This document is a technical seminar paper on stealth technology and stealth fighters presented by Vinay V Vali to fulfill the requirements for a Bachelor of Engineering degree. It discusses how radar works and is used by air traffic control, police, and military. It explains echo and Doppler shift and how they are combined in radar and sonar. It then covers the history of stealth technology, how stealth aircraft differ from conventional aircraft through radar absorbent surfaces and materials. Advantages like reduced casualties and costs are discussed along with high investment costs as a disadvantage. The future potential uses of stealth tech in other vehicles is presented before concluding stealth will be important but costly technology.

1. VISVESVARAYA TECHNOLOGICAL UNIVERSITY
Jnana Sangama, Belagavi – 590 018, Karnataka
A TECHNICAL SEMINAR ON
SSTTEEAALLTTHH TTEECCHHNNOOLLOOGGYY AANNDD SSTTEEAALLTTHH
FFIIGGHHTTEERR
Submitted in partial fulfillment of the requirements for the award of the degree of
BACHELOR OF ENGINEERING
IN
INDUSTRIAL & PRODUCTION ENGINEERING
By
VINAY V VALI
VIII Semester B. E. (I & PE)
USN: 4UB13IP044
DEPARTMENT OF STUDIES IN
INDUSTRIAL & PRODUCTION ENGINEERING
UNIVERSITY B. D. T COLLEGE OF ENGINEERING, DAVANGERE - 577 004
(A Constituent College of VTU, Belagavi)
2016-17
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2. CONTENTS:
 Introduction
 Who uses RADAR?
 Echo and Doppler shift
 History of Stealth technology
 Stealth technology
 RAS: Radar Absorbent Surfaces
 RAM: Radar Absorbent material
 Advantages and Disadvantages
 Future of Stealth technology
 Conclusion
 References 2

3. INTRODUCTION:
 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.
 The motive behind incorporating stealth technology is to make
an aircraft invisible for RAdio Detection And
Ranging(RADAR).
 Thus we can clearly say that the job of a stealth aircraft pilot is
not to let others know that he was ever there.
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4. Who uses RADAR Systems?
RADAR is used everyday by:
Air Traffic Control
Police
Military
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5. Echo:
 Echo occurs because some
of the sound waves in our
shout reflect off of a surface
(either the water at the
bottom of the well or the
canyon wall on the far side)
and travel back to our ears.
 The time taken between the
moment we shout and the
moment we hear the echo is
determined. By this we can
calculate the depth of well.
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6. Doppler Shift:
 Apparent change in the frequency of sound wave,
whenever there is a relative motion between the
source of sound and the observer.
 Named after the scientist Christian Doppler, who first
observed it.
 Let's say there is a car coming towards us at 60 miles
per hour (mph) and its horn is blaring. We will hear
the horn playing one "note" as the car approaches, but
when the car passes us, the sound of the horn will
suddenly shift to a lower note. It is the same horn
making the same sound the whole time. The change
we hear is caused by Doppler shift.
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7. Echo and Doppler Shift combined:
 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 moving.
 This technique can also be used in SOund Navigation
And Ranging (SONAR).
 Used in boats and submarines (Ultrasonic waves).
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8. How are Airplanes Measured?
 The RADAR antenna burst out a
stream of radio waves, which are
then reflected back by any object it
happens to encounter.
 The RADAR antenna measures the
time it takes for the reflection to
arrive, and with that information
we can tell how far away the object
is.
 The metal body of an airplane is
very good at reflecting RADAR
signals, and this makes it easy to
find and track airplanes with
RADAR equipment.
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9. HISTORY OF STEALTH
TECHNOLOGY:
• The first true "stealth" aircraft
may have been the
Horten Ho 229 flying
wing fighter-bomber, developed
in Germany during the last years
of World War 2.
• SR 71 was the first Stealth
airplane launched. It is well
known as 'black bird'.(Secret
Project)
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10. CONVENTIONAL VS STEALTH
AIRCRAFT:
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11. Stealth Technology:
 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 if
any RADAR signals hits the surface
of the aircraft, it gets reflected away
from the RADAR source.
The airplane can be covered with
materials that absorb RADAR
signals.
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12. RAS: RADAR Absorbent
Surfaces
• Deflects incoming RADAR waves.
• Reduces the detection range.
• Wing edges are designed to scatter incoming waves.
• Surfaces should not have 90 degree angles.
F-117 “Night Hawk”
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13. • Absorbs RADAR signals.
• Depends on the material of the surfaces.
• Believed to be silicon based organic compound.
RAM: RADAR Absorbent Material
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14. Advantages:
 Reduces the causality rates during the wars.
 Saves the military budget.
 Great importance in anti-terrorist operations.
 Bluff the anti-detective device.
LCA Tejas
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15. Disadvantages:
 Stealth aircraft cannot fly fast.
 They carry reduced amount of payload.
 Cost of investment and maintenance are very high.
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16. COST:
F-22 Bomber
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17. Future of Stealth Technology:
 In the future, stealth
technology will not only be
incorporated in fighters and
bombers but also in ships,
helicopters, tanks and
transport planes.
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18. Plasma Stealth:
 In Plasma stealth, the aircraft injects a stream of
ionized gas which envelopes the aircraft.
 Due to this most of the radio waves are absorbed
which makes the aircraft completely invisible.
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19. CONCLUSION:
 Stealth technology is the future of military combat technology.
 In near future, Stealth technology can also be used in ships,
helicopters and other vehicles.
 The main problem of this technology is its high cost.
 Due to its high cost, it is not suitable for economically
backward countries.
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20. REFERENCES:
 RAY WHITFORD, Designing For Stealth In
Fighter Aircraft, CRANFIELD UNIVERSITY
 www.fas.org
 www.airforce-technology.org
 www.discovery.com
 International Journal of Research In Science &
Engineering: Volume: 1 Issue: 2
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21. THANK YOU!
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