Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Stealth bomber in flight on Google Maps

google.com

Post reply on HN
Print view View original

91–100 of 390 posts

Re: Stealth bomber in flight on Google Maps

#91

Post by joan_kode »

ericbarrett wrote: post #52
ATsch wrote: post #42

Earlier quoted context omitted.

I would assume that the plane or satellite moving affects this too, it's presumably being corrected but there might be some parallax.

You're absolutely correct, but as the aircraft is much closer to the ground than the imaging satellite I disregarded it. Spherical cows and all that :) I'm sure a military analyst would do the calculations!

Interesting, I would have made the opposite assumption ("the satellite is moving so much faster than everything else, we can estimate the interval from the satellite's speed alone). It seems both speeds might have a similar impact, as per sibling comment.

Re: Stealth bomber in flight on Google Maps

#92

Post by trothamel »

MontyCarloHall wrote: post #9

Interesting how the three separate R/G/B images are taken independently a few ~seconds~ milliseconds apart, with a different color filter placed over the image sensor. I assume this is to maximize resolution, since no Bayer interpolation [0] is needed to demosaic the output of a traditional image sensor that integrates the color filters onto the sensor pixels themselves. As these satellites are not intended to photog…

Is it possible this is a a pushbroom sensor, where red, green, and blue sensors are moved along the path of the plane or satellite that's taking the image? My understanding is those have a higher effective resolution than frame-based sensors, which would make sense here.

Re: Stealth bomber in flight on Google Maps

#93

Post by ericbarrett »

jcims wrote: post #79
ericbarrett wrote: post #52

Earlier quoted context omitted.

You're absolutely correct, but as the aircraft is much closer to the ground than the imaging satellite I disregarded it. Spherical cows and all that :) I'm sure a military analyst would do the calculations!

It actually works out to be pretty close. A satellite flying ~17k mph at 250 miles altitude would largely have the same angular displacement from the ground as a plane moving 400 mph at 31,000 feet. Most satellites fly in an easterly direction, so the question would ultimately be what the inclination of the orbit is relative to the direction of flight.

That's super interesting! I love this discussion. Would the satellite be that low though? 250 miles (400km) is still going to experience significant atmospheric drag. Fine for a cheap mass deployment like Starlink, but I'd expect an imaging satellite to be set up for a longer mission duration. Then again maybe the cost of additional mass for station-keeping is worth it for the imaging quality.

Re: Stealth bomber in flight on Google Maps

#94

Post by goblin89 »

MontyCarloHall wrote: post #46
goblin89 wrote: post #33

Earlier quoted context omitted.

I wonder if there are ways to get superior (compared to Bayer) color images from conventional raw-capable monochrome digital cameras (like Leica Q2 Monochrom) in static scenes using similar workflows of taking three separate shots.

Absolutely! [0] In fact, the first color photos in the world were taken this way in the early 1900s [1]: take three monochrome exposures onto black and white transparencies with R/G/B filters, and then project the three images together. [0] https://leicarumors.com/2020/01/29/color-photography-with-th... [1] https://en.m.wikipedia.org/wiki/Sergey_Prokudin-Gorsky

Interesting. Sadly, I believe the Photoshop approach would not produce a DNG file that you could normally interpret in a raw processor of your choice. Looks like pixel shift cameras (which apparently still use Bayer sensors, just moving them around, to debayer at capture time so to speak) is the most practical option at the moment.

I’m curious if it is technically possible for a digital sensor to capture the entire light spectrum of the scene, without the need for RGB separation at any stage—similar to Lippmann plate[0].

[0] https://en.m.wikipedia.org/wiki/Lippmann_plate

Re: Stealth bomber in flight on Google Maps

#95

Post by [deleted] »

msisk6 wrote: post #45

I live on a farm very close to this area. All the B-2s are based at nearby Whiteman Air Force Base. They fly over often -- one even fly over my farm today about an hour ago. This one was probably on final approach during the summer when the winds are usually out of the south and was probably about 2,000 feet above the ground.

[deleted]

Re: Stealth bomber in flight on Google Maps

#96

Post by the-dude »

ericbarrett wrote: post #52
ATsch wrote: post #42

Earlier quoted context omitted.

I would assume that the plane or satellite moving affects this too, it's presumably being corrected but there might be some parallax.

You're absolutely correct, but as the aircraft is much closer to the ground than the imaging satellite I disregarded it. Spherical cows and all that :) I'm sure a military analyst would do the calculations!

