paints and rubber-semiconductor composite materials (code names: Sumpf, Schornsteinfeger) were used by the Kriegsmarine on submarines in World War II. Tests showed that they were effective at reduce radar signals at both short (centimeters) and long (1.5 meters) wavelengths.[10].
In 1956, the CIA began attempting to reduce the radar cross section (RCS) of the U-2 spy plane. Three systems were developed: Trapeze, a series of wires and ferrite beads around the planform of the aircraft, a covering material with embedded PCB circuitry, and radar-absorbing paint. These were deployed in the field on so-called "dirty birds", but the results were disappointing, the increases in weight and drag not justifying any reduction in rates. [11]
In 1958, the US Central Intelligence Agency requested funding for a reconnaissance aircraft to replace the existing U-2 spy planes,[12] and Lockheed secured the contractual rights to produce it.[13] "Kelly" Johnson and his team at Lockheed's Skunk Works were tasked with producing the A-12 (or OXCART), which operated at high altitudes of 70,000 to 80 000 feet and a speed of Mach 3.2 to avoid radar detection. Various aircraft shapes were developed to reduce radar detection on earlier prototypes, designated A-1 to A-11. The A-12 included a number of stealth features with special fuel to reduce the exhaust plume signature, inclined vertical stabilizers, the use of composite materials in key locations, and overall finishing in radar-absorbing paint.[11].
In 1960, the USAF reduced the radar cross section of a Ryan Q-2C Firebee. This was achieved through specially designed screens over the air intake, radiation-absorbing material in the fuselage, and radar-absorbing paint.[14]
The United States Army issued a specification in 1968 that required an observation aircraft that would be acoustically undetectable from the ground when flying at an altitude of 1,500 feet (457 m) at night. This resulted in the Lockheed YO-3A Quiet Star"), which operated in South Vietnam from late June 1970 to September 1971.[15]
During the 1970s, the US Department of Defense launched the Lockheed Have Blue project with the goal of developing a stealth fighter. There was fierce bidding between Lockheed and Northrop to secure the multimillion-dollar contract. Lockheed incorporated into its offer a text written by the Russian-Soviet physicist Pyotr Ufimtsev") from 1962, entitled Method of Edge Waves in the Physical Theory of Diffraction, Soviet Radio, Moscow, 1962. In 1971 this book was translated into English with the same title by the Foreign Technology Division of the US Air Force.[16] The theory played a fundamental role in the design of the aircraft. American F-117 and B-2 stealth aircraft.[17][18][19] The equations described in the paper quantified how the shape of an aircraft would affect its radar detectability, called a radar cross section (RCS).[20] At the time, the Soviet Union did not have the supercomputer capability to solve these equations for real designs. This was applied by Lockheed in computer simulation to design a novel shape they called "Hopeless." Diamond", a play on Hope Diamond"), securing the contractual rights to produce the F-117 Nighthawk beginning in 1975. In 1977, Lockheed produced two 60% scale models under the Have Blue contract. The Have Blue program was a stealth technology demonstrator that lasted from 1976 to 1979. Northrop Grumman Tacit Blue also played a role in the development of composite material and curvilinear surfaces, low observability, fly-by-wire, and other stealth technology innovations. Have Blue's success led the Air Force to create the Senior Trend program that developed the F-117.[21][22].
Beginning
Stealth technologies are a combination of several techniques, especially:.
Tactics
Stealth aircraft such as the F-117 are generally used against highly fortified and defended ground targets such as command and control centers or anti-aircraft missile batteries. The radars cover the entire airspace surrounding these areas, even overlapping, making it impossible for a non-stealthy aircraft to enter that area. Stealth planes can be detected, but only if they pass very close to radars, so even for these planes there are risks. However, a stealth aircraft flying at a suitable altitude and according to a prepared flight plan can safely attack radar stations. Once these stations have been destroyed, conventional aircraft can begin to operate over the area.
Today, however, the concept of "strict stealth" that led to the construction of the F-117 and B-2 is considered obsolete due to advances in remote sensing systems and digital signal analysis.
