[HN Gopher] Finding the B-21's hanger location from the stars in...
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Finding the B-21's hanger location from the stars in its press
image
Author : johnmcelhone
Score : 278 points
Date : 2022-12-08 19:53 UTC (3 hours ago)
(HTM) web link (twitter.com)
(TXT) w3m dump (twitter.com)
| sp332 wrote:
| *Hangar
| rob74 wrote:
| It's "hangar", not "hanger", dammit!
| saraton1n wrote:
| This reminds me of the Elon plane tracking dude. Such a neat use
| of technology and know-how.
| darknavi wrote:
| Note to self: Always, always, ALWAYS strip exif data.
| lortrq wrote:
| I would like to know what else is embedded in digital pictures,
| similar to the printer yellow dots, except it will be
| undetectable.
| colechristensen wrote:
| Sensor noise has been used to successfully identify the
| camera used to take a picture. No embedded features just the
| physical characteristics of sensors being individual enough
| to identify.
| Kiboneu wrote:
| You've confused the data with the metadata.
| riffic wrote:
| metadata is actually a form of data, believe it or not.
| pjot wrote:
| The data's data!
| quickthrower2 wrote:
| Metadata is data, but without legs
| bfgoodrich wrote:
| a1369209993 wrote:
| I assumed that was the joke? If they're finding the location
| based on the stars in the image, you'd need to strip out the
| actual image data (not matadata) to prevent that.
| Denvercoder9 wrote:
| Exif data is the metadata of the image.
| lmm wrote:
| Exactly, whereas stars shown in the image are just data,
| you don't need the exif data to see them.
| insane_dreamer wrote:
| But the time the photo was taken was extracted from the
| exif which is what OP was referring to stripping
| nomel wrote:
| Couldn't the same conclusion be reached, without? That plane
| flying overhead, center, would probably make things much
| easier.
| NikolaNovak wrote:
| Related unrelated question : how come this is public?
|
| F117 was a dark skunk project shown years after being
| operational. That made sense to me for a super secret project
| with wildly new technologies and capabilities.
|
| I don't understand the announcements of such projects from the
| vision stage, with the details of capability, purpose, strategy,
| photos,etc.
|
| Is it commoditized sufficiently? Is it deterrence? Is there
| enough misinformation?
| dragonwriter wrote:
| > Related unrelated question : how come this is public?
|
| Because trying to hide the existence of strategic bombers is
| expensive, ineffective, and not particularly helpful to keeping
| the actually secret technology they use secret.
|
| > F117 was a dark skunk project shown years after being
| operational
|
| With the F-117, the shape was part of the secret sauce. The
| B-21 doesn't seem to be a big departure that way.
|
| > I don't understand the announcements of such projects from
| the vision stage,
|
| This wasn't announced in the vision stage, except that a new
| strategic bomber was being developed. The unveiling was well
| past vision, and competition, stages.
|
| > Is it commoditized sufficiently? Is it deterrence? Is there
| enough misinformation?
|
| Deterrence is a big consideration,
| jasonwatkinspdx wrote:
| > With the F-117, the shape was part of the secret sauce. The
| B-21 doesn't seem to be a big departure that way.
|
| The world has also changed substantially. When the F-117 was
| developed, being able to simulate the RF interactions with
| faceted geometry was ground breaking stuff. Now anyone that
| can afford an ANSYS license can simulate that with far, far,
| greater fidelity against much more complex shapes.
| [deleted]
| dotnet00 wrote:
| There's of course the slightly conspiratorial idea that they
| made this public because it's obsolete compared to whatever
| their newest toys are and so revealing this as a show of
| technological superiority is fine.
| [deleted]
| ForHackernews wrote:
| I've read some things that suggest the B-21 may not offer
| radical new capabilities (over say, the B-2) but it will be way
| way cheaper to build and operate.
|
| There were only 21 B-2s ever built. The Air Force has already
| ordered 100 B-21s.
| kevin_thibedeau wrote:
| That number will shrink. There were supposed to be 100+ B2s
| and no B1Bs.
| dragonwriter wrote:
| > There were only 21 B-2s ever built. The Air Force has
| already ordered 100 B-21s.
|
| Planned, not ordered. Just like they initially planned 130+
| B-2s, which Congress eventually cut to 21.
| influx wrote:
| Kirk: Bones, did you ever hear of a doomsday machine?
