The Radar Game : Understanding Stealth and Aircraft Survivability.

[monitor]

FORWARD
Radio aids to detection and ranging ... radar—as it’s
commonly called—transformed air warfare in 1940. It
has held a grip on would-be attackers and defenders ever
since.
This special report from the Mitchell Institute for Airpower
Studies is a republication of a long essay I wrote in 1998 to
get at why stealth was such an important breakthrough for
airpower. Then, as now, there were questions about the future
of stealth.
Consider the times. The dazzling combat success of the
F-117 in the Gulf War of 1991 had been followed by the cancellation
of the B-2 stealth bomber program in 1992. Cuts to
the F-22 stealth fighter program had already been made. Experienced
airmen were strongly in favor of stealth. Some officials,
like former Secretary of Defense William Perry and then-
Undersecretary of Defense for Acquisition Paul Kaminski, were
thoroughly steeped in the workings of stealth and its benefits.
But for many, intricate stealth programs seemed a questionable
investment given the declining defense budgets of the
late 1990s. Stealth was wrapped up in the value of airpower as
a whole and in the re-evaluation of American security policies.
Still, a dozen years ago there was a strong commitment
to stealth. The Air Force, Navy, and Marine Corps along with
Britain had committed to the Joint Strike Fighter. Teams led by
Lockheed Martin and Boeing were working on designs. Perhaps
most important, the long-range Air Force budget had
a plan to field an all-stealth fighter force of more than 2,200
fighters. The future of stealth seemed assured.
Combat experience quickly revalidated its importance
during the 1999 NATO air war with Serbia. B-2s flew missions
into heavily defended airspace and did everything from taking
out the Novi Sad bridge to attacking and destroying an
SA-3 surface-to-air missile battery. F-117s flew crucial missions.
(One F-117 was shot down.) The intensive air war with Iraq in
early 2003 again saw the use of both F-117s and B-2s against
a variety of targets in and around Baghdad.
Since then, stealth has come under assault. The reasons
have much to do with strategy, politics, and budgets, and
little to do with the capability assessments that drove the decisions
to develop and buy stealth aircraft in the first place.
The radar game itself is just as critical as it was a dozen
years ago. Radar remains the leader in technologies for detecting
aircraft and missile attack. As the study notes: “Why
were aircraft so vulnerable to radar detection? In short, for all
the reasons that increased their aerodynamic qualities and
performance. Metal skins, large vertical control surfaces, big
powerful engines” and so on.
The study details how the first rounds of the radar game
were all about electronic countermeasures. RAF Bomber
Command famously held back the first use of chaff for over
a year, fearing that the Germans would implement countermeasures,
too. During the Cold War, electronic countermeasures
and electronic counter-countermeasures became one
of the blackest arts of airpower and one of its most important.
Stealth was in part a way to break the tug-of-war.
That was why stealth was so attractive. Attackers must
undo the adversary’s advantage either by low-level ingress,
high-altitude operations, speed, electronic countermeasures,
or stealth. Of these, the ability to diminish the effects of
radar return is one of the most challenging and one of the
most rewarding. A low observable aircraft gains advantages
in how close it can come to air defense systems. Low observable
aircraft do not get a free pass in the battlespace.
Low observability has to be fine-tuned to defeat adversary
systems as they establish and hand-off tracks and zero in on
fire control solutions. Not much will prevent the big bump of
long-range, low frequency radars used for initial detection.
But, it takes much more than a blip on a “Tall King” radar to
unravel a well-planned mission.
Over the past decades, it’s never been easy to convey
what low observable technologies actually do. Understanding
them requires some grasp of physics, of radar phenom-
Foreword
7
A MITCHELL INSTITUTE STUDY
