quellish said:It's likely that contact was lost, it flew until it ran out of gas, and glided to a rough landing in Iran. It may not have been operating over Iran at all, just pointed in that direction.
SOC said:What if it's covered in places (or someplace else on the jet is) with a mesh that appears solid from a distance or in a lower quality image, but is actually intended for air sampling? An air sampling platform would be far, FAR more valuable over Iran than any sort of traditional ISR platform.
UpForce said:No failsafes then?
UpForce said:I can only guess, but air sampling seems a good candidate; at least it was the first thing that came to my mind. The USAF has unique capabilities and decades of experience in the area of nuclear arms control flights (bespoke planes - can't remember type but large, passenger plane scale frames - and the Global Hawk was also deployed extensively at Fukushima) and the Homeland Security front also has some (purportedly) amazing sensors, picking up radiotherapy patients miles and miles away. Much information can be derived from minuscule amounts of isotopes, so why not have a moderately low observable thingy collecting samples pretty much routinely?
Eagle2009 said:Abraham/Quellish,
Except those kind of crashes still had a pilot at the controls did they not?
Ian33 said:The photo taken by Mr M Yon doesn't show this airframe. His photo clearly has different wing sensor array and also a series of what appear to be sensor windows along the right wing. This Iranian one does not.
quellish said:Because for air sampling, you don't fly OVER the target, you're flying wherever the wind is taking the output of the target. So if you're collecting on a target in Florida, you might be sampling in North Carolina, or Boston. The need for a VLO platform isn't really there, since you can usually find a way to sample in a permissive environment.
Jeffrey Richelson's "Spying On the Bomb" has several good accounts of air sampling missions.
http://books.google.com/books?ei=54riTvrVJ5TaiQL31ZTJBg&ct=result&id=gJcgAQAAIAAJ&dq=spying+on+the+bomb&q=sampling#search_anchor
blackstar said:That was air sampling of nuclear bomb blasts, when a huge amount of material is tossed into the atmosphere. That's not what the CIA would be looking for in this case. If they can do this with an aircraft, they would be seeking out much much smaller amounts of material, and trying to localize where it is coming from (i.e. secret manufacturing facilities) would be a major goal.
Ian33 said:The photo taken by Mr M Yon doesn't show this airframe. His photo clearly has different wing sensor array and also a series of what appear to be sensor windows along the right wing. This Iranian one does not.
What the Iranian variant is identical to in both color and rough finish is those photos that appeared in combat aircraft magazine. Could it be that the USAF have one variant and the CIA a smaller fleet of the earlier airframes? Bit like the CIA when they had the Predator fixed with Hellfires way way before the 'recce' variant became officially armed.
kcran567 said:This drone "should" be stealthier than a larger fighter.
kcran567 said:The only other option is it was a failed dead-end technology plant given to the Iranians, and that seems far fetched.
kcran567 said:The If this is legit it doesn't bode well considering the vast amount of money the West has spent on these systems. The west will collapse like the old soviet empire because we are spending ourselves into oblivion.
I think it was pointed out earlier that this platform was designed from the get go to be sacrificial. While there is some secret sauce in the hardware, the best secret sauce is in the software. If the software is loaded into volatile ram before each flight then the software goes poof when the power goes poof, and the power goes poof when the engine stops spinning.kcran567 said:If this is a legitimate detection/control/landing does this bode well for any of our stealth systems?
This drone "should" be stealthier than a larger fighter.
I doubt it was a visual detection, with some crazy Iranian in a white van getting a WiFi connection and landing it.
If this is legit it doesn't bode well considering the vast amount of money the West has spent on these systems. The west will collapse like the old soviet empire because we are spending ourselves into oblivion.
The only other option is it was a failed dead-end technology plant given to the Iranians, and that seems far fetched.
quellish said:kcran567 said:This drone "should" be stealthier than a larger fighter.
Why? RCS is independent of size.
bipa said:While I understand what you mean, this statement is slightly inaccurate at best. Size is one major factor that greatly "shapes" RCS of any object... just not in a monotonic way... and of course there are several other major factors.
bipa said:To take a guess at its RCS vs stealth fighters, we would need to see the underside of this beast. Please please Iranian soldiers: remove those camouflage nets, shoot more high-res pictures, and post back with a nice walkaround. ;-)
bipa said:No wonder: if the (supposedly skilled) LM ADP people went into the trouble of removing the tail, installing such an inlet blocker and taping all the joints, I trust them for not leaving fancy "Christmas balls" anywhere else, especially on the underside.
Apropos Christmas ornaments: has anybody already posted a theory about those two odd black strips (clearly visible on the right leading edge)?
bipa said:Regarding the circumstances of the crash/hijacking/landing: anybody knows what's the policy of US UAVs in the event of their datalink getting jammed? Loiter/climb and try to recover the link (until it runs out of fuel)? Return to base?
Abraham Gubler said:kcran567 said:The only other option is it was a failed dead-end technology plant given to the Iranians, and that seems far fetched.
Iranians hack the drone or an intentional white ant operation? They are your only two options? Ever heard of aircraft having problems and crashing? If not may I suggest you catch up on a few episodes of Air Crash Investigation.
http://natgeotv.com/uk/air-crash-investigation
kcran567 said:The If this is legit it doesn't bode well considering the vast amount of money the West has spent on these systems. The west will collapse like the old soviet empire because we are spending ourselves into oblivion.
UAV crashes in Iranian desert equals the end of the western countries? While the EU and USA (which is not ALL of the west) may in some ways resemble the financial troubles of the Soviet Union the difference is still several significant figures. The ‘west’ is having trouble with cash flows and over imaginative medias feeding the fears of ignorant fools. The Soviet Union suffered a complete societal, political, technological and economic collapse. Saying they are the same is like saying a toy boat a baby plays with in the bath is the same as MS Oasis of the Seas.
quellish said:bipa said:Size is one major factor that greatly "shapes" RCS of any object... just not in a monotonic way... and of course there are several other major factors.
