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Finding the B-21's hangar location from the stars in its press image

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Re: Finding the B-21's hangar location from the stars in its press image

#81

Post by dekhn »

4gotunameagain wrote: post #66
pifm_guy wrote: post #59

Earlier quoted context omitted.

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.

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

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.

Re: Finding the B-21's hangar location from the stars in its press image

#82

Post by influx »

NikolaNovak wrote: post #33

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 eno…

  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

Re: Finding the B-21's hangar location from the stars in its press image

#84

Post by dragonwriter »

ForHackernews wrote: post #39
NikolaNovak wrote: post #33

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 eno…

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.

> 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.

Re: Finding the B-21's hangar location from the stars in its press image

#85

Post by a1369209993 »

Kiboneu wrote: post #19
darknavi wrote: post #9

Note to self: Always, always, ALWAYS strip exif data.

You’ve confused the data with the metadata.

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 metadata) to prevent that.

Re: Finding the B-21's hangar location from the stars in its press image

#86

Post by johnmcelhone »

httpz wrote: post #77
NotYourLawyer wrote: post #67

Wait, this didn’t even rely on the constellations though. Get the latitude from the North Star and then look for matching air bases.

I thought so too but I think you need to know the constellations first to identify the North Star in the photo.

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.

Re: Finding the B-21's hangar location from the stars in its press image

#87

Post by mrexroad »

daveslash wrote: post #23

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…

Ahem, not to be that person… but I think you mean Admiral Kirk :) Either way, it’s a perfect reference.

Re: Finding the B-21's hangar location from the stars in its press image

#88

Post by 4gotunameagain »

pifm_guy wrote: post #75
4gotunameagain wrote: post #66

Earlier quoted context omitted.

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

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.…

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.

Re: Finding the B-21's hangar location from the stars in its press image

#89

Post by cossatot »

johnmcelhone wrote: post #17
rootusrootus wrote: post #12

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.

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

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...

Re: Finding the B-21's hangar location from the stars in its press image

#90

Post by [deleted] »

NikolaNovak wrote: post #33

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 eno…

[deleted]
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