enology, of aircraft design, of how missions are planned and
executed. One hears so often that stealth is not invisibility.
The inverse corollary is that a single radar detection of an
aircraft at a point in time and space does not equal an impenetrable
battlespace. The British nickname “Chain Home”
for their cross-Channel radar suite had it about right. It takes
a chain of detections, interpretations, and correct actions
by defenders to intercept an aircraft. Stealth breaks up the
chain by removing, reducing, or obfuscating a significant
percentage of those detection opportunities.
Much of The Radar Game is devoted to a basic discussion
of how stealth works and why it is effective in reducing
the number of shots taken by defensive systems. Treat this
little primer as a stepping off point for discovering more of
the complexities of low observability.
Of course, there is a wider electromagnetic spectrum to
consider. While radar is the focus here, true survivability depends
on taking measures to reduce visual, acoustic, and
infrared signatures as well as minimizing telltale communications
and targeting emissions.
The darling of passive technologies is infrared search and
track. Those in combat ignore the infrared spectrum at their
peril. Although it is not as often in the headlines, designers
of all-aspect stealth aircraft have worked since the 1970s to
minimize infrared hotspots on aircraft.
Finally, electronic countermeasures still have their role to
play. As before, it will take a combination of survivability measures
to assure mission accomplishment.
The Radar Game should also shed light on why complex
technologies like stealth cost money to field. The quest for
stealth is ongoing and the price of excellence is nothing
new. Take, for example, the P-61 Black Widow, which was the
premier US night fighter of late World War II. This all-black,
two-engine fighter was crewed by a pilot in front and a
dedicated radar operator in the back seat. Its power and
performance were terrific advances. “All this performance
Original Copyright 1998 Rebecca Grant
Acknowledgements from 1998 version: The author would like
to thank Dr. Scott Bowden for his assistance with historical research.
Also, the author would like to extend special thanks to
Tom McMahon, Phil Soucy, Ken McKenzie, and Charles Massey
of Modern Technology Solutions International, of Alexandria, VA,
for conducting the simulations of signature shapes in an air defense
environment to illustrate the tactical benefits of stealth.
came with a high pricetag,” noted Steven L. McFarland in his
1997 Air Force history Conquering the Night. “With Northrop’s
assembly line in full gear, a completely equipped P-61 cost
$180,000 in 1943 dollars, three times the cost of a P-38 fighter
and twice the price of a C-47 transport.”
Winning the radar game still carries a substantial price
tag—but stealth aircraft pay back the investment in their
combat value.
Stealth remains at the forefront of design. One of the best
signals about the ongoing value of stealth lies in new applications.
Leading unmanned aerial vehicles for high-threat
operations incorporate stealth. Navy ships have adopted
some of its shaping techniques. Of course, the F-35 Joint
Strike Fighter remains the nation’s single biggest bet on future
airpower.
Success in the radar game will continue to govern the
value of airpower as a tool of national security. Many of
America’s unique policy options depend upon it. When and
if the SA-20 joins Iran’s air defense network, it will make that
nation a considerably tougher environment for air attack, for
example. Already there are regions of the world where only
stealth aircraft can operate with a good chance of completing
the mission.
In fact, stealth aircraft will have to work harder than ever.
The major difference from 1998 to 2010 is that defense plans
no longer envision an all-stealth fleet. The Air Force and joint
partners will operate a mixture of legacy, conventional fighters
and bombers alongside stealth aircraft even as the F-35s
arrive in greater numbers. The radar game of 2020 and 2030
will feature a lot of assists and the tactics that go along with
that.
Rebecca Grant, Director
Mitchell Institute for Airpower Studies
September 2010

