STEALTH TECHNOLOGY

Rohan Bhavsar B120087505

Content• Introduction • History• Radar• Method used in stealth technology• India’s development in Stealth technology• Advantages• Disadvantages• Conclusion

What is Stealth Technology?• Scientifically know as LOW OBSERVABILITY TECHNOLOGY.

• In simple terms, it allows an aircraft to be partially invisible to radar or any other means of detection.

• This gives a clear and safe striking distance for the aircraft.

History

The idea of stealth comes from the concept of camouflage tactis used by soldiers in jungles for hiding purpose.

• One of the earliest aircraft was the horten ho 229 made by germans late in world war ii.

• It was come under consideration when cia requested funding for stealth aircrafts

• The theory comes into existence from the aircraft like f-117 night walker and b-2 spirit.

RADAR

• Radio Detection And Ranging.

• Radar is an object-detection system that uses radio waves to determine the range, altitude, direction, or speed of objects.

• Radar was developed for war application, now its applications had diversified.

Radar

antenna

transmits radio

waves

Encounter with enemy

Radio waves get reflected back

Measurement of the time for reflection

Calculation of the distance of the object

Metal body of an airplane is good at reflecting signals

Method Used in Stealth Technology• Camouflage Tactics

• Shape of aircraft

• Plasma stealth technology

• Radar absorbing material (RAM)

• Active cancellation system

CAMOUFLAGE TACTIS• It came by British in word war I.• It is a military science, the art and practice of concealment

and visual deception in war.• It means defeating enemy observations by concealing or

mislead.

Shape Of Stealth Aircraft

• The most effective way to counteract the ability of radar was to scatter the radar waves from the transmitter to direction where receives would be unlikely to be located.

• The ideal shapes to return radar would be dihedral or trihedral corners.

• The first aircraft which fully utilize this research is f-117

Conventional Aircraft• 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:

Stealth Aircraft• 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:

F-117 NIGHT WALKER USA

In this Plasma stealth the aircraft injects a stream of ionized gas which envelopes the aircraft due to which most of the radar wave are absorbed, this make the aircraft completely invisible.

Plasma Stealth

First develop by Russia

Radar absorbing material(ram)• Radiation-absorbent material, usually known as RAM, is

a material which has been specially designed and shaped to absorb incident RF radiation (also known as non-ionising radiation), as effectively as possible, from as many incident directions as possible. The more effective the RAM, the lower the resulting level of reflected RF radiation.

Radar absorbing material(ram)

• They are used to absorb the energy of the radar wave, so to prevent the reception of a reflected signal by the antenna.

• RAM is usually a dielectric material such as carbon or magnetic ferrite.

Types of radar-absorbent material (RAM)• Iron ball paint absorber

• One of the most commonly known types of RAM is iron ball paint.

• It contains tiny spheres coated with carbonyl iron or ferrite. 

• Radar waves induce molecular oscillations from the alternating magnetic field in this paint, which leads to conversion of the radar energy into heat

• The heat is then transferred to the aircraft and dissipated.

• The iron particles in the paint are obtained by decomposition of iron Penta carbonyl and may contain traces of carbon, oxygen, and nitrogen.

• Jaumann absorber• A Jaumann absorber or Jaumann layer is a radar-absorbent

substance

• Carbon nanotube• Radars work in the microwave frequency range, which can

be absorbed by MWNTs. Applying the MWNTs to the aircraft would cause the radar to be absorbed and therefore seem to have a smaller radar cross-section. One such application could be to paint the nanotubes onto the plane.

Active cancellation system• The main purpose is reducing the RCS while cancelling the

reflected radar signal by a process of modifying and retransmitting the incident radar waves, rather than having the radar jammed.

• The method is also called “active loading”.

• The active cancellation platform radiates counter signals, which have the same amplitude but reversed phase from the radar.

• Such that the reverse phase nullifies the incoming signal and thus makes the aircraft invisible to radar.

Active cancellation system

• The HAL Advanced Medium Combat Aircraft (AMCA) is an Indian programme of a fifth-generation fighter aircraft. It is being developed by an aerospace industry team which consists of the Aeronautical Development Agency as the design firm with manufacturing carried out by Hindustan Aeronautics Limited (HAL) as the primary contractor and main assembly firm. It is a single-seat,twin-engine, stealth supermaneuverable all weather multirole fighter aircraft.

India’s step towards Stealth Aircraft

Advantages1. A smaller number of stealth vehicles may replace fleet of conventional attacks vehicles with the same or increased combat efficiency. Possibly resulting in longer term savings in the military budget.  2. A Stealth vehicles strike capability may deter potential enemies from taking action and keep them in constant fear of strikes, since they can never know if the attack vehicles are already underway.  3. The production of a stealth combat vehicles design may force an opponent to pursue the same aim, possibly resulting in significant weakening of the economically inferior party.  4. Stationing stealth vehicles in a friendly country is a powerful diplomatic gesture as stealth vehicles incorporate high technology and military secrets. 5. Decreasing causality rates of the pilots and crew members.

Disadvantages1. 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.  2. The stealth aircraft can carry only reduced amount of payload. 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.  3. 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.

ConclusionStealth technology is clearly the future of air combat. In the future, as air defense systems grow more accurate and deadly, stealth technology can be a factor for a decisive by a country over the other. In the future, stealth technology will not only be incorporated in fighters and bombers but also in ships, helicopters, tanks and transport planes. Ever since the Wright brothers flew the first powered flight, the advancements in this particular field of technology have seen staggering heights. Stealth technology is just one of the advancements that we have seen. In due course of time we can see many improvements in the field of military aviation which would one-day even make stealth technology obsolete.