stealth technology

STEALTH TECHNOLOGY

Presented by:

ROHITH CHIMMANI

13311A04B3 ECE-C

Outline Introduction History Radar & Its Working Types of Detection Radar Cross Section (RCS) Advantages & Disadvantages Conclusion

Introduction

What’s stealth technology?• A technique of making objects invisible

• An important technology used in military operations

• Also known as LOT (Low Observable Technology)

• Task of Stealth Technology

HISTORY World War II played in important role in stealth technology development. Germans were the 1st developers Germans developed the stealth Nano-Paint during the WW-II

What is a Radar system?

Radar system is a system that help pilot in navigating while fly in space

It uses a continuous wave and frequency to keep in touch with

By radar system we could know how far the object is and its velocity

How it works? Radar system based on the techniques of

Echo and Doppler Shift using Radio waves.

The echo of a sound can be used to determine how far away something is.

The Doppler shift of the echo can determine how fast something is going.

There are sender and receiver that have been installed on ground and aircraft as well

How Stealth Technology avoid Radar detection ?

Two Major factors

Aircraft design Materials been used

Types of Detection Different radar signatures of vehicles can be catergorized as following:

Radar Cross Section (RCS) Infrared Signature Acoustic Signature Visible Signature

Radar Cross Section

Radar mainly work on electromagnetic wave reflection.

In order to avoid these reflection towards the radar receiver, we have to reduce the radar cross section of object.

Radar cross section (RCS) defines the ability of a vehicle to reflect a radar signal.

RCS Reduction Technique(Reduction in Radar Detection) Purpose shaping : The shape of the target’s reflecting surfaces is designed such that they

reflect energy away from the source.

Radar absorbent material : As an addition to highly reflective surfaces.

Active Cancellation : Target generates a radar signal equal in intensity but opposite in phase

to the predicted reflection of an incident radar signal

Vehicle shape

It should be coated with Radar Absorbing Materials Which deflect , absorbed incoming radar waves and reduce the

detection range.

Figure: Radar absorbing materials

Vehicle shape It should be coated with Radar Absorbing Materials Its tail should be kept Acute angle Planes wings has to kept at acute Design of the Nose

Shaping Normal design Curved design

F117 A NIGHTHAWK

Active Cancellation In this method we have some RF

source on object (plane, ship) which modify radar signal but in opposite phase that generate destructive interference.

Thus by the use of these three methods we can reduce RCS of our plane and can make them low observable.

Infra-red stealth Method to decrease the IR signature of the engines is to use

exhaust masking.

Hot zones such as engine exhaust , wing surface [friction due to air] get heated which rather increases the visibility

This is accomplished by placing the engines on top of the body and the wings, by which exhausts cannot be seen from below.

These part should be kept cool as possible it can be ,

Option would be mixing of cool air with the hot engine exhaust

Infra-red Stealth

Visual Stealth Low visibility is desirable for all military

applications

Earlier stealth aircraft were painted black and thus could be used during nights

Now days an electro chromic polymer is being developed for daytime stealth

These polymer sheets sense nature of the surrounding and change there color accordingly

Visible Stealth Stealth Nano - Carbon Paint

“Blackest “ known material of the world Absorb 99% of the received signal Excellent Electrical Conductivity and High Strength

Plasma will cover the whole body of the aircraft Plasma cloud will observe the Radar waves and prevent aircraft

detection

Plasma Stealth

Advantages

Few number of stealth aircrafts = Huge number of conventional aircrafts [Economical in long term]

Advantages

Few number of stealth aircrafts = Huge number of conventional aircrafts [Economical in long term]

Keeping the enemy in fear of aircraft’s existence. So they will remain in defence mood

The natural competition of war will result in economically weakening of the enemy.

Diplomatic result: Stealth aircrafts have high military technology and military secrets

Disadvantages Low speed and Maneuverability. Low amount of carried payload

Disadvantages Low speed and Maneuverability. Low amount of carried payload High cost:

B-2 bomber: $2 billion F-117A: $70 million F-22: $100 million

Wing shape => Unstable flight, Not enough uplift force for takeoff, Needing of complex computerized system for stable flight.

Conclusion Stealth Technology is the future of military combat technology.

In near future stealth technology can be used in other facilities like ships, helicopters, vehicles, etc.

The main problem of this technology is its high cost.

Stealth technology due to its high cost, cannot be a proper choice for developing countries.

New developments in other fields of technology such as Nanotechnology can be used instead of stealth technology due to their low cost.

References

http://en.wikipedia.org/wiki/Stealth_technology http://en.wikipedia.org/wiki/Radar http://en.wikipedia.org/wiki/Stealth_ship http://science.howstuffworks.com/question69.htm http://www.hyperstealth.com/Quantum-Stealth

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