A Technical Paper Presentation

On

STEALTH TECHNOLOGY

A SEMINAR ABSTRACT SUBMITTED BY

NAME : V.SATYA KISHORE

REGD NO: 10A21D5713

ABSTRACT

Stealth technology has as its fundamental principle the prevention of detection by

the enemy, and applies not only to aircraft as is commonly assumed, but also increasingly

to naval vessels and to armored vehicles, although in the latter cases, it is emerging

technology upon which comment must be reserved. Stealth technology, therefore, does

not simply mean the evasion by aircraft of radar through the reduction of radar signature.

It also encompasses the reduction of an aircraft's visibility in other spectra, most notably

acoustic, visual, and infra-red. Consequently the popular term ‘stealth technology’

would perhaps be better referred to as ‘low-observable technology’.

Stealth technology provides its users with a number of strategic advantages. As

well as allowing the penetration of heavily defended airspace, it enables single aircraft to

carry out attacks in a manner impossible for conventional aircraft, which require a large

number of support aircraft to conduct similar missions, including escort, defense

suppression, and electronic warfare types. A conventional aircraft ‘package’ may employ

up to 40 aircraft, while a stealth aircraft can conduct the mission by itself. This naturally

requires the use of precision-guided weapons to ensure that the single aircraft has a high

probability of success.

Stealth is not without its drawbacks. The cost of the technology is enormous, and

it is hard to predict that its eventual employment in marine and land operations will ever

be obtained at a price comparable to conventional technology. Nonetheless, precisely

because of its elevated cost it does emphasize the economic power of the contry as well

as its immense advantage in science and technology over the rest of the world.

SUPERVISOR M TECH CO-ORDINATOR HOD(ECE)

Topics to be discussed:

Introduction

What is the need of "STEALTH TECHNOLOGY”

Anatomy of RADAR TECHNOLOGY

History of Stealth Technology

RADAR Stealth

Absorption

Deflection

Counter Stealth

Anti Stealth Technology

Methods of Anti Stealth Technology

Airborne method

Satellite Based Method

Surface Based Method

Advantages

Conclusion

INTRODUCTION

WHAT IS STEALTH? In simple terms, stealth technology allows an aircraft to be partially invisible to

Radar or any other means of detection. This doesn't allow the aircraft to be fully invisible

on radar. Stealth technology cannot make the aircraft invisible to enemy or friendly radar.

All it can do is to reduce the detection range or an aircraft. This is similar to the

camouflage tactics used by soldiers in jungle warfare. Unless the soldier comes near you,

you can't see him. Though this gives a clear and safe striking distance for the aircraft,

there is still a threat from radar systems, which can detect stealth aircraft.

Radar is something that is in use all around us, although it is normally invisible.

Air traffic control uses radar to track planes both on the ground and in the air, and also to

guide planes in for smooth landings. Police use radar to detect the speed of passing

motorists. NASA uses radar to map the Earth and other planets, to track satellites and

space debris and to help with things like docking and maneuvering. The military uses it to

detect the enemy and to guide weapons.

ANATOMY OF RADAR TECHNOLOGY:

Meteorologists use radar to track storms, hurricanes and tornadoes. You even see

a form of radar at many grocery stores when the doors open automatically! Obviously,

radar is an extremely useful technology. When people use radar, they are usually trying to

accomplish one of three things:

(a) Detect the presence of an object at a distance - Usually the "something" is

moving, like an airplane, but radar can also be used to detect stationary objects buried

underground. In some cases, radar can identify an object as well; for example, it can

identify the type of aircraft it has detected.

(b) Detect the speed of an object - This is the reason why police use radar.

(c) Map something - The space shuttle and orbiting satellites use something

called Synthetic Aperture Radar to create detailed topographic maps of

the surface of

All three of these activities can be accomplished using two things you may be

familiar with from everyday life: echo and Doppler shift. These two concepts are easy to

understand in the realm of sound because your ears hear echo and Doppler shift every

day. Radar makes use of the same techniques using radio waves.