| McCoy: No. I'm a doctor, not a mechanic. Kirk: It's
| a weapon built primarily as a bluff. It's never meant to be
| used. So strong, it could destroy both sides in a war.
| Something like the old H-Bomb was supposed to be. That's
| what I think this is. A doomsday machine that somebody used in
| a war uncounted years ago. They don't exist anymore, but
| the machine is still destroying. -- Star Trek: The
| Original Series, "The Doomsday Machine" Dr.
| Strangelove: Of course, the whole point of a Doomsday Machine
| is lost, if you keep it a secret! Why didn't you tell
| the world, eh?!! Russian Ambassador Sadesky: It was
| to be announced at the Party Congress on Monday. As you
| know, the Premier loves surprises. -- Dr.
| Strangelove
| Rebelgecko wrote:
| The secretary of defense mentioned "deterrence" as part of the
| reasoning. Maybe not-so-coincidentally, the aircraft (at least
| as they showed it) skips the old school black paint job for one
| that looks more like anti-flash white[0].
|
| Part of it is probably also that this is a refinement of an
| existing aircraft and not anything with drastically different
| capabilities-- if you're planning on war with the US, you're
| probably already thinking about B-2s, and if you're worried
| about B-2s then a B-21 isn't _that_ different.
|
| [0]: https://en.wikipedia.org/wiki/Anti-flash_white
| chasd00 wrote:
| it may be its operational capabilities are more important to
| keep secret. It has an unmanned mode which is very interesting
| to me. Does it need to be piloted by a guy in an office cube
| like the Predator drone or is it more autonomous?
| dragonwriter wrote:
| > It has an unmanned mode
|
| Maybe. "Designed to accommodate unmannef operations" is...
| fairly vague as a description.
| mgarfias wrote:
| I mean, cool and all. But I didnt have to do that to know where
| it was. I stood outside that hanger (with a B-2 inside) in 1989
| at Northrop's 50th anniversary airshow.
|
| If I can remember that, from 30+ years ago, I'm pretty sure the
| russians/chinese/whateverese also know.
| pifm_guy wrote:
| It's worth noting that stars can be seen even in daylight with
| the right software.
|
| That's because, while no individual star is visible, the exact
| angles between all stars is fixed, so you can do a brute force
| search of all possible orientations of the sky to find a matching
| one. In a 6 megapixel image of half blue sky, you effectively get
| an oversampling ratio of 3 million:1, so even with very bright
| sunlight obscuring the stars to the naked eye, your algorithm
| will pick them out.
| skykooler wrote:
| How long does this take? Could this be run on, say, a
| smartphone to calculate its rough position from a photo of the
| sky?
| folli wrote:
| Very interesting! Any links for further reading?
| pifm_guy wrote:
| Nope - years ago I accidentally discovered this while trying
| to align star images for stacking. Some of my images were
| taken in daylight, and I was surprised to find my rudimentary
| image aligner still worked just fine. Never wrote it up into
| a blog post.
| 4gotunameagain wrote:
| Do you mind expanding a bit more ? Because I don't
| understand. Even if you have oversampling, as you say, it
| would be after you know the locations of the stars, and
| also, how can you brute force every possible right
| ascension/declination/rotation ? Without a calibrated
| camera how do you account for the distortions ? Thanks
| pifm_guy wrote:
| In my case, I had nighttime images from the same camera,
| so all the calibration was already done... I was just
| looking for a rotated version of the nighttime image in
| the daytime image.
|
| But even in the general case, smallish image patches
| don't have enough distortion to matter, while still
| having plenty of oversampling, and only have 3 unknowns.
| You can probably do some kind of fft trickery to reduce
| it to 1 unknown. And you can probably use some kind of
| hill-climbing to further reduce the search effort.
| 4gotunameagain wrote:
| What does an optimization algorithm have to do with a
| brute force search?
|
| Even if your image patch is small, without previous
| images to compare, you need to brute force the entire
| sky?
|
| And how can "fft trickery" reduce the attitude state to 1
| unknown ? 1 unknown with what units ?
|
| Sorry but I suspect you are making all these up.
| dekhn wrote:
| I don't understand what they are saying but it's
| definitely true if you are careful, you can take images
| of the locations of the top magnitude stars, point your
| camera at that, take a long exposure (~15 seconds, so you
| need a way to keep the moving star at exactly the same
| pixel over the whole exposure), do some contrast scaling,
| and you will see point pixels lit up in the right
| locations.
