Has anyone ever seen a UFO?

[theslug]

I've seen a red light in the sky that moved around all crazy like but it was most likely a super top secret flying vehicle from area 51. More importantly I was out camping once and I saw a nuclear weapons launch with my own eyes. Well it wasn't nuclear but it was definitely a rocket because it had a tail of smoke behind it. I wasn't exactly close either. But it was a freakin rocket!

[Gorth]

Yeah, the word "Aliens" could be interpreted in various ways.

Well, I did wonder at the very first if some fellow forumite felt bored and wanted to pull a prank, but he seems to be gone again. Maybe he got abducted?

[Dark_Raven]

The truth is out there.

[Guest The Architect]

Has anyone ever seen an Unidentified Fat Object?

[Bartimaeus]

I once heard a very strange mechanical flying noise above my house at night, two or three years ago. It wasn't moving, so it couldn't have been an airplane, and it sure as hell was no helicopter either.

 

One night, I was in bed, reading my book, and I heard some strange noise...it sounded like a giant mechanical machine moving its way across the city. It had a really strange sound when it moved, and I've never heard anything like it. And then, the second I look at the window, it stopped. I have absolutely no idea what it was, but none of my family members heard it, so who knows. Still, was very strange, and I went to bed right after incase I was getting hysterical or something, XD.

 

Aaannddd...my Grandma in Duluth, Minnesota, said she saw some strange flying object, (at first she said she thought it was child's toy), flying across the lake by her Mother's cabin, where she was staying at the moment. She said it was round, and was very weird looking.

[WILL THE ALMIGHTY]

They're coming on October 14th! The federation of Light!"

[Gorgon]

My dad told me he saw one on his way home from giving a lecture once. He was in a cab at the time, and the driver chased it around for an hour trying to get closer, eventually it just disappeared. Supposedly a disk shape, right out of the UFO myths.

 

Another person I know told me he had been visited by little green men at night, with a straight face and all.

 

I believe that they believed they saw an alien ship. Hippies have active imaginations, and there seems to have been a dramatic drop off in sightings from the next generation on.

Edited November 11, 2008 by Gorgon

[Slowtrain]

I read an article somewhere that discussed how in difficult econmic times reports of UFOs tend to rise. The article was talking about how when some people feel a lack of control over the events that are occuring around them, they will often "see" things such as UFO's.

[Slowtrain]

otoh: who really knows:

 

http://science.discovery.com/stories/week/...shoot-down.html

[taks]

there's a problem with the pilot's numbers...

 

since he was in an F86, i'm assuming his range radar was an AN/APG-30, which is an x-band, pulse doppler radar. x-band radars typically operate around 10 GHz (above 10.7 GHz is the Ku-band), so approximately 0.03 m wavelength. for a pulse doppler radar, there is a range/velocity equation that says

 

V_max * R_max = c * lambda / 8, where c is the speed of light (m/s) and lambda is the wavelength (m).

 

according to his numbers, V was as high as 7600 miles/hour, or 3398 m/s, and the closest range was 15 miles, or 24140 m.

 

for c = 2.9979e8 and lambda = 0.029979, V_max * R_max = 8.99e6 m^2/s, but his numbers result in V * R = 8.20e7 m^2/s, nearly a factor of 10 difference. either his velocity estimate is off by (at least) a factor of 10, or his distance is. ranging is pretty accurate with these radars, so i'm guessing the former. in other words, the target was really probably only moving 760 miles/hour, which is just barely supersonic. in reality, 15 miles was not the maximum range of the radar (farther), so the maximum speed was likely even lower than 760 miles/hour.

 

i did this pretty quickly so if anyone wants to check my numbers, please do...

 

taks

[Slowtrain]

7600 mph did seem extremely fast for an atmospheric ship of some sort. But I guess that's why they call them UFOs!

 

For comparison sake the fastest unmanned aircraft the x43 has a top of roughly 6500 mph.

 

And yes, I just looked that up.

Edited November 11, 2008 by CrashGirl

[taks]

my guess would be that he misread his radar returns, and/or there were some faulty images on his own screen. obviously there was something in the airspace otherwise he would not have been cued to respond to it, however his numbers clearly do not jive with real-world radar technology (it has nothing to do with current vs. past, btw, just physical limits of radar systems in general).

 

in short, his radar wouldn't be able to detect that speed, even if it was possible for some extraterrestrial (or even terrestrial) craft to achieve it.

 

taks

[Slowtrain]

WHat do you think about his size estimate? He said his contact was the size of an aircraft carrier or something. I mean, you don't see too many flying aircraft carriers, regardless of their top speed!