What is the need of "STEALTH TECHNOLOGY”

Air operations have provided many advantages in warfare, resulting

in the extensive use of aircraft to dominate the battlefield. The mission

benefits of aircraft include flexibility, mobility and speed, and have given users rapid,

massive, effective and surprise attack opportunities on remote territories.

However if an aircraft does not employ tactics and technologies that improve

its survivability it will be vulnerable to counter attack. In general,

survivability, which improves with these tactics and technologies,

“depends on a complex mix of design features, performance, mission

planning and tactics.”

Stealth aircraft are specifically designed with the aforementioned features

and performance qualities to increase survivability, which means accomplishing the

mission objectives and returning home safely. Thus, stealth capability has a very high

importance in the battlefield. Further, stealth aircraft are able to accomplish

and survive missions where other assets cannot. Their operational flexibility

provides users the ability to penetrate even the most well defended zones with

relatively little risk.

In warfare, detection of enemy forces is vital for counter attack and defenders are

made aware of an attacker’s air operations by means of several types

of detectors, especially radars. For instance, in air operations, defenders have

more time to deploy interceptors and other ground forces after early

detection by radars. Defensive forces attempt to defeat an opponent’s

attacks by using counter weapon systems.

Further, defenders may have sufficient time to take precautions in the targeted

zone to reduce or eliminate the effectiveness of a campaign. On the other hand, low

observable technology enhances air superiority and the freedom to attack surface targets

by means of reducing an aircraft’s radar detection range and its infrared, visual

and acoustic signatures to degrade the chance and range of detection .

Thus, ideal stealth technology assets enable its users to operate freely and conduct

missions securely, even in the most risky enemy zone.

Though it is not possible to become completely stealthy, either

delaying the detection or lessening an opponent’s ability to track target course after

detection provides a major advantage to low observable users.

Development of stealth technology for aircraft began before World War I.

Because RADAR had not been invented, visibility was the sole concern, and the goal was

to create aircraft that were hard to see. In 1912, German designers produced a largely

transparent

History of Stealth Technology:

monoplane; its wings and fuselage were covered by a transparent material

derived from cellulose, the basis of movie film, rather than the opaque canvas standard in

that era. Interior struts and other parts were painted with light colors to further reduce

visibility. The plane was effectively invisible from the ground when flow at 900 ft (274

m) or higher, and faintly visible at lower altitudes. Several transparent German aircraft

saw combat during World War I, and Soviet aircraft designers attempted the design of

transparent aircraft in the 1930s.

With the invention of RADAR during World War II, stealth became both more needful

and more feasible: more needful because RADAR was highly effective at detecting

aircraft, and would soon be adapted to guiding antiaircraft missiles and gunnery at them,

yet more feasible because to be RADAR-stealthy an aircraft did need to be not be

completely transparent to radio waves; it could absorb or deflect them.

During World War II, Germany coated the snorkels of its submarines with

RADAR-absorbent paint to make them less visible to RADAR’s carried by Allied

antisubmarine aircraft. In 1945 the U.S. developed a RADAR-absorbent paint containing

iron. It was capable of making an airplane less RADAR-reflective, but was heavy;

several coats of the material, known as MX-410, could make an aircraft unwieldy or even

too heavy to fly. However, stealth development continued throughout the postwar years.

In the mid 1960s, the U.S. built a high-altitude reconnaissance aircraft, the Lockheed SR-

71 Blackbird, which was extremely RADAR-stealthy for its day. The SR-71 included a

number of stealth features, including special RADAR-absorbing structures along the

edges of wings and tailfins, a cross-sectional design featuring few vertical surfaces that

could reflect RADAR directly back toward a transmitter, and a coating termed "iron ball"

that could be electronically manipulated to produce a variable, confusing RADAR

reflection. The SR-71, flying at approximately 100,000 feet, was routinely able to

penetrate Soviet airspace without being reliably tracked on RADAR.