Isn't the speed of the sat irrelevant as it should correct for this anyways for all images it takes?

Re: Stealth bomber in flight on Google Maps

#97

Post by Koshkin »

ericbarrett wrote: post #93
jcims wrote: post #79

Earlier quoted context omitted.

It actually works out to be pretty close. A satellite flying ~17k mph at 250 miles altitude would largely have the same angular displacement from the ground as a plane moving 400 mph at 31,000 feet. Most satellites fly in an easterly direction, so the question would ultimately be what the inclination of the orbit is relative to the direction of flight.

That's super interesting! I love this discussion. Would the satellite be that low though? 250 miles (400km) is still going to experience significant atmospheric drag. Fine for a cheap mass deployment like Starlink, but I'd expect an imaging satellite to be set up for a longer mission duration. Then again maybe the cost of additional mass for station-keeping is worth it for the imaging quality.

https://globalcomsatphone.com/satellites-and-their-altitudes...

Re: Stealth bomber in flight on Google Maps

#98

Post by ssnistfajen »

zelon88 wrote: post #80
ssnistfajen wrote: post #69

Earlier quoted context omitted.

Would be disappointing for them to remove it for basically no reason, especially considering you can see a B-2 parked on the tarmac ( https://www.google.com/maps/place/38%C2%B043'29.9%22N+93%C2%... ) in the nearby Whiteman AFB. The B-2 was first flown 32 years ago. Its existence is neither covert or secret, but often used to do flybys at freaking football games where thousands of recording devices are present and act…

Correct, but don't misunderestimate the power of knowledge. Let's assume that some adversary is out there keeping track of these planes, and knows that they can scan Google maps for the RGB artifact by the engines to locate them reliably and programmatically. Now Google maps becomes a repository for information that adversary may use to validate other information. Maybe this confirms the schedule for some training ex…

The fatal premise is assuming Google Maps updates these areas frequently enough to provide useful info. The military security implications of Google Earth have existed since its launch and Google Maps by relation is no stranger to it. This is not new info and it hardly counts as "knowledge" much less with "power".

Reconnaissance satellite technology isn't US-exclusive (https://www.dw.com/en/modern-spy-satellites-in-an-age-of-spa..., Ctrl+F "Spy satellites in numbers") and those who have a meaningful need to track B-2 movements most likely have their own tools that are up to date, more accurate, and not bound by laws or regulations a US domiciled company is subjected to. What we see on Google Maps is almost guaranted to be 100% "trash" from a military intelligence perspective because actual valuable information has always been obtainable without Google Maps for entities who are capable and in need.

Re: Stealth bomber in flight on Google Maps

#99

Post by birdyrooster »

HPsquared wrote: post #36
MontyCarloHall wrote: post #9

Interesting how the three separate R/G/B images are taken independently a few ~seconds~ milliseconds apart, with a different color filter placed over the image sensor. I assume this is to maximize resolution, since no Bayer interpolation [0] is needed to demosaic the output of a traditional image sensor that integrates the color filters onto the sensor pixels themselves. As these satellites are not intended to photog…

Doing it this way allows not only higher resolution, but you can also use different types of filter for specialist applications. Infrared for example, or some kind of narrow band pass filters etc.

Unless you aren’t military and then no infrared for you

Re: Stealth bomber in flight on Google Maps

#100

Post by notatoad »

ssnistfajen wrote: post #69
Quentak wrote: post #25

Screenshot for when it will have been deleted by Google https://i.imgur.com/toSC5a0.png .

Would be disappointing for them to remove it for basically no reason, especially considering you can see a B-2 parked on the tarmac ( https://www.google.com/maps/place/38%C2%B043'29.9%22N+93%C2%... ) in the nearby Whiteman AFB. The B-2 was first flown 32 years ago. Its existence is neither covert or secret, but often used to do flybys at freaking football games where thousands of recording devices are present and act…

i doubt they'd remove it for security reasons - as you say, there's nothing secret about what this plane is doing here. more that they'd remove it for the same reasons they remove clouds or any other in-air objects that obscure the thing they're actually trying to take photos of.

the plane isn't part of the map, so it shouldn't be on the map. even if it's not obscuring anything, they use satellite photos to generate building outlines, and this isn't a building. given how many planes there are flying all the time, and how infrequently you see them on google maps, they must make an effort to publish satellite imagery that doensn't have planes in it.

Post reply on HN