 

[monitor]

INTRODUCTION
Precision weapons and rapid targeting information
mean little if aircraft are unable to survive engagements
with enemy air defenses. In addition to costing the lives of pilots,
high levels of attrition can ultimately affect the outcome
of the theater campaign. One of the most critical factors in
determining the success of an air operation is survivability. In
the last several decades, the term survivability has been associated
with analysis of how low observables and electronic
countermeasures can help aircraft carry out their missions
in hostile airspace. Discussions of survivability immediately
bring to mind stealth aircraft, radar jamming and debates
about the latest SA‑10 threats. Yet the quest for survivability
is not a fad of the Cold War or the high‑technology 1990s. Its
roots, and its importance to combined arms operations, go
back to the first use of military aircraft in World War I.
Since the earliest days of military aviation, pilots and
planners have taken advantage of whatever their aircraft
can offer to increase the odds of survivability. Aircraft survivability
depends on a complex mix of design features, performance,
mission planning, and tactics. The effort to make
aircraft harder to shoot down has consumed a large share
of the brains and resources dedicated to military aircraft design
in the 20th century.
Since the 1970s, the Department of Defense has focused
special effort on research, development, testing, and
production of stealth aircraft that are designed to make it
harder for air defenses to shoot them down. Low observable
(LO) technology minimizes aircraft signature in radar, infrared,
visual, and acoustic portions of the electromagnetic
spectrum, creating stealth. Future plans for the Air Force F‑22
and the tri‑service Joint Strike Fighter call for the nation to
continue to procure advanced, LO aircraft for the military of
the 21st century.
This essay tells the story of how the balance between the
air attacker and air defender has shifted over time, and how
the radar game changed the nature of aircraft survivability.
Examining the evolution of this balance provides a better
understanding of the choices facing military commanders
and defense planners as they consider what forms of survivability
technology are needed to preserve the dominance
of American airpower.
To begin with, the financial and strategic investment
in stealth aircraft is one that not everyone understands.
Stealth technology was developed and tested in secret.
F‑117 stealth fighter squadrons were practicing night missions
in the Nevada desert several years before the Air Force
publicly acknowledged the aircraft’s existence. Even after
the F‑117’s impressive performance in the 1991 Gulf War,
an element of mystery and misunderstanding sometimes
surrounds the operations of stealth aircraft. The F‑117 and
the B‑2 stealth bomber have the ability to complete and
survive missions that other aircraft cannot. Still, for the most
part, the government has given only the most condensed
and superficial explanations of what these low observable
aircraft can do and why their mission is so important to joint
operations. In addition, the mechanics of radar cross section
(RCS) reduction and the effect of lower signatures in tactical
scenarios are seldom discussed.
This essay will reveal no technical secrets or surprises.
What it will do, however, is explain how the radar game became
a major factor in air combat; how LO technology
gained the upper hand in the radar game; and how the
operational flexibility provided by low observable aircraft
has become pivotal to effective joint air operations.
The Origins of Aircraft Survivability
Survivability—defined as the ability of the aircraft and
aircrew to accomplish the mission and return home—has always
been an important factor in determining the effectiveness
of air operations. Early in World War I, the use of aviation
forces in combat revealed that survivability considerations
would influence mission effectiveness. Efforts to improve
survivability quickly began to influence aircraft design as
specialized aircraft types emerged by 1915. The whole idea
of the Spad XIII fighter plane, for example, was to combine
maximum speed and maneuverability to dominate aerial
engagements. Bombers such as the German Gotha or the
British Handley Page had a different mission and accordingly
drew on different survivability measures. They relied on
self‑defense guns and armor plating for survivability since
their extra range and payload precluded making the most
of speed and maneuver.
As aircraft survivability started to contribute to aircraft
design, aircraft were becoming more important contributors
to combined operations with ground forces. Aircraft had to
be able to operate over enemy lines to reconnoiter, correct
artillery fire, and ward off enemy airplanes trying to do the
same. By 1918, aircraft were an important element of combined
arms operations because of their ability to extend
the battle deep behind enemy lines. “The attack of ground
objectives in the zone as far back of the enemy’s front lines
as his divisional posts of command often yields important
results,” noted a General Staff report in 1919. “The great mobility
and speed of airplanes make it possible to utilize day
bombardment tactically to influence an action in progress,”
continued the report.1
The last campaigns of World War I hinted that air superiority
would be necessary for the most effective ground operations,
but World War II made it an iron law. However, the
invention of radar on the eve of World War II changed the
aircraft survivability problem completely. In World War I, visual
detection in clear daylight did not exceed ranges of
10‑15 miles at best. Even in the late 1930s, defenders expected
to listen and watch for attacking aircraft.
By 1940, radar could spot incoming aircraft 100 miles
away. Early detection gave defenders much more time
to organize their air defenses and to intercept attacking
planes. Radar height‑finding assisted antiaircraft gunners
on the ground. Primitive airborne radar sets were installed in
night fighters in the later years of the war. The radar game
had begun. Gaining air superiority and the freedom to attack
surface targets while protecting friendly armies rested
on surmounting the advantages that radar gave to air defenses.
The stakes of the radar game also affected combined
arms operations in all theaters of the war. Hitler canceled
the invasion of Britain when the Luftwaffe failed to win
local air superiority over the English Channel coast in September
1940. The Allies hinged their plans for the Normandy
landings on gaining control of the air over Europe and exploiting