|
| If you don't already know a star location, I'm sure you
| could construct a very sensitive camera and some noise
| reduction and do this with short exposures without any
| rotation.
| boardwaalk wrote:
| I mean, they livestreamed the rollout on YouTube on the Edward's
| AFB YouTube channel and said it was at NG's Palmdale facility
| (paraphrasing). I'm not sure any of this was a secret...
| bri3d wrote:
| This is acknowledged by the author:
| https://twitter.com/johnmcelhone8/status/1600683636029652993
|
| Which I think is also why the thread is so X-marks-the-spot /
| parallel-reconstruction-y. I think it's more of a "here's the
| kind of thing we can do with these star-matching tools, applied
| to an interesting image as an example" than an expose.
| bee_rider wrote:
| Also the Airforce and Northrop Grumman must be familiar with
| the idea of celestial navigation. And the shot was clearly
| taken in the evening on purpose (I assume, at least, that a PR
| shot has to justify being taken outside of maximum daylight).
|
| They probably want it to feel vaguely spacey for the sci-fi
| vibes.
|
| They've got at least as good star charts as the rest of us, so
| if they really wanted to be jokers they could photoshop some
| stars in, make it look like it is flying over an adversary's
| country...
| avalys wrote:
| Not only that, they had three bombers (B1, B2, and B52) fly
| over during the live stream of the unveiling that could be
| tracked live on commercial flight tracking websites. This
| simply wasn't a secret at all.
| 4gotunameagain wrote:
| This livestream is the best caricature of American culture
| I've seen, thank you.
|
| It is the unveiling of a bomber, with the national anthem
| sung by an employee of the company who built it, as in a
| proper performance, while more bombers fly ahead so loudly he
| has to stop. Then it proceeds to have the CEO read an
| engineered speech from a teleprompter, completely devoid of
| her own existence. Followed by a hollywood action movie style
| reveal, with the attendees going wild, clapping and shouting
| for the new, shiny bomber. It is a gift that keeps on giving.
|
| https://www.youtube.com/watch?v=chJlJgrvfBY
| rootusrootus wrote:
| With the casual change from "34-35 degrees" to "lets draw a line
| at 34 degrees" followed by the "and this is where the press
| release was" I got the vibe that this was parallel construction.
| Still some good sleuthing, don't get me wrong, but still.
| dsfyu404ed wrote:
| Also goes to show you the danger of tunnel vision.
|
| If they flew one to some air base outside DC for the roll out
| the author would be shooting from the hip and who knows what
| facility he'd have zero'd in on. Sure it might have been the
| same one because "the same facility as the B2" is an easy just-
| so story but you don't really know with any certainty.
| johnmcelhone wrote:
| You're right, it wasn't too difficult to guess the location
| without the stars. The base did happen to be right in-between
| the 34 and 35 degree lines (34.6 lat), and you can estimate
| pretty well with only one line
| cossatot wrote:
| Little Rock AFB is a few tens of km north (34.9 deg lat) for
| what it's worth. There may be some others as well. The
| chances of getting a picture of the stars that clear in
| Arkansas is way lower than in the Mojave however...
| lilyball wrote:
| "let's draw a line at 34 degrees" makes for a nice display, but
| presumably the actual filtering for matching bases spanned
| 34-35 degrees.
| lambdasquirrel wrote:
| I don't know if I entirely buy the line on "34-35 degrees off
| the horizon." Unless we knew the focal length of the lens it
| was taken with, and which camera it was taken from, you don't
| actually know that. A wide-angle lens is going to have a much
| larger field of view than, say, a 100mm macro. And different
| camera systems have different angle of view for the same focal
| length.
| 4gotunameagain wrote:
| both the focal length and the field of view are irrelevant,
| you know the angles between the stars so you can infer
| everything.
| vilhelm_s wrote:
| You know what the angle between the stars in the
| constellation are, you don't need to know the field of view
| of the camera.
| johnmcelhone wrote:
| You don't actually need the focal length, it doesn't help
| accuracy that much but can help you line up the sky to the
| photo a bit quicker. Anyway, if we did, all that info was in
| the metadata anyway:
|
| Camera: Nikon D5 F-stop: f/2.8 Exposure time: 5 sec. Focal
| length: 28mm Max aperture: 3
| supergirl wrote:
| misleading. was more like:
|
| * he got the approximate latitude from the stars (34 or 35)
|
| * independently, he found the most plausible airbase based on
| other information and then noticed that the base is indeed around
| that latitude
| johnmcelhone wrote:
| The process can still be done using entirely the star pattern
| and no Google Maps. There wasn't any reason to exclude other
| information I could use, so I didn't.