The Russian 1R13 radar system is very much capable of detecting the F-117

"Night Hawk" stealth fighter. There are also some other radar systems made in other

countries, which are capable of detecting the F-117. During the Gulf war the Iraqis were

able to detect the F-117 but failed to eliminate its threat because of lack of coordination.

The most unforgettable incident involving the detection and elimination of a stealth

aircraft was during the NATO air-war over Yugoslavia. This was done by a Russian built

"not so advanced" SAM (possibly the SA-3 or SA-6). The SAM system presumably used

optical detection for target acquisition in the case.

Radar Principles:

RADAR INVISIBILITY: DESIGNING A "STEALTH” AIRCRAFT:

Radar is an electromagnetic system for the detection and location of

reflecting objects such as aircraft, ships, spacecraft, vehicles, people, and

the natural environment. The word RADAR came from using the capitalized letters of the

phrase Radio Detection and Ranging. The wide spread military use of it during WWII

changed the progress of the war. It later became an indispensable navigation and traffic

control system for civilian purposes.

Radar uses the principle of sending a radar wave, which is a form of

electromagnetic radiation, in a desired direction with a transmitter, and then collecting the

reflected signals from a target with a receiver. Once reflected signals are received, the

range to a target can be calculated by evaluating the interval of the radar signal’s travel;

the half time of total interval gives the distance of the target while the radar signal

propagates from the transmitter and returns to the receiver after reflection from the target.

This study is not intended to discuss complex radar principles, however, the

fundamental mathematical model of the radar equation can be useful in understanding the

important relationship between the main variables; radar cross section of the target,

frequency and effective radiated power of the radar, distance between the transmitter,

target and receiver. The radar equation is expressed as

where Pr (watts) is the attained power by the radar receiver, Pt (watts) is the transmitted

power from the radar emitter, Gt and Gr (unit less) are the gains of the transmitter and the

receiver that generates the multiplier for the effective power, σ (square meters) is radar

cross section (RCS) and λ (meters) is the wavelength. Wavelength can be calculated by

using the formula:

where c equals to, 3x108 (meters per seconds), because the signal radiates at the speed of

light, and f is the radiated signal’s frequency (Hertz). As the detection range is very

important for a low observable aircraft, the statement for the range acquired from

Equation below should be analyzed.

As seen in above Equation, detection distance varies by the quarter root of RCS.

Because the only factor which can be changed by a low observable aircraft designer is

RCS, it becomes crucial. However, the fact that reduction in the RCS decreases only by

the fourth root of the distance, requires designers to be very careful, because only

dramatically large changes in RCS give favorable results. If a given radar has a detection

range of 100 miles against a target with a RCS of 10 m2, its approximate detection range

to different RCS values calculated with basic radar equation are shown in Table. This

results again show that, only enormous reductions in the RCS can make significant

changes in the detection range

A target is detected by the radar only when the radar’s receiver gets adequate

Importance of Radar Cross Section (RCS) and RCS Reduction Methods:

energy back from the target, furthermore, this energy must be above the electronic noise

or signal to noise threshold to be detected. There are many variables in the transmission

scattering reflection sequence which determine the maximum detection range. These are

transmitter effective outgoing energy, beam width, RCS of the target, total energy back

from the target, antenna aperture (or size) and the receiver’s processing capability .

Among these variables, RCS is the main concern of this study. A radar beam is

shaped in 3 dimensions like a cone, so as the range increases, the area seen by this cone

increases. However, with this increased range, the reflected target energy and detected

receiver energy reduce. So, even in the best of circumstances, only a small portion of the

original energy can be used by the radar to process.

Increasing the radar transmitter power or deploying bigger antennas with more

gain helps to obtain a longer detection range. However, these approaches have

limitations, such as increased cost and an increase in noise back to the system. Most of

the cost for an increase in energy is wasted on empty space. Furthermore, larger antennas

and larger energy generating units are unmanageable, especially for mobile systems.

