I suggest everyone read this article first.
It shows the strengths and weaknesses of stealth from both the attackers and the defenders.
Here is an excerpt
Counters to Stealth
Because stealth is so important to current air
operations and military strategy, it is reasonable
to ask if and when it might be effectively
countered. Historians contend that every military
invention in history has been countered by new
inventions or tactics, in due time. The radar game
illustrates this principle, too. Radar changed the
survivability duel during the Battle of Britain in
1940. Stealth changed it back fifty years later, in
the Persian Gulf War of 1991. The most relevant
question to ask is not “can stealth be countered?”
but “how difficult is it to counter stealth with
known technology?”
The radar range equation that demonstrates how
lower RCS reduces the range of detection contains
several variables. To counter stealth with a monostatic
radar, the air defense radar would have to
greatly increase its gain at the receiver. The way to
do this would be to greatly increase the power of
the system. If the target aircraft had an RCS reduction
of 1,000 the radar power would have to
increase by a factor of 1,000 to detect it at the same
range as a non-stealthy aircraft. However, increasing
power is easier at long wavelengths, not at the
short, rapid frequencies commonly used for fire
control. Ultra-wide band radar poses a similar
problem. An ultra-wide band pulse could emit
waves at several different frequencies hoping to
catch the stealth aircraft at a weak point in its
RCS reduction. But transmitting over a wide band
diminishes the power in each band, cutting the
efficiency of the radar.
The second issue in discussions of counter-stealth
is that stealth aircraft are designed against monostatic
radars, the type used in nearly all military systems.
Monostatic radar couples the transmitter and
receiver at the same place, a process that simplifies
the crucial function of distance tracking. In theory,
a bistatic radar that placed the transmitter in one
location and the receiver in another might be able
to pick up what might be called the “trailing” RCS
that is directed away from the monostatic radar.
However, “bistatic radars, while simple in concept,
have many fundamental technical and operational
issues to overcome,” according to John
Shaeffer, radar cross section engineer at Marietta
Scientific in Georgia. The receiver antenna beam
must intercept its companion transmit beam, and
follow the transmit pulse which is moving at the
speed of light. Unless the transmitter and receiver
pulses are synchronized, distance measurement is
impossible. Even a workable bistatic radar must
then address the problem of how much volume of
airspace it can scan at a given power setting in a
given time. When the receiver, transmitter and target
are located on a straight line, the receiver can be
overwhelmed by the transmitter pulse, which hides
the target’s radar return. As Shaeffer put it, “this is
similar to looking into the sun for light scattered
from Venus.”1
The RCS reduction of stealth aircraft is difficult
to counter. Improvements in radar must go a very
long way to match the performance they were
designed to achieve against non-stealthy aircraft.
Concerns about countering stealth should pale in
comparison to those about the known and increasing
threats to conventional aircraft. The day will
probably come when reusable hypersonic military
spaceplanes replace jets as the primary vehicles
for ensuring aerospace dominance. Until then,
for as long as jet aircraft offer the most reliable
option for air superiority and air attack, stealth
will be indispensable.
