Sunday, October 13, 2013

Stealth or low observability (as it is scientifically known) is one of the most misunderstood and misinterpreted concepts in military aviation by the common man. Stealth aircraft are considered as invisible aircraft, which dominate the skies. With an additional boost from Hollywood action movies, stealth is today termed as the concept invincibility rather than invisibility. Though, the debate still continues on whether stealth technology can make an aircraft invincible it was found that stealth aircraft are detectable by radar.

The motive behind incorporating stealth technology in an aircraft is not just to avoid missiles being fired at is but also to give total deniability to covert operations. This is very much useful to strike targets where it is impossible to reach. Thus we can clearly say that the job of a stealth aircraft pilot is not to let others know that he was ever there.

How does Stealth technology work?

The concept behind the stealth technology is very simple. As a matter of fact it is totally the principle of reflection and absorption that makes aircraft "stealthy".
The goal of stealth technology is to make an airplane invisible to radar. There are two different ways to create invisibility:
  • ·       The airplane can be shaped so that any radar signals it reflects are reflected away from the radar equipment.
  • ·         The airplane can be covered in materials that absorb radar signals.

  • Most conventional aircraft have a rounded shape. This shape makes them aerodynamic, but it also creates a very efficient radar reflector. The round shape means that no matter where the radar signal hits the plane, some of the signal gets reflected back.
  • A stealth aircraft, on the other hand, is made up of completely flat surfaces and very sharp edges. When a radar signal hits a stealth plane, the signal reflects away at an angle, like this:

In addition, surfaces on a stealth aircraft can be treated so they absorb radar energy as well. The overall result is that a stealth aircraft like an F-117A can have the radar signature of a small bird rather than an airplane. The only exception is when the plane banks -- there will often be a moment when one of the panels of the plane will perfectly reflect a burst of radar energy back to the antenna.

What is Plasma Stealth? 
Plasma stealth technology is what can be called as "Active stealth technology" in scientific terms. This technology was first developed by the Russians. It is a milestone in the field of stealth technology. The technology behind this not at all new. The plasma thrust technology was used in the Soviet / Russian space program. Later the same engine was used to power the American Deep Space 1 probe.

In plasma stealth, the aircraft injects a stream of plasma in front of the aircraft. The plasma will cover the entire body of the fighter and will absorb most of the electromagnetic energy of the radar waves, thus making the aircraft difficult to detect. The same method is used in Magneto Hydro Dynamics. Using Magneto Hydro Dynamics, an aircraft can propel itself to great speeds

Disadvantages of stealth technology 

  • Stealth technology has its own disadvantages like other technologies. Stealth aircraft cannot fly as fast or is not maneuverable like conventional aircraft. The F-22 and the aircraft of its category proved this wrong up to an extent. Though the F-22 may be fast or maneuverable or fast, it can't go beyond Mach 2 and cannot make turns like that.
  • Another serious disadvantage with the stealth aircraft is the reduced amount of payload it can carry. As most of the payload is carried internally in a stealth aircraft to reduce the radar signature, weapons can only occupy a less amount of space internally. On the other hand a conventional aircraft can carry much more payload than any stealth aircraft of its class.
  • Whatever may be the disadvantage a stealth aircraft can have, the biggest of all disadvantages that it faces is its sheer cost. Stealth aircraft literally costs its weight in gold
  • Fighters in service and in development for the USAF like the B-2 ($2 billion), F-117 ($70 million) and the F-22 ($100 million) are the costliest planes in the world.

The Future

  • In the never ending rivalry between offence and defence, there will be a continuing race in development between stealth technology and detection devices of air defence systems. 
  • In future, stealth technology will be extended to transport aircraft, rotary wing and unmanned serial platforms. 
  • While stealth technology will undoubtedly play an increasingly critical role in air operations in the future, radar systems of the future will also have far greater capability to defeat stealth. 
  • The future holds even greater challenges for human ingenuity and the capability to innovate.

  • Anti- stealth technology is based on the aim that a stealthy craft remain invisible to detecting radar and infrared sensors and that too especially at long ranges.
  • These technologies can be entirely nullified as well, with the help of the detecting radar and/or infrared sensors searching. This works for searching the background behind the stealthy craft but not for the stealthy craft.
  • After the detection the stealthy craft shows up in the form of a black or blank outlined figure in front of the background. 
  • This is very similar to the way the location of the moon can be pinpointed with extreme accuracy and the movement can be tracked with great precision during a solar eclipse, even when the moon cannot be observed itself in an eclipse.
  • Basically the stealthy crafts use materials which absorb the radar waves or use pointed and flat designs to reflect the waves in different directions, away from the radar equipment.
  • In respect of infrared the basic principle used is by minimizing the heat from the engines and other heat emitting spots thereby achieving the objective of stealth technology. 
  • This technology can be nullified entirely by the detecting radar and/or infrared sensors, which would search the background of the stealthy craft and not the craft itself.

There are three Methods used till date for the anti-stealth technology: 

1.Airborne Method
2.Satellite based Method
3.Surface based Method.


Stealth Technology and India 

INS Sahyadri
Stealth frigate.Project 17= Indian navy is building stealth frigates under this project.

Teg, Tarkash, Trikand
These are also stealth frigates. India bought these from Russia.These will be used for anti-piracy operations.

  • The Sukhoi/HAL FGFA, the Indian version of the PAK FA is scheduled to be introduced from 2017 in higher numbers, also to perform various missions.

IUSAV project 

  • India has been developing its own unmanned stealth bomber, officially designated as Indian Unmanned Strike Air Vehicle (IUSAV).
  • Development of IUSAV would give India an entry to the exclusive club of countries engaged in building unmanned stealth bomber aircraft, which are intelligent, autonomous and built to kill.
  • Though the government has acknowledged its IUSAV project, it has been silent about its details as it is not only ambitious but also more controversial than anything that India has ever attempted before for national defence.

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