The first fighter "Fighter (aircraft)") with a high level of stealth is the F-22 Raptor complemented by the F-35 JSF. However, aerial combat implies certain differences. A stealth aircraft can approach an aerial target with a greater chance of remaining undetected, allowing it to gain a better position for its guided weapons. Certain types of weapons are susceptible to being avoided by this type of aircraft. With high technology (common in modern fighters) complemented by active electronic scanners (AESA) stealth aircraft can act as AWACS control centers for other aircraft. Stealth aircraft are also a good escort for ground attack aircraft.
References
[1] ↑ Electromagnetic stealth technology: A review of wave-absorbing structures, Materials & Design
[2] ↑ Rao, G.A.; Mahulikar, S.P. (2002). «Integrated review of stealth technology and its role in airpower». Aeronautical Journal 106 (1066): 629-641.
[3] ↑ Mahulikar, S.P.; Sonawane, H.R.; Rao, G.A. (2007). «Infrared signature studies of aerospace vehicles». Progress in Aerospace Sciences 43 (7–8): 218-245. Bibcode:2007PrAeS..43..218M. doi:10.1016/j.paerosci.2007.06.002.: http://dspace.library.iitb.ac.in/xmlui/handle/10054/613
[4] ↑ Wey, Adam Leong Kok (15 de marzo de 2014). «Principles of Special Operations: Learning from Sun Tzu and Frontinus». Comparative Strategy 33 (2): 131-144. ISSN 0149-5933. S2CID 154557121. doi:10.1080/01495933.2014.897119.: https://es.wikipedia.org//portal.issn.org/resource/issn/0149-5933
[5] ↑ Haddow, G.W.; Grosz, Peter M. (1988). The German Giants – The German R-Planes 1914–1918 (3rd edición). London: Putnam. ISBN 0-85177-812-7.
[6] ↑ Abbott, Patrick (1989). The British Airship at War, 1914–1918. Terence Dalton. pp. 31-33. ISBN 0861380738.
[10] ↑ Hepcke, Gerhard (2007). The Radar War, 1930–1945. English translation by Hannah Liebmann. Radar World. p. 45. Consultado el 19 de septiembre de 2012.: http://www.radarworld.org/radarwar.pdf
[11] ↑ a b Pedlow, Gregory W.; Welzenbach, Donald E. (1992), The Central Intelligence Agency and Overhead Reconnaissance: The U-2 and OXCART Programs, 1954–1974, Washington, DC: Central Intelligence Agency .
[13] ↑ Richelson, J.T. (10 de septiembre de 2001). «Science, Technology and the CIA». The National Security Archive. The George Washington University. Consultado el 6 de octubre de 2009.: http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB54/
[16] ↑ National Air Intelligence Center, Wright-Patterson AFB, OH, 1971. Technical Report AD 733203, Defense Technical Information Center of USA, Cameron Station, Alexandria, VA, 22304-6145, USA.
[17] ↑ Browne, M.W. "Two rival designers led the way to stealthy warplanes", The New York Times, Sci. Times Sec., 14 May 1991.
[18] ↑ Browne, M.W. "Lockheed credits Soviet theory in design of F-117", Aviation Week Space Technology p. 27, December 1991.
[19] ↑ Rich, Ben and L. Janos, Skunk Works, Little Brown, Boston, 1994.
[21] ↑ Kevin (14 de julio de 2003). «F-117A Senior Trend». F-117A: The Black Jet. Consultado el 2 de septiembre de 2019.: http://www.f-117a.com/Senior.html
In 1916, the British modified a small SS-class airship for night reconnaissance over German lines on the Western Front. Equipped with a silenced engine and a black gas bag, the ship was both invisible and inaudible from the ground, but several night flights over German-held territory provided little useful knowledge and the idea was abandoned.