| calvinmorrison wrote:
| This has only been bested by the 4chan takedown of the Shia
| LaBeouf's anti-trump flag, which was put up in a random location
| with a live stream.
|
| "On March 8, the artists, abandoning the idea of a public webcam,
| raised a white flag, emblazoned with the words "He Will Not
| Divide Us," in an "unknown location." The livestream showed only
| the flag and the expanse of sky behind it. 4Chan and 8Chan (the
| forum where discussions that are banned from 4Chan go) snapped
| into action.... They used the star patterns visible behind the
| flag at night and the paths of planes flying overhead to confirm
| the location. A troll who lived nearby drove around honking until
| the noise was audible on the livestream. On the night of March
| 10, a group raided the site, took down the flag, and replaced it
| with a Pepe the Frog T-shirt and a "Make America Great Again"
| hat. The stream soon went dark again."
| rr888 wrote:
| Its pretty amazing some of the stories coming out of Ukraine.
| People posting on social media then getting blown up soon after.
| https://www.businessinsider.com/russia-news-exposed-mortar-c...
| [deleted]
| NotYourLawyer wrote:
| Wait, this didn't even rely on the constellations though. Get the
| latitude from the North Star and then look for matching air
| bases.
| httpz wrote:
| I thought so too but I think you need to know the
| constellations first to identify the North Star in the photo.
| johnmcelhone wrote:
| This is correct. The brightness of the stars made them a bit
| difficult to identify by eye, I'm sure someone more familiar
| with sky charts could have done it. The constellations helped
| me align the sky on Stellarium (from their angles) and the
| north star helped me find the approximate latitude by using
| the angle from the horizon.
| Victerius wrote:
| Impressive.
|
| Now do it without using a computer, the old fashioned way, with
| books, paper maps, star charts, slide rulers, sextants,
| compasses, and pens. I'm sure _some_ people would be able to.
| mberning wrote:
| I wonder how long this thing has existed. Or if it is even
| "current gen". The existence of the f117 and b2 were not
| acknowledged for a long time.
| kevmoo1 wrote:
| This is peek internet. Amazing!
| CalRobert wrote:
| That's not how you spell... Nevermind. Well done.
| dboreham wrote:
| Perhaps parent crafted a subtle pun?
| [deleted]
| omnibrain wrote:
| In my opinion peek internet was either the shoes in salad guy
| or the flagpole with only sky visible.
| teekert wrote:
| Omg I opened a Twitter thread and when that dreaded moment came
| where that black takes over the screen and I can't even scroll
| back anymore... now I was able to just tap an X and keep reading!
| Hooray for Elon?
| daveslash wrote:
| This is very cool sleuthing. Really enjoyed the walkthrough.
|
| Though, if you would have asked me, I would have _guessed_
| Lancaster /Palmdale, because I know (a) That's where the
| unveiling was (b) I have _seen_ B-1 's fly over me while driving
| in Palmdale and (c) I know Edwards and a bunch of other spacey
| stuff is there. I feel like Captain Kirk looking for whales and
| saying " _I think we 'll find what we're looking for at the
| Cetacean Institute in Sausalito_" - a far less methodical or
| impressive approach.
| mrexroad wrote:
| Ahem, not to be that person... but I think you mean Admiral
| Kirk :) Either way, it's a perfect reference.
| ChuckNorris89 wrote:
| I believe it's exactly how 4chan would keep finding Shia
| LeBeouf's flags shown on webcam he was was hiding at remote
| locations.
| Traubenfuchs wrote:
| With added train sounds and honking I believe. Excellent work!
| mc32 wrote:
| Sounds like an old Hawai'i 5-0 plot.
| nomel wrote:
| This was downvoted probably from lack of context. They used
| the sound of honking to find the exact location of the
| webcam.
| mk_stjames wrote:
| I feel like the entire thread should have led off with "This is
| in fact a publicly known hangar in Palmdale and this was known as
| public information as soon as the unveiling event occurred, and
| thus this is just an exercise to show how locating the spot could
| have been possible from just this photo as a technical
| demonstration."
|
| Because I guarantee there are going to be a hundred clickbait
| articles by various 'news' sites now in the next few days about
| the MASSIVE SECURITY BREACH of the USAF and how US SECRETS have
| been EXPOSED so and and so forth. When nothing about this is
| actually the case.