Nevertheless, with a good understanding of basic electromagnetic principles and radar

phenomena, sophisticated radar designs that have better detection performance and

greater precision are being developed

Up to this point, only the radar designer’s concerns are mentioned. For the stealth

designer, the only variable to decrease the detection range is RCS. This is why RCS is the

key term for low observables where reduction in reflected RF signal signature is

intended. Any attempt to make an asset RF low observable focuses on RCS. If a target’s

RCS can be decreased to a level low enough for its echo return to be below the detection

threshold of the radar, then the target is not detected. In this context, RCS reduction is a

countermeasure which has developed against radars and, conversely, new radar

techniques with more sophisticated designs are produced to detect targets with low RCS

Radar cross section is the size of a target as seen by the radar. In more scientific words,

RCS is a measure of the power that is returned or scattered in a given direction,

normalized with respect to power density of the incident field. The normalization is made

to remove the effect of the range, and so the signature is not dependent on the distance

between the target and the receiver. The RCS helps to measure objects against a common

reference point, which is very useful in the low observable technology world in

determining the performance of design goals. In this context, RCS can also be described

as the size of a reflective sphere that would return the same amount of energy back. The

projected area of the sphere, or the area of a disk of the same diameter, is the RCS

number itself. However, one important thing that should be understood is that this area is

not the geometrical cross section of the body.

Considering the first two factors, which are under control of the stealth designer,

there are four main principles to reduce the RCS of an airplane. The principles are

designing the shape, using special materials (RAM) on the surfaces, active cancellation

and passive cancellation. In addition, a fifth consideration is plasma technology, which is

also sometimes included as an active cancellation type.

RADAR Stealth

RADAR is the use of reflected electromagnetic waves in the microwave part of

the spectrum to detect targets or map landscapes. RADAR first illuminates the target, that

is, transmits a radio pulse in its direction. If any of this energy is reflected by the target,

some of it may be collected by a receiving antenna. By comparing the delay times for

various echoes, information about the geometry of the target can be derived and, if

necessary, formed into an image. RADAR stealth or invisibility requires that a craft

absorb incident RADAR pulses, actively cancel them by emitting inverse waveforms,

deflect them away from receiving antennas, or all of the above. Absorption and

:

deflection, treated below, are the most important prerequisites of RADAR stealth.

Metallic surfaces reflect RADAR; therefore, stealth aircraft parts must either be

coated with RADAR-absorbing materials or made out of them to begin with. The latter is

preferable because an aircraft whose parts are intrinsically RADAR-absorbing derives

Absorption:

aerodynamic as well as stealth function from them, whereas a RADAR-absorbent coating

is, aerodynamically speaking, dead weight. The F-117 stealth aircraft is built mostly out

of a RADAR-absorbent material termed Fibaloy, which consists of glass fibers embedded

in plastic, and of carbon fibers, which are used mostly for hot spots like leading wing-

edges and panels covering the jet engines. Thanks to the use of such materials, the

airframe of the F-117 (i.e., the plane minus its electronic gear, weapons, and engines) is

only about 10% metal. Both the B-2 stealth bomber and the F-117 reflect about as much

RADAR as a hummingbird

Many RADAR-absorbent plastics, carbon-based materials, ceramics, and blends of these

materials have been developed for use on stealth aircraft. Combining such materials with

RADAR-absorbing surface geometry enhances stealth. For example, wing surfaces can

be built on a metallic substrate that is shaped like a field of pyramids with the spaces

between the pyramids filled by a RADAR-absorbent material. RADAR waves striking

the surface zigzag inward between the pyramid walls, which increases absorption by

lengthening signal path through the absorbent material. Another example of structural

absorption is the placement of metal screens over the intake vents of jet engines. These

screens—used, for example, on the F-117 stealth fighter—absorb RADAR waves exactly

like the metal screens embedded in the doors of microwave ovens. It is important to

prevent RADAR waves from entering jet intakes, which can act as resonant cavities

(echo chambers) and so produce bright RADAR reflections.

