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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

#41

Post by Rebelgecko »

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…

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

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

#43

Post by tetris11 »

mierle wrote: post #26

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.

is A,B,C,D in the database the same as D,C,B,A? Or does order infer orientation?

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

#44

Post by lmm »

Denvercoder9 wrote: post #27
Kiboneu wrote: post #19

Earlier quoted context omitted.

You’ve confused the data with the metadata.

Exif data is the metadata of the image.

Exactly, whereas stars shown in the image are just data, you don't need the exif data to see them.

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

#45

Post by antognini »

mierle wrote: post #26

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.

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.

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

#46

Post by avalys »

boardwaalk wrote: post #10

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…

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.

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

#47

Post by insane_dreamer »

lmm wrote: post #44
Denvercoder9 wrote: post #27

Earlier quoted context omitted.

Exif data is the metadata of the image.

Exactly, whereas stars shown in the image are just data, you don't need the exif data to see them.

But the time the photo was taken was extracted from the exif which is what OP was referring to stripping

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

#48

Post by chasd00 »

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…

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?

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

#49

Post by lambdasquirrel »

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.

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.

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

#50

Post by pifm_guy »

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.

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