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Satellite Airplane

05/11/2011 4:56 PM

Saw this image in a satellite map over Jackson Park, outside of Chicago. Apparently a plane approaching either O'Hare or Midway. What causes the colors? Multiple exposures at different optical wavelengths? Some other optical phenomenon? Who's the expert on satellite photography out there?

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#1

Re: Satellite Airplane

05/11/2011 5:18 PM

The rainbow colors are actually light reflecting off the plane and then being refracted by the atmosphere on the way back to outer space.

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#3
In reply to #1

Re: Satellite Airplane

05/11/2011 6:34 PM

Off topic???

You know...

It's actually the Stealth Gayliner GS1000 entering into our dimension.

True Fact.

Or i suppose it could be 4 successive images each comprising of either a primary color, or chromatic taken just quick enough to create colors from a moving object...

"imagery satellites have different types of sensors: grayscale, red, green, blue. the sensors are arranged in a line, and each takes a photo as the satellite moves. each photo is taken at a different time, but at the same location relatively to the earth. then image is then created from the data of the different sensors. this is why there are problems with moving objects."

Nope... Definitely the Gayliner Entering from another dimension... Those darn light particles are bending through space and time!

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#2

Re: Satellite Airplane

05/11/2011 5:23 PM

How did you get this image of the new anti-terrorist commercial airliner?!?

Now that I've said my stupid joke, its obvious that somewhere in the displayed image acquisition the blue image was captured first, then green, then red, then the B/W contrast or intensity image. Now this time skewed image may have been generated in the image sensor on the satellite, but I doubt it. More than likely it came from some shuffling of which individual frame any of the software links between satellite and your computer was grabbing before you saw the image. I wouldn't be surprised if a relatively slow link in the chain could produce a different sequence order.

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#4

Re: Satellite Airplane

05/11/2011 7:04 PM

ROY-G-BIV

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#5

Re: Satellite Airplane

05/11/2011 7:17 PM

It looks like the camera taking the photograph is a monochrome camera with a 3-color plus IR filter wheel. As the camera took the picture through each filter, the plane moved, yielding the image you see as the software aligned the colors for the scenery below.

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#7
In reply to #5

Re: Satellite Airplane

05/11/2011 8:50 PM

I believe you hit the nail on the head.

Clues are the colors themselves and the time interval between color changes is consistent.

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#6

Re: Satellite Airplane

05/11/2011 8:02 PM

It's Unicorn Magic!

Burn the witches!

(Going for off topic record)

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#8

Re: Satellite Airplane

05/11/2011 10:02 PM

My first thought was like RVZ717's--differential refraction--but then the colors should have been "smeared" into a rainbow. The distinct images make me go with USBPort's description (GA).

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#9

Re: Satellite Airplane

05/11/2011 10:22 PM

I'm still not sure if this was a data shuffle or a consequence of the camera's normal color imaging technique. Finding another aircraft image and the order of the images will convince me which. I do believe that the time interval increment between each image was the same. A very close inspection of the wing tip interval distances tells me that this plane is making a left turn.

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#10
In reply to #9

Re: Satellite Airplane

05/12/2011 1:07 AM

Good eye!

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#13
In reply to #9

Re: Satellite Airplane

05/12/2011 6:58 AM

The technique of compound exposure at different wavelengths is a common one used in astrophotgraphy, so it seems reasonable to believe this is an older space based or high altitude camera system.

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#11

Re: Satellite Airplane

05/12/2011 3:57 AM

Whatever....a beautiful photograph...rainbow too !

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#12

Re: Satellite Airplane

05/12/2011 5:49 AM

Hang on a minute: this photo was surely taken by another aeroplane. If it was a satellite then the aeroplane would be pretty much the same scale as the underlying scenery. Because it's huge compared to the underlying fields and trees it must have been "relatively" close to the camera.

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#14
In reply to #12

Re: Satellite Airplane

05/12/2011 7:39 AM

Interesting point. According to Wikipedia:

Although Google uses the word satellite, most of the high-resolution imagery is aerial photography taken from aircraft flying at 800-1500 feet rather than from satellites.

So I should adjust my original response slightly and say that both airplanes were moving when the camera