The inherently high cost of RADAR-absorbent, airframe-worthy materials makes stealth

aircraft expensive; each B-2 bomber costs approximately $2.2 billion, while each F-117

fighter costs approximately $45 million; the U.S. fields 21 B-2s and 54 F-117s. The

Russian Academy of Sciences, however, according to a 1999 report by Jane's Defense

Weekly, claims to have developed a low-budget RADAR-stealth technique, namely the

cloaking of aircraft in ionized gas (plasma). Plasma absorbs radio waves, so it is

theoretically possible to diminish the RADAR reflectivity of an otherwise non-stealthy

aircraft by a factor of 100 or more by generating plasma at the nose and leading edges of

an aircraft and allowing it flow backward over the fuselage and wings. The Russian

system is supposedly lightweight (>220 lb [100 kg]) and retrofit table to existing aircraft,

making it the stealth capability available at least cost to virtually any air force.

A disadvantage of the plasma technique that it would probably make the aircraft

glow in the visible part of the spectrum.

Most Radar are monotonic, that is, for reception they use either the same antenna

as for sending or a separate receiving antenna collocated with the sending antenna;

deflection therefore means reflecting RADAR pulses in any direction other than the one

they came from. This in turn requires that stealth aircraft lack flat, vertical surfaces that

could act as simple RADAR mirrors. RADAR can also be strongly reflected wherever

three

Deflection:

planar surfaces meet at a corner. Planes such as the B-52 bomber, which have many

flat, vertical surfaces and RADAR-reflecting corners, are notorious for their RADAR-

reflecting abilities; stealth aircraft, in contrast, tend to be highly angled and streamlined,

presenting no flat surfaces at all to an observer that is not directly above or below them.

The B-2 bomber, for example, is shaped like a boomerang.

A design dilemma for stealth aircraft is that they need not only to be invisible to RADAR

but to use RADAR; inertial guidance, the Global Positioning System, and laser RADAR

can all help aircraft navigate stealthily, but an aircraft needs conventional RADAR to

track incoming missiles and hostile aircraft. Yet the transmission of RADAR pulses by a

stealth aircraft wishing to avoid RADAR detection is self-contradictory. Furthermore,

RADAR and radio antennas are inherently RADAR-reflecting.

A Stealthy Air Craft

An aircraft cannot be made truly invisible. For example, no matter how cool the

exhaust vents of an aircraft are kept, the same amount of heat is always liberated by

burning a given amount of fuel, and this heat must be left behind the aircraft as a trail of

warm air. Infrared-detecting devices might be devised that could image this heat trail as it

formed, tracking a stealth aircraft.

Counter-stealth:

Furthermore, every jet aircraft leaves swirls of air—vortices—in its wake. Doppler radar,

which can image wind velocities, might pinpoint such disturbances if it could be made

sufficiently high-resolution.

Other anti-stealth techniques could include the detection of aircraft-caused disturbances

in the Earth's magnetic field (magnetic anomaly detection), networks of low frequency

radio links to detect stealth aircraft by interruptions in transmission, the use of specially

shaped RADAR pulses that resist absorption, and netted RADAR. Netted RADAR is the

use of more than one receiver, and possibly more than one transmitter, in a network.

Since stealth aircraft rely partly on deflecting RADAR pulses, receivers located off the

line of pulse transmission might be able to detected deflected echoes. By illuminating a

target area using multiple transmitters and linking multiple receivers into a coordinated

network, it should be possible to greatly increase one's chances of detecting a stealthy

target. No single receiver may record a strong or steady echo from any single transmitter,

but the network as a whole might collect enough information to track a stealth target.

Modern military stealth technology is based on the principle that stealthy craft

remain invisible to detecting radar and infrared sensors, especially at long ranges. Such

technology can be entirely nullified by the detecting radar and/or infrared sensors

searching, not for the stealthy craft itself, but for the background behind the stealthy craft.