[taks]

WHat do you think about his size estimate? He said his contact was the size of an aircraft carrier or something. I mean, you don't see too many flying aircraft carriers, regardless of their top speed!

with this type of radar, it is impossible to tell how big the thing is (it's not a true SAR imager, just a positioner). he's basing his size estimate on the strength of the radar return, which could mean a lot of things. for one, it could mean the object was much closer than he originally thought, which would result in a larger return. it could also be the result of a false alarm, which would explain the erratic behavior. typically false alarms are due to noise and won't have coherence from one "image" to the next, so that is unlikely, but they can also result from simple electronic malfunctions or any of a number of interferences such as intentional jamming. hard to really say other than you can't tell from this type of return.

 

taks

 

* i put "image" in quotes because they are sort of images, but not pictures like something you could look at to determine size. what pulse doppler radars spit out are time-frequency matrices. one axis is time of arrival, which directly relates to distance, and the other is frequency, or doppler shift, which directly relates to speed.

[Slowtrain]

Would it be safe to assume though that a trained and experience pilot would be prepared for and aware of the potential for incorrect radar readings? Isn't it likely that upon encountering something as totally bizarre as this contact apparently was, his first thought would have been that his radar was malfunctioning in some way. I mean, if he was stationed in Britain at the height of the cold war, he was most likely not a total noob. lol.

[taks]

nope. trained, yes, but fully aware of all the nuances of pulse doppler radar, no way. given that this was in the late 50s, not only was radar relatively new (particularly this type), but counter-measures were as well. it was suggested at the bottom of the article that maybe there was some counter-measure being tested, and obviously if true, it worked well enough to fool the pilot (that would also explain why he never got a "response" regarding his inquiry...).

 

taks

[Slowtrain]

Also the F86d had an AN/APG 36, so as with most aircraft there was some variation on what electronics were in use at any given time. Don't know if that makes any difference, though.

[Slowtrain]

nope. trained, yes, but fully aware of all the nuances of pulse doppler radar, no way. given that this was in the late 50s, not only was radar relatively new (particularly this type), but counter-measures were as well. it was suggested at the bottom of the article that maybe there was some counter-measure being tested, and obviously if true, it worked well enough to fool the pilot (that would also explain why he never got a "response" regarding his inquiry...).

 

taks

 

lol. There goes my faith in the competence of fighter pilots. If they can't read their own radars they've got some problems.

 

ANway, thanks for the info. Interesting stuff.

[taks]

lol. There goes my faith in the competence of fighter pilots. If they can't read their own radars they've got some problems.

i don't think it is as bad as you might be led to believe. like i said, radar was fairly "young" at the time and there are a lot of nuances that can cause issues that won't normally show up. in general, a strong return means big target, particularly if you're seeing a long range target. but there are ways to "fool" radar, ways i'm sure they were either just first uncovering or at least experimenting with, many of which can't be conveyed to a pilot with limited knowledge of everything involved (i know because that's what i design). counter-measures as well as counter-counter-measures are still a big topic of research, btw, so it's not like all there is to know is known.

 

no problem, btw. radar is really cool, and i'm currently working on a variation of the pulse doppler concept that's even more cool than this one (IMHO, of course).

 

taks

[Walsingham]

I think taks deserves some kind of prize for cracking the maths on this. Behold the power of SCIIIIEEEEEENCE!

[samm]

The math isn't difficult (just look at the formula) - but knowing what applies to the kind of radar of this kind of aircraft is commendable

[Slowtrain]

taks is my radar hero. UFO Hunters should add him to their team.

[Gfted1]

Im surprised nobody brought those discrepencies (tagets speed / distance) to the pilots attention over all these years. I mean, it seems pretty cut and dry with the application of one formula.

[taks]

not commendable, nor outstanding, since i do radar for a living, but thanks anyway.

 

the first tipoff was the speed. here's a link that explains it all (i have books, but can't really point you to those as a link):

 

http://www.engineering.uiowa.edu/~ece195/2...ocs/Doppler.pdf

 

i think UFO hunters should simply think about things a bit before making wild claims. the reporter that wrote the piece was obviously not capable of discerning the validity of the pilot's statements. he was assuming (perhaps rightly) that the pilot really had a deep understanding of the general math behind radar. the pilots i work with that actually understand radar do so only at a cursory level, and mostly from a user perspective rather than an implementer perspective (they become contract managers after their flying days are over).

 

keep in mind, i'm guessing about the type of radar he was using. the AN/APG-30 was probably the most advanced technology they used on the F-86 sabre, so it seems to be a reasonable assumption that 7600 miles/hour was not within detection limits.

 

taks

[Walsingham]

I wonder how may more of our imponderables could be solved by getting taks to apply mathematics?