No, RCS is really independent of size.
http://books.google.com/books?id=0WuGjb8sqCUC&lpg=PP1&dq=radar%20cross%20section&pg=PA294#v=onepage&q=size&f=false
"Thus, the radar cross section of those shapes is not dependant on their size, and large versions of such shapes have the same RCS as small ones"
Size matters as it affects shaping for the relevant frequencies, but the size of an object has no correlation to its RCS.
quellish said:This: http://en.wikipedia.org/wiki/ADM-20_Quail
Has the same RCS as: http://en.wikipedia.org/wiki/B-52_Stratofortress
quellish said:Why take a guess when there is enough information out there now to model it?
quellish said:bipa said:two odd black strips (clearly visible on the right leading edge)
Higher resolution photos of the vehicle in Iranian hands clearly shows where it was taped together for show, as well as scratches, stains, etc. along the underside indicating a wheels up landing.
RCS is really independent of size.
Stargazer2006 said:RCS is really independent of size.
I would imagine so... But still, I wonder: if a B-2 has the RCS of a bird, would a B-2 shaped, bird-sized R/C model have the RCS of a fly? Or keep that of a bird? I'm not so sure that RCS reduction is that effective in smaller scales. Any thoughts?
kcran567 said:If this is a legitimate detection/control/landing does this bode well for any of our stealth systems?
bipa said:Bottom line: given all these assumptions, you may end up closer to the RCS of a fly (but only at the upscaled frequency).
bipa said:Fine... If it makes you feel wiser to take a random sentence out of Knott (relating to a theoretical reasoning about specific shapes under specific illumination conditions) and reformulate it as a general truth... I'm not going to beat a dead horse on this most trivial topic, but just in case you didn't catch my first post: I agree with you, though, that this drone "should" not necessarily be stealthier than larger fighters (at least not just because of its smaller size, as kcran567 seemed to imply).
bipa said:Given adequately sized radar reflectors ;-)... and better with a little help from an active radar repeater...
bipa said:Have any decent picture of the underside then?
Or is the RCS of any object also uncorrelated to its underside? (Knott citation needed ;-) )
quellish said:That's what I first thought, but on the very same high-res pictures those strips really don't look at all like duct tape to me, and there is something either side of them that looks like a mechanical interface blended into the airframe.
Eagle2009 said:Thoughts?
XB-70 Guy said:If you look very closely at the leading-edges of the B-2's wings - lol, you'll see minute curvatures as on it's trailing edges. - SP
Eagle2009 said:I recently ran into something interesting on Wikipedia's page of the RQ-170, namely in the Discussion section. IN said section, an author makes the argument that one of the stated dimensions for the Sentinel is WAY off, while the other two are fairly accurate. He/she did so by imagery analysis and I think they make an interesting argument.
quellish said:bipa said:Bottom line: given all these assumptions, you may end up closer to the RCS of a fly (but only at the upscaled frequency).
No, you would have the same RCS as the original object. This is how pole testing scale models works.
... or not (sigh).quellish said:RCS is really independent of size.
quellish said:There is visible peeling of the tape in several areas, and it covers clearly defined cracks and seams. If you were to measure the tape in the photos, you might find that the width is exactly the same as commonly available duct tape or gaffer's tape.
quellish said:No, you would have the same RCS as the original object. This is how pole testing scale models works.
bipa said:Keep in mind that RCS behaviour is highly dependent on the size / wavelength ratio. If you were able to downscale everything (including some very tiny details, as well as material properties, which is generally impossible), it would have exactly the same dimensionless RCS pattern shape at the downscaled wavelength (or, in other words, upscaled frequency, which won't lie in the same radar band). However, its absolute RCS magnitude (in square meters) would be lowered according to the square of your scale factor.
bipa said:We are not talking about the same thing: I have seen this tape, but it lies further along the wing. I was referring to the short black strips, kindof shiny, on the right leading edge. There is no peeling and no sign of crack or seam. They seem to be built into the platform somehow. Maybe some kind of binocular sensor?
Arguably that looks more like it echoes what bipa said - your comment did not make any mention of the requirement to scale.quellish said:I'm not sure where the confusion is coming from. The very page you are linking to echos what I said:
http://books.google.com/books?id=0WuGjb8sqCUC&lpg=PP1&dq=radar%20cross%20section&pg=PA257#v=onepage
from Knott, Shaeffer, Tuley.
My post:
quellish said:No, you would have the same RCS as the original object. This is how pole testing scale models works.
Well, if you were agreeing with what bipa said there, responding with what amounts to "No, you're wrong" when taken at face value seems like a patently unhelpful way of expressing your agreement.quellish said:In response to the earier post:
bipa said:Keep in mind that RCS behaviour is highly dependent on the size / wavelength ratio. If you were able to downscale everything (including some very tiny details, as well as material properties, which is generally impossible), it would have exactly the same dimensionless RCS pattern shape at the downscaled wavelength (or, in other words, upscaled frequency, which won't lie in the same radar band). However, its absolute RCS magnitude (in square meters) would be lowered according to the square of your scale factor.
Knott's "Radar Cross Section Measurement" has a chapter on scaling laws, as applied to measuring scale models as RCS targets. For example, if you are testing a 1/48 scale model the test frequency must be 48 times the "real world" frequence (i.e. if you designed for a 1GHz radar, you test with a 48GHz radar on your 1/48 model). To take the result of that scaled testing and apply it to your real world vehicle, multiply the test result by the square of the scaling factor (i.e. 48^2).
If I am not mistaken, this is what was being described in the above post.