ar73+@andrew.cmu.edu (Aymerik Renard) (01/21/91)
From: Aymerik Renard <ar73+@andrew.cmu.edu> >From: wade@gouda.ucs.ubc.ca (Doug Wade) > >Our local newspaper reported that B-2 stealth bombers were in the >Persian Gulf. Am I right in assuming they err'ed and really meant >the F-117? The B-2 is the stealth bomber. The F-117A is the stealth fighter. It's also interesting to note that the F-117A can be detected by radars on some of the Mirage planes. -Aymerik Renard ar73@andrew.cmu.edu Carnegie Institute of Technology Carnegie Mellon University
gwh%soda.Berkeley.EDU@ucbvax.Berkeley.EDU (George William Herbert) (01/23/91)
From: gwh%soda.Berkeley.EDU@ucbvax.Berkeley.EDU (George William Herbert) In article <1991Jan21.041430.5413@cbnews.att.com> ar73+@andrew.cmu.edu (Aymerik Renard) writes: > The B-2 is the stealth bomber. The F-117A is the stealth fighter. >It's also interesting to note that the F-117A can be detected by radars >on some of the Mirage planes. Do you have a source on that? >From my understanding of it, it's stealthy in 2 ways: one, it's flat surfaces have a near-zero radar return at any frequency (except at radar wavelength approaching the plane's size...) unless viewed directly perpendicularly. The second way is that those flat plates are also covered with Radar Absorbent Material of various types and thicknesses, that reduces the return from a flat-plate perpendicular return to less than a normal aircraft would return anyway. I've read a lot of sources and not seen anything that indicated that it was radar-visible at any frequency below long-wavelength radars. I welcome a correction, but i'd like to see the source on the info. 8-) == George William Herbert == * UNIX ate my last .sig, Waiting for Plan 9! * == JOAT for Hire: Anything, == ######### I do Naval Architecture, ########## ===+++ Anywhere, my price +++=== # Spacecraft Design, UNIX Systems Consulting # == gwh@soda.berkeley.edu == # RPG writing/development, and lots of other # == gwh@ocf.berkeley.edu == ## random stuff, of course. I'm a JOAT 8-) ##
dold@mitisft.Convergent.COM (Clarence Dold) (01/24/91)
From: dold@mitisft.Convergent.COM (Clarence Dold) in article <1991Jan23.044226.7926@cbnews.att.com>, gwh%soda.Berkeley.EDU@ucbvax.Berkeley.EDU (George William Herbert) says: >From my understanding of it, it's stealthy in 2 ways: one, it's flat surfaces > have a near-zero radar return at any frequency (except at radar wavelength > approaching the plane's size...) unless viewed directly perpendicularly. The Long ago, I worked on a low frequency radar. SR-71 would overfly our radar coverage area, and we could actually see them quite well, although they were 'stealthy' to the higher frequency radar used by flight line control towers. Typically, SR-71 would 'announce' their incoming position, both by voice, and an occasional IFF squawk. They could often be spotted with binoculars before they showed clearly on radar. This was on the tower radar units, which didn't carry the cute little ID displays that todays displays have. On our displays, the SR-71 was clearly visible, but not for long ;-). -- --- Clarence A Dold - dold@tsmiti.Convergent.COM (408) 435-5293 ...pyramid!ctnews!tsmiti!dold FAX (408) 435-3105 P.O.Box 6685, San Jose, CA 95150-6685 MS#10-007
orpheus@reed.UUCP (P. Hawthorne) (01/24/91)
From: orpheus@reed.UUCP (P. Hawthorne)
Aymerik Renard writes:
. The B-2 is the stealth bomber. The F-117A is the stealth fighter.
. It's also interesting to note that the F-117A can be detected by radars
. on some of the Mirage planes.
What are your sources? Are they assuming that the Mirage intercepts
the Nighthawk at a perpendicular flight path with doppler shift radar?
Or maybe just a game of chicken?
The stealth is not perfect, and depends on quite a few factors such
as the angle to the radar and the type of radar being used. Still, the
plane is as stealthy as was possible when the design was completed in 1983,
if I remember the press release correctly.
orpheus@reedswilliam@dtoa1.dt.navy.mil (Williams) (01/24/91)
From: swilliam@dtoa1.dt.navy.mil (Williams)
> ... The F-117A is the stealth fighter.