Diffuse illumination camouflage, a shipborne form of counterlight camouflage, was tested by the Royal Canadian Navy from 1941 to 1943. The Americans and British followed the concept for their aircraft: in 1945, a Grumman Avenger with Yehudi lights reached 2,700 m from a ship before being sighted. This ability was made obsolete by radar.[7]
The Chaff was invented in Britain and Germany at the beginning of World War II as a means of hiding aircraft from radar. In effect, the radar decoy acted on radio waves as much as a "smoke screen" acted on visible light.[8].
The submarine U-480") may have been the first stealth submarine. It featured an anechoic rubber lining plate, one of which contained circular air pockets to prevent ASDIC sonar.[9] Radar-absorbing paints and rubber-semiconductor composite materials (code names: Sumpf, Schornsteinfeger) were used by the Kriegsmarine on submarines in World War II. Tests showed that they were effective at reduce radar signals at both short (centimeters) and long (1.5 meters) wavelengths.[10].
In 1956, the CIA began attempting to reduce the radar cross section (RCS) of the U-2 spy plane. Three systems were developed: Trapeze, a series of wires and ferrite beads around the planform of the aircraft, a covering material with embedded PCB circuitry, and radar-absorbing paint. These were deployed in the field on so-called "dirty birds", but the results were disappointing, the increases in weight and drag not justifying any reduction in rates. [11]
In 1958, the US Central Intelligence Agency requested funding for a reconnaissance aircraft to replace the existing U-2 spy planes,[12] and Lockheed secured the contractual rights to produce it.[13] "Kelly" Johnson and his team at Lockheed's Skunk Works were tasked with producing the A-12 (or OXCART), which operated at high altitudes of 70,000 to 80 000 feet and a speed of Mach 3.2 to avoid radar detection. Various aircraft shapes were developed to reduce radar detection on earlier prototypes, designated A-1 to A-11. The A-12 included a number of stealth features with special fuel to reduce the exhaust plume signature, inclined vertical stabilizers, the use of composite materials in key locations, and overall finishing in radar-absorbing paint.[11].
In 1960, the USAF reduced the radar cross section of a Ryan Q-2C Firebee. This was achieved through specially designed screens over the air intake, radiation-absorbing material in the fuselage, and radar-absorbing paint.[14]
The United States Army issued a specification in 1968 that required an observation aircraft that would be acoustically undetectable from the ground when flying at an altitude of 1,500 feet (457 m) at night. This resulted in the Lockheed YO-3A Quiet Star"), which operated in South Vietnam from late June 1970 to September 1971.[15]
During the 1970s, the US Department of Defense launched the Lockheed Have Blue project with the goal of developing a stealth fighter. There was fierce bidding between Lockheed and Northrop to secure the multimillion-dollar contract. Lockheed incorporated into its offer a text written by the Russian-Soviet physicist Pyotr Ufimtsev") from 1962, entitled Method of Edge Waves in the Physical Theory of Diffraction, Soviet Radio, Moscow, 1962. In 1971 this book was translated into English with the same title by the Foreign Technology Division of the US Air Force.[16] The theory played a fundamental role in the design of the aircraft. American F-117 and B-2 stealth aircraft.[17][18][19] The equations described in the paper quantified how the shape of an aircraft would affect its radar detectability, called a radar cross section (RCS).[20] At the time, the Soviet Union did not have the supercomputer capability to solve these equations for real designs. This was applied by Lockheed in computer simulation to design a novel shape they called "Hopeless." Diamond", a play on Hope Diamond"), securing the contractual rights to produce the F-117 Nighthawk beginning in 1975. In 1977, Lockheed produced two 60% scale models under the Have Blue contract. The Have Blue program was a stealth technology demonstrator that lasted from 1976 to 1979. Northrop Grumman Tacit Blue also played a role in the development of composite material and curvilinear surfaces, low observability, fly-by-wire, and other stealth technology innovations. Have Blue's success led the Air Force to create the Senior Trend program that developed the F-117.[21][22].
Beginning
Stealth technologies are a combination of several techniques, especially:.
