Originally posted by Aim64C
You have to remember that, essentially, the F-22 is 20 years old. Radars from 20 years ago are functionally similar, but the filtering capabilities
are all together different.
Actually, the big part of stealth that I like to get at is its effectiveness at decreasing the range at which a usable return can be found. The
largest part of this could be viewed as reducing the amount of radar waves that actually make it back to the receiver on the aggressive a/c (with
geometry and RAM to absorb or redirect the waves) rather than trying to convince the enemy radar into overlooking the bogey (jamming techniques and
datalink camouflage), since you correctly pointed out that the algorithms and processing power to weed out the nonsense and pluck out the target have
progressed far over the times.
This is, of course, not to downplay the progress of radar power or jamming techniques. But as you've stated, filtering capabilities
are
altogether different, rather compromising the effects of the jamming, powerful though it may be. If the jamming is there to be detected (as large
masses of static may be), there are functions like the touted "Home on Jam" that can cause problems anyway. You've also stated that the radars work
on similar principles, and it occurs to me that even modern radars need a signal return to be of any real use. It would seem, then, that geometry and
RAM techniques to spoil the radar return and diminish the distances at which the a/c can be detected are a little more effective than jamming
techniques to disguise the return in a world where BVR missiles grow far deadlier than their shorter-range (and more stylish
) IR cousins.
I'm sorry I didn't make that clear enough in the post. I just kind of wanted to break up the discussion about the overall effectiveness of stealth
by either logic or by producing another target
.
At this point, geometry of the aircraft begins to play a more significant role in the return signature than the material it is made of or the surface
area exposed. Remember that a property of all moving magnetic fields (radios, radar, magnets, etc) is that they induce an electric current in all
conducting materials that is 180 degrees out-of-phase with the source. That means... guess what... your plane becomes a giant antenna - so do all
structures inside of it (assuming they are not shielded against EMF). That means stealth technology goes well beyond the skin of the aircraft, and
goes to the internal structure, the way the internal components are shielded, etc. You could build an aircraft out of composite materials and have a
larger RCS than a similar aircraft that had an aluminum or titanium-based airframe.
A couple questions based on my rudimentary knowledge of the physics behind radio waves and antennae:
-Are radio waves moving magnetic fields (The whole EM radiation thing is not quite settled in my brain yet, so I'm not sure if it could be called a
field or not as it's been explained to me as a radiation wave)?
-If it can be counted as a magnetic field, I understand that it can induce an electric current
a la antennae, but wouldn't the receiving
structure need to be the proper length so as to match up the resonating frequency with that of the incoming wave? What is the likelihood of that?
-If the electric field is, in fact, created, would it also result in further radiation being projected from the hybrid antenna-aircraft to be detected
by the original radar-projecting a/c?
If the answer to all these non-rhetorical questions is actually "yes", then I'm good with that. But, that's also a part of structure
considerations for an aircraft, so keeping those factors in mind like they did when designing the LO frame of the F-22 should be a priority. At least,
I should say, IIRC they considered it. Could be wrong, though, it wouldn't be a first.
The U.S. made their investment in stealth technology based on two main ideas - first, that radars would always have to filter out small radar returns,
and second that control of digital processing components would be assured to contain the spread of the necessary capability for radars that could
endanger stealth aircraft.
While at medium ranges, you're absolutely right, the radars would be able to detect the F-22, isn't the long-range fight the more (and I loath this
word, believe me) important to consider? One main ideal across these boards is that controlling the information in the battlespace is essential to
victory. At 100km or so, it would be reasonable to expect that both sides have decent fixes on enemy locations with radar and whatnot. But if you know
where the enemy is prior to or at the commencement of combat, say, 50km before they know where you are (since detection at long range is already a bit
tough and stealth decreases the usable return to recognize a bogey), it would seem to give an advantage.
I know this doesn't seem directly applicable to the quote just above, but I'm trying to comment on the concept of smaller returns. Within radar
range, if you have even a small (but consistent) return, you can get usable information since the only things capable of doing Mach 2 are enemy jets
or those crazy super-insects that humans are probably making with bioengineering and whatnot. At really long ranges when the huge distances across
which BVR missiles travel, however, the faster you can detect an enemy, the better off you'll be. And if stealth can decrease the probability of a
bogey finding you before you find them, it seems like a good investment into what was intended to be the supreme commander of the air.
However, it means the face of "Stealth" must change. Radar, while being an important concern, is no longer the primary concern. Modern jamming,
countermeasures, and passive reduction ("Stealth") technologies essentially ensure that any two aircraft will have to close to a "merger" before
being able to score a kill.
Hmm... I had thought we just finished discussing how radar recognition and processing power had progressed to the point where it became possible to
pick out the details showing that an aircraft is present in the swath of garbage present in the atmosphere with or without jamming involved? Sorry if
I'm misunderstanding, here, it wouldn't be surprising of me to misinterpret what you were arguing for/against.
Optical and Infra-Red reduction methods are where the future of "Stealth" is.
Optical stealth I can see since image capture and display technologies are miniaturizing quickly with new materials and concepts, but IR stealth
confuses me a bit. How does one expect to disguise the massive jet plume and heat signatures caused by engines that run simply by adding warmth to air
for propulsion? I can see disguising it by cooling it down with outside air, but I'm not sure how you could achieve "disappearing from the face of
the Earth" style results as has been performed with radar signatures by aircraft like the B-2 Spirit (whose stealth was unparalleled upon its release
into the wild)? It just seems, to me, to be a pretty tall order to try to conceal such a large signature output since the main function of parts of
the aircraft necessitate creating the heat and then releasing it.
But, that's my rant for the day. Have a good one.