The stealth craft will then show up in the form of a black or blank silhouette in front of

the background. This is much like the way one can pinpoint with extreme accuracy the

location of the moon during a solar eclipse, and track its movement with great precision,

even though during a solar eclipse one cannot observe the moon itself. (N.B.: The

remainder of this document describes the detailed methods one might use to detect

ANTI-STEALTH TECHNOLOGY:

the background behind stealth craft. Thus it is not necessary to read the entire document

in order to grasp the principle of Anti-Stealth Technology, though one may of course do

so to dispel all skepticism as to its practicability.)

Military stealth technology, such as is used, for example, in the B-2 bomber, the F-

117fighter-bomber and the F-22 fighter, and as is intended for the future Comanche

helicopter, and the next-generation tank which is intended to replace the current M1A2

Abrams tank — is based on the principle that the stealthy craft remains invisible to

detecting radar and infrared sensors, especially at long ranges. With respect to radar, this

is accomplished, in basic principle, by the stealthy craft absorbing almost all the radar

waves emanated by detecting radar sources, and/or reflecting or deflecting the detecting

radar in direction(s) other than towards the detecting sensors. With respect to infrared, the

objective of stealth is achieved, in basic principle, by the stealthy craft minimizing heat

from its engines and other heat-emitting spots. As a result of applying the above

principles, detecting sensors searching for a stealthy craft cannot detect any radar or

infrared signal emanating from the craft, except perhaps at very close distances, when it

may already be too late to do anything about it from a military viewpoint. The craft,

therefore, cannot be observed by radar or infrared sensors.

Basic Principles of Modern Stealth Technology:

One way to accomplish the above is for the detecting forces to fly a high-flying aircraft

furnished with SLAR (Side-Looking Airborne Radar) and/or FLIR (Front-Looking

Infra-Red) equipment to map out the terrain below and to one side, or to the front. If a

stealth craft were operating anywhere above the terrain being mapped, a small patch of

terrain, which the stealth craft would perforce eclipse, would not be observed on the

detecting aircraft’s output screen. That particular spot would appear black or blank, and

more or less in the shape of a silhouette of the stealth craft: thereby pinpointing the

stealth craft’s position within the field of vision of the detecting aircraft. The initial

detection of a distant stealth craft might be slow, since until the craft were detected,

1. Airborne Method

the equipment would have to scan the entire terrain over which the craft might be located.

However, once that location were pinpointed, the craft could be tracked much more

swiftly and accurately by zooming in on that location and some of its surrounding area,

and scanning only that relatively small part of the field of vision. This would enable the

searching equipment to generate much more detailed images of the silhouette of the craft

in question, perhaps even identifying the craft by that silhouette. If, in addition, the SLAR

or FLIR equipment were furnished with rangefinder capability (as many such are), the

exact position of the stealth craft in three dimensions could also be determined. This

would not greatly matter, of course, if the stealth craft were a land vehicle (like a tank);

but in the case of aircraft such data could provide very valuable information from a

military point of view. And with modern computers this position could be calculated very

swiftly indeed: almost instantaneously.

The same method may be used looking down on the battlefield from satellites equipped

with radar sensors. Although satellites would be relatively far away from the battlefield a

couple of hundred miles away, or even more — they would be able to remain out of

range of most hostile weapons, and thus would not run much risk of being shot down, as

might aircraft. Also, satellites would be able to cover a much larger area of the battlefield,

thus being in a position to locate and track virtually all hostile stealth craft.