it with effective air interdiction. The rate at which airpower
could accomplish its objectives therefore depended
directly on survival rates of the bombers attacking aircraft
factories and industrial targets in Fortress Europe. Once the
Allies were ashore, they planned for airpower to help offset
the numerical superiority of German ground forces.
The Cold War made aircraft survivability even more complicated.
After WWII, radar technology leapt ahead and aircraft
designs struggled to maintain a survivability edge. By
the 1960s, radar dominated the air defense engagement.
Longer range detection radars provided ample early warning.
Radar‑controlled surface‑to‑air missiles (SAMs) improved
the speed and accuracy of attacks against aircraft. In the
air, more advanced radars and guided air‑to‑air missiles
changed the nature of aerial combat. Conventional performance
improvements in speed, altitude ceiling, maneuverability,
and other parameters pushed ahead but could not
keep pace with the most sophisticated air defenses. If radar
made aircraft easy to shoot down, the effectiveness of air
operations would plummet.
As a result, combat aircraft had to incorporate additional
survivability measures to stay ahead in the radar game.
Electronic countermeasures (ECM) to radar were first employed
in World War II. Research in the 1950s and 1960s led
to much more advanced countermeasures that disrupted
radar tracking by masking or distorting the radar return.
When aircraft got closer to the air defenses, however, their
radar reflections grew large enough to burn through the
electronic smokescreen put in place by ECM.
Winning the Modern Radar Game
In this context, the prospect of designing combat aircraft
that did not reflect as much radar return was an enticing
possibility. British researchers in the 1940s hypothesized
about foiling radar detection. Low observable technology
that reduced radar return would make it harder for defenders
to track and engage attacking aircraft because they
would not have as big an aircraft signature to follow. Less
radar return meant less time in jeopardy, or time in which
aircraft could be tracked and fired upon by other aircraft or
by ground‑based defenses.
However, coming up with an aircraft design that minimized
radar return depended on many factors. It was not
until the early 1970s that the physical principles of controlling
radar return were understood well enough to apply them
to aircraft design. Low observable technology was based
first on a sophisticated ability to understand and predict the
behavior of radar waves in contact with an aircraft.
Research into special shapes and materials made building
a low observable aircraft a reality. The aim was not to
make aircraft invisible, but to quantify and minimize key areas
of the aircraft’s radar return. Incorporating low observables
required trade‑offs that often appeared to go against
established principles of aerodynamic design. The primary
method for reducing radar cross section was to shape the
aircraft’s surface so that it deflected radar return in predictable
ways.
Variations in the angle from which aircraft approached
the radar, and the frequency of the radars used by the deTHE
RADAR GAME: Understanding Stealth and Aircraft Survivability
10
fenders, also affected the radar return and required choices
about how to optimize designs for the most dangerous parts
of the cycle of detection, tracking, and engagement. As
RCS diminished, other factors became important corollaries,
such as reducing the infrared signature as well as visual,
acoustic, and other electronic evidence of the aircraft’s approach.
LO design offered immediate tactical benefits by cutting
radar detection ranges and degrading the efficiency
of search radars. Signature reduction now posed substantial
problems for integrated air defenses (IADS) because it could
delay early warning detection and diminish the ability of fire
control radars to acquire and fire SAMs against the attacking
aircraft.
Aircraft Survivability and its Operational Impact
The payoff for low observables came from developing
an aircraft that could tackle each stage of the radar game.
Low observables offered a way to regain some of the surprise
element of air attack and improve the odds in each individual
engagement. Overall, LO aircraft would spend less
time in jeopardy from air defenses and stand a much better
chance of completing the mission and returning home.
The tactical benefits of increased aircraft survivability
opened up a wide range of options for air commanders.
Most important, spending less time in jeopardy could reduce
attrition rates by lowering the probability of aircraft being
detected, tracked, and engaged during their missions.
Highly survivable aircraft could be tasked to attack heavily
defended targets with much less risk. As a result, desired
effects—such as degrading enemy air defenses—could be
achieved in a shorter period of time. Critical targets that
might have taken repeated raids from large packages of
conventional aircraft could be destroyed in a single strike by
a much smaller number of F‑ 117s able to penetrate close
enough to use laser‑guided bombs (LGBs).
The final section of this essay quantifies the effects of
signature reduction in the tactical environment. Graphs
show how reduced signatures lower the time in jeopardy,
and how stealth degrades detection by early warning radar
and subsequent tracking and engagement by fire control
radars. Three hypothetical scenarios display the results of the
analysis in high and low threat environments. Variations for
altitude and attack profile are included. A short section also
discusses in general terms the potential synergy between
low observables and electronic countermeasures.
Since World War II, the radar game between attackers
and defenders has determined who will control the skies. The
winner of the radar game will be able to bring the maneuver
and firepower of air forces to bear against the enemy.
For the 21st century, highly survivable aircraft will contribute
directly to achieving joint force objectives. They will do this
by shaping and controlling the battlespace where joint air
and surface forces operate. The ability to project power with
efficient and effective air operations will depend on winning
the radar game.

 

[hunter1]

It would have been better if you could have just provided the source rather then copy pasting... just saying...

 

[Super Falcon]

i can't understand one bit what you are pasting

 

[monitor]

The Radar Game - Understanding Stealth and Aircraft Survivability

 

[nightcrawler]

it is a great concise book refereed to me by the Russian user namely ptdlm3 [weird name though!!]