Wouldn't it be strange that a fighter is designed with a internal bomb
bay big enough to carry two 2,000 lb bombs? It sounds like the F-117A
is more like a fighter/attack plane like a F-15E Strike Eagle is, only
that F-15E doesn't have an internal bomb bay.smpod@venus.lerc.nasa.gov (Stefan) (01/25/91)
From: smpod@venus.lerc.nasa.gov (Stefan) In article <1991Jan21.041430.5413@cbnews.att.com>, ar73+@andrew.cmu.edu (Aymerik Renard) writes... > The B-2 is the stealth bomber. The F-117A is the stealth fighter. >It's also interesting to note that the F-117A can be detected by radars >on some of the Mirage planes. Many radars can detect the stealth aircraft when they're close enough. The question is 'can they detect them in time to counter?'
biocca@bevsun.bev.lbl.gov (Alan Biocca) (02/04/91)
From: biocca@bevsun.bev.lbl.gov (Alan Biocca) In article <1991Jan24.045047.27085@cbnews.att.com> swilliam@dtoa1.dt.navy.mil (Williams) writes: >From: swilliam@dtoa1.dt.navy.mil (Williams) >> ... The F-117A is the stealth fighter. >Wouldn't it be strange that a fighter is designed with a internal bomb >bay big enough to carry two 2,000 lb bombs? It sounds like the F-117A >is more like a fighter/attack plane like a F-15E Strike Eagle is, only >that F-15E doesn't have an internal bomb bay. The Stealth design requires that weapons be mounted internally to avoid radar detection of the weapons. One computer game based on the 117 has bays for all missiles and bombs. They claim the majority of the radar reflection from the aircraft head-on is from the pilot's seat back, since the exterior surfaces reflect the radar off in other directions rather than back at the source. I don't know how accurate these game designers are, but they usually get pretty good info. Alan K Biocca WB6ZQZ
wcarroll@encore.encore.com (William Carroll) (02/08/91)
From: jake!wcarroll@encore.encore.com (William Carroll) biocca@bevsun.bev.lbl.gov (Alan Biocca) writes: > > They claim the majority of the radar > reflection from the aircraft head-on is from the pilot's seat back, since > the exterior surfaces reflect the radar off in other directions rather > than back at the source. I recall a note in the AvLeak article on the F-177A rollout that said that the cockpit glass had a special coating to prevent radar from penetrating. Otherwise the pilot's helmet would generate a larger radar return than the rest of the plane. I don't know whether it is true or not, but just the statement impressed me. -- William R. Carroll (Encore Computer Corp., Ft. Lauderdale FL) wcarroll@encore.com uunet!gould!wcarroll "This comment without commentary is not the view of the staff or management of WKPX, the Broward County School Board, ... or even me." - KZ
brndlfly@athena.mit.edu (Matthew T Velazquez) (02/09/91)
From: brndlfly@athena.mit.edu (Matthew T Velazquez) Yes, F-117A canopies are coated with a very thin gold film (inside? outside? somewhere in between?) to prevent the helmet from broadcasting a radar signature. If you look at a picture taken from an oblique angle, you can see this film reflecting sunlight. That's also from Jay Miller's Aerofax Extra on the F-117. T Velazquez MIT Aero/Astro brndlfly@athena.mit.edu
v134hhhy@ubvmsb.cc.buffalo.edu (Matthew J Kolokowsky) (02/09/91)
From: v134hhhy@ubvmsb.cc.buffalo.edu (Matthew J Kolokowsky) In article <1991Feb8.021032.20818@cbnews.att.com>, jake!wcarroll@encore.encore.com (William Carroll) writes... >I recall a note in the AvLeak article on the F-177A rollout that said that >the cockpit glass had a special coating to prevent radar from penetrating. >Otherwise the pilot's helmet would generate a larger radar return than >the rest of the plane. I don't know whether it is true or not, but just >the statement impressed me. > The F-177A has an radar APPARENT cross section of .6 square meters, about 5.4 feet (compared to 170ish for a B-52, and around 3 square meters was it for a B-1?). A person's head has a cross-section of in the realm of .08 square meters. Pilot's seat would send back a bigger signal than the rest o' the plane. . . Does anyone know how the infra-red sighting on the F-117 works? ie: Is it only forward facing?, is it movable?, does it have zoom capability? Matt =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= A squid eatting dough in a polyethylene bag is fast and bulbous. Got me?