2. Satellite-Based Method

Yet another way of detecting a stealth aircraft would be for surface-based radar

installations to scan the sky at high apertures and with high sensitivity, such as is done

with radio telescopes. (Since such installations would be surface-based, even if they had

to be substantially large and/or heavy to adequately accomplish this task, their size and

weight would not be a serious deterrent to their accomplishing it.) As is well known to

radio astronomers, even in daytime or in bad weather, radio signals from the stars would

reach the radar installations uninterrupted. Since the radio map of the stars is by now very

well known, it may be assumed that if any star is not observed on the detecting screen or

output device, that particular star must be eclipsed by some craft flying above the

installation somewhere along the line of sight between the installation and that particular

star. And with very sensitive radio-astronomical equipment, virtually every part of the

sky is observed to be covered with stars! Therefore at almost every instant in time, the

3. Surface-Based Method

stealth aircraft would be eclipsing one or another known star. Even if less sensitive

detecting equipment were used, so that the time it took to record the stellar images was

greater than the time it took for an aircraft to entirely eclipse a particular star, that star

would still show up on the detecting screen somewhat fainter than it would otherwise if it

had not been eclipsed by the aircraft for a part of the time it took for the radio waves from

it to be gathered. Thus by calibrating the detecting equipment to search for those stars

whose radio images appear to be fainter than usual (as determined by standard radio maps

of the sky), the position of the eclipsing aircraft could be determined swiftly, even with

equipment of less than stellar performance. Indeed the limit of sensitivity of the

equipment as a whole would be determined, not by the sensitivity of the radio signal

gathering device, but by the sensitivity of the equipment which detects the difference in

intensity of the actual signals from particular stars compared to their intensity as

indicated by the standard radio map of those same stars. And as with the airborne

method, although the initial detection of a distant stealth aircraft might be slow, once its

location were pinpointed, the aircraft could be tracked much more swiftly and accurately

by zooming in on that location and some of surrounding area. If more than one detecting

installation were used, by a process of triangulation the exact location in three dimensions

of all aircraft — friendly as well as hostile — within the fields of vision of the relevant

installations could be determined with great accuracy. And as mentioned earlier, with

Modern computers such a determination could be arrived at almost instantaneously.

With the passage of time, the specific stars being eclipsed by any particular aircraft

would change in a manner consistent with the aircraft’s trajectory. Thus by accurately

observing the time intervals between sequentially-eclipsed stars, coupled with an exact

knowledge of the radio-astronomical map, the aircraft’s trajectory could easily and

quickly — almost instantly — be calculated, especially if powerful computers were

utilized to calculate it. If, in addition, the locations of all the friendly aircraft within the

field of vision of the installation are also known, it may be assumed that hostile aircraft

must be eclipsing those stars not showing up on the screen which cannot be accounted for

by friendly aircraft. Thus by a process of elimination, the location of all hostile aircraft,

and not just hostile stealth aircraft, could be determined. This would be an advantage of

the surface-based method as opposed to the airborne method described earlier. And, of

course, with modern computers all the above calculations could be performed extremely

rapidly: almost instantaneously.

One further advantage of the surface-based method, as opposed to the airborne

method described earlier, is that the detecting installation(s) need not emit any radio

signals themselves. Thus it would be impossible for hostile aircraft to home in on their

radio emissions in order to destroy the installations, which add to their safety factor:

especially if from a visual point of view these installations were also carefully

camouflaged.

Further Advantages of the Surface-Based Method:

Another advantage of the surface-based installations would be that they could also be

equipped with powerful surface-to-air missiles (SAMs), which could be much larger and

possess much greater range and destructive power than air-based missiles for the

destruction of hostile stealth aircraft. And since these particular SAMs need not

themselves emit any radar signals either, but could

merely fly along a narrow beam (say, a laser beam) emanating from the installation

which has detected the stealth aircraft, the latter would get no warning that one or more

SAMs have been launched against it, and thus would not have a chance to take evasive

action.

Both technology and skills goes hand in hand so that those who possess better technology

and skills will definitely win the war or detect the missiles or aircrafts. You might think

that this technology was related to our department only but it is a core technology related

to several disciplines of technology.

Conclusion:

Unlikely such new kinds of stealth technology can be developed in so short a time.