| _dain_ wrote:
| This trick happened for real with the HWNDU stunt back in 2017.
| 4channers found the flag based on the stars in the livestream,
| along with matching aircraft contrails to flight radar maps.
|
| https://youtu.be/vw9zyxm860Q
| chasd00 wrote:
| remember when 4chan figured out the location of a terrorist
| training camp from one of their PR photos and called in a
| literal airstrike? I like how 4chan is sometimes described as
| weaponized autism.
|
| https://imgur.com/N7DwWP1?r
| bauruine wrote:
| Remember when imgur was marketed as an imagehost that
| doesn't suck? Now i can't read 2/3 of the text because it's
| just a blurry mess if I'm not manually changing url
| parameters. I'm using Firefox on Android and I can't find
| another method to get the full image. Am I missing some
| button to show the full res image?
| IfOnlyYouKnew wrote:
| I feel like when you diss journalists, it should generally be
| for something they actually did wrong, not preemptively based
| on your imagination.
|
| If they are so terrible, there should be no need to invent
| stuff.
|
| When people read something like this post, and they are
| predisposed to the idea, it'll reinforce their skepticism of
| ,,the mainstream media". If you want to test yourself, make a
| bet of how many media outlets will run with the story in the
| manner outlined above, then check in a few days. My prediction:
| you won't see it in the NYT, WSJ, BBC, or on CNN.
| mk_stjames wrote:
| I put 'news' in quotes for this reason. I wasn't as much
| implying that this would be actual news, but instead would be
| used in clickbait articles on lesser publications. I admit I
| am being hypothetical, but this does reflect observation on
| how these kinds of discussions has been get picked up and
| spread and thus has made me want to avoid such writing style.
| leoh wrote:
| Right. It should be my responsibility to guard everything I say
| or write from lazy morons.
| runjake wrote:
| It's pretty clearly an exercise in astronavigation.
|
| The livestream event itself mentioned it was taking place at
| the Northrop facility in Palmdale.
|
| This author is not responsible for what clickbait farms do.
|
| Aside: I'm not even sure this plane will end up doing flight
| testing somewhere secret in Nevada. They may just do it out of
| Edwards South Base, which is an "interesting" location not many
| in the public know about.
| twelvechairs wrote:
| Also all they do is cut it down to a wide band that covers 12
| or so states, then compare against known bases (not shown) to
| narrow it down
| tablespoon wrote:
| > It's pretty clearly an exercise in astronavigation.
|
| Off topic, but it would be really cool if someone build a
| hobbyist astronavigationsystem using a something like a
| Raspberry Pi and a camera with a fisheye lens. Sort of an
| amateur https://timeandnavigation.si.edu/multimedia-
| asset/nortronics....
| johnmcelhone wrote:
| I did mention this later in the thread - was just a fun
| experiment to see if locating it was possible if we didn't know
| Sporktacular wrote:
| Sure, but the reason you didn't lead with that, and also the
| reason you did this for a secretive aircraft and not a new
| campervan is clicks, no?
| yalogin wrote:
| To be fair, a secretive aircraft would trigger thoughts
| about security in a hacker's mind. A camper van does not
| trigger any such thoughts. It may not be just clicks, with
| a camper van the whole thread might not even exist. I am
| not the original poster, so this is just my thought
| stuff4ben wrote:
| Even if he did do this for the clicks, so what?
| godels_theorem wrote:
| kyawzazaw wrote:
| so interesting
| mierle wrote:
| Wow, it's cool to see astrometry.net get put to use! I worked on
| astrometry.net back in undergrad and grad school. If you have
| questions about how it works, I can answer them.
|
| How does it work? astrometry.net uses 4-star combinations to
| define codes, then indexes the codes on the celestial sphere. The
| particulars of each of these phases matter, but that's the basic
| idea.
| tetris11 wrote:
| is A,B,C,D in the database the same as D,C,B,A? Or does order
| infer orientation?
| antognini wrote:
| I used to be in astronomy and I always thought astrometry.net
| was one of the coolest tools in the field. It feels about as
| close to magic as you can get.
| mpsprd wrote:
| Heh. This makes me remember how the same technique was used in
| the "he will not divide us" trolling campaign to locate a video
| feed of a flag. Internet Historian has a video about IIRC.
| [deleted]
| paxys wrote:
| The investigation breaks down halfway when you have to pull up a
| public list of airbase locations and google where certain jets
| are made.
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