Tactics
Stealth aircraft such as the F-117 are generally used against highly fortified and defended ground targets such as command and control centers or anti-aircraft missile batteries. The radars cover the entire airspace surrounding these areas, even overlapping, making it impossible for a non-stealthy aircraft to enter that area. Stealth planes can be detected, but only if they pass very close to radars, so even for these planes there are risks. However, a stealth aircraft flying at a suitable altitude and according to a prepared flight plan can safely attack radar stations. Once these stations have been destroyed, conventional aircraft can begin to operate over the area.
Today, however, the concept of "strict stealth" that led to the construction of the F-117 and B-2 is considered obsolete due to advances in remote sensing systems and digital signal analysis.
The first fighter "Fighter (aircraft)") with a high level of stealth is the F-22 Raptor complemented by the F-35 JSF. However, aerial combat implies certain differences. A stealth aircraft can approach an aerial target with a greater chance of remaining undetected, allowing it to gain a better position for its guided weapons. Certain types of weapons are susceptible to being avoided by this type of aircraft. With high technology (common in modern fighters) complemented by active electronic scanners (AESA) stealth aircraft can act as AWACS control centers for other aircraft. Stealth aircraft are also a good escort for ground attack aircraft.
References
[1] ↑ Electromagnetic stealth technology: A review of wave-absorbing structures, Materials & Design
[2] ↑ Rao, G.A.; Mahulikar, S.P. (2002). «Integrated review of stealth technology and its role in airpower». Aeronautical Journal 106 (1066): 629-641.
[3] ↑ Mahulikar, S.P.; Sonawane, H.R.; Rao, G.A. (2007). «Infrared signature studies of aerospace vehicles». Progress in Aerospace Sciences 43 (7–8): 218-245. Bibcode:2007PrAeS..43..218M. doi:10.1016/j.paerosci.2007.06.002.: http://dspace.library.iitb.ac.in/xmlui/handle/10054/613
[4] ↑ Wey, Adam Leong Kok (15 de marzo de 2014). «Principles of Special Operations: Learning from Sun Tzu and Frontinus». Comparative Strategy 33 (2): 131-144. ISSN 0149-5933. S2CID 154557121. doi:10.1080/01495933.2014.897119.: https://es.wikipedia.org//portal.issn.org/resource/issn/0149-5933
[5] ↑ Haddow, G.W.; Grosz, Peter M. (1988). The German Giants – The German R-Planes 1914–1918 (3rd edición). London: Putnam. ISBN 0-85177-812-7.
[6] ↑ Abbott, Patrick (1989). The British Airship at War, 1914–1918. Terence Dalton. pp. 31-33. ISBN 0861380738.
[10] ↑ Hepcke, Gerhard (2007). The Radar War, 1930–1945. English translation by Hannah Liebmann. Radar World. p. 45. Consultado el 19 de septiembre de 2012.: http://www.radarworld.org/radarwar.pdf
[11] ↑ a b Pedlow, Gregory W.; Welzenbach, Donald E. (1992), The Central Intelligence Agency and Overhead Reconnaissance: The U-2 and OXCART Programs, 1954–1974, Washington, DC: Central Intelligence Agency .
[13] ↑ Richelson, J.T. (10 de septiembre de 2001). «Science, Technology and the CIA». The National Security Archive. The George Washington University. Consultado el 6 de octubre de 2009.: http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB54/
[16] ↑ National Air Intelligence Center, Wright-Patterson AFB, OH, 1971. Technical Report AD 733203, Defense Technical Information Center of USA, Cameron Station, Alexandria, VA, 22304-6145, USA.
[17] ↑ Browne, M.W. "Two rival designers led the way to stealthy warplanes", The New York Times, Sci. Times Sec., 14 May 1991.
[18] ↑ Browne, M.W. "Lockheed credits Soviet theory in design of F-117", Aviation Week Space Technology p. 27, December 1991.
[19] ↑ Rich, Ben and L. Janos, Skunk Works, Little Brown, Boston, 1994.
[21] ↑ Kevin (14 de julio de 2003). «F-117A Senior Trend». F-117A: The Black Jet. Consultado el 2 de septiembre de 2019.: http://www.f-117a.com/Senior.html