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

141–150 of 390 posts

Re: Stealth bomber in flight on Google Maps

#141

Post by urschrei »

birdyrooster wrote: post #99
HPsquared wrote: post #36

Earlier quoted context omitted.

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

Nonsense. Landsat 8 bands 5, 6, and 7 are infrared bands (5 is NIR, and 6 & 7 are shortwave or SWIR), and bands 10 and 11 are lower-resolution thermal infrared (TIRS).

Source: http://www.usgs.gov/faqs/what-are-band-designations-landsat-...

Re: Stealth bomber in flight on Google Maps

#143

Post by jeffbee »

oh_sigh wrote: post #122
jeffbee wrote: post #103

Earlier quoted context omitted.

Good math. I don't know why everyone else is assuming this photo is from a spacecraft. Virtually all of the aerial images of America on Google Earth are taken with aircraft, not spacecraft.

The attribution on google maps for the image is for a satellite imaging company.

Interesting, but I'm not sure that is dispositive. That company is credited for images even where they are obviously aerial. Google Maps images are an algorithmic mash-up of many sources, I imagine they credit partial or possible sources conservatively, to keep from omitting any potentially relevant rights.

In many tiles they don't credit anybody, so the absences of Google's own image credit doesn't mean anything. The first party does not need to credit themselves.

Re: Stealth bomber in flight on Google Maps

#144

Post by littlestymaar »

mensetmanusman wrote: post #89

The new normal of 100% satellite coverage and high resolution daily pictures means future wars will be fought under water by the underdog.

I guess this comment would have been really insightful in 1910. It didn't wait for the satellites to be the norm for the underdog in a global war see [1] and [2].

[1] https://en.m.wikipedia.org/wiki/U-boat_campaign

[2] https://en.m.wikipedia.org/wiki/Battle_of_the_Atlantic

Re: Stealth bomber in flight on Google Maps

#145

Post by Scene_Cast2 »

kevin_thibedeau wrote: post #118
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…

These are pushbroom linear sensors stacked up in the focal plane. The spectral channels are physically separated by larger distance than neighboring pixels in a Bayer grid. There is a time delay between each channel sweeping over the same location that gets corrected when the final imagery is aligned. The moving plane at altitude violates assumption of a static scene and exposes the scanning behavior.

For anyone wondering about what a pushboom sensor is - http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.72....

Basically a 1D sensor that acquires a 2D image because the camera itself is moving.

In this case, I'd imagine that there are 3 such sensors for RGB.

Re: Stealth bomber in flight on Google Maps

#146

Post by carabiner »

HideousKojima wrote: post #105
zelon88 wrote: post #80

Earlier quoted context omitted.

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…

Similar to how the president brings his own toilet when doing foreign visits so enemies can't analyze his poop to see what medicines he's taking or what medical conditions he has.

Kim Jong Un does that, but I can't find record of any other world leader doing so. That takes a special level of paranoia.

Re: Stealth bomber in flight on Google Maps

#148

Post by bell-cot »

ericmay wrote: post #90

Bit of an aside but I like that the B-2 Spirit has different "Spirit of..." for each aircraft. There are Spirit of New York, Spirit of Ohio, etc. [1] Also if you're ever in Ohio and you're an aviation or engineering geek, or have kids, or are looking for something to do the USAF Museum is pretty cool! [2] [1] https://en.wikipedia.org/wiki/Northrop_Grumman_B-2_Spirit [2] https://www.nationalmuseum.af.mil/

If you are a fairly-serious aerospace, history, or military equipment buff, then allow 2 days for the USAF Museum. It's very good, and it's huge.

Re: Stealth bomber in flight on Google Maps

#150

Post by gswdh »

kevin_thibedeau wrote: post #118
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…

These are pushbroom linear sensors stacked up in the focal plane. The spectral channels are physically separated by larger distance than neighboring pixels in a Bayer grid. There is a time delay between each channel sweeping over the same location that gets corrected when the final imagery is aligned. The moving plane at altitude violates assumption of a static scene and exposes the scanning behavior.

I don’t think this is the case as we don’t see any rolling shutter distortion. The linear sensor scans just like a shutter curtain exhibiting the same distortion. The plane is proportioned correctly. Maybe the scan time is fast enough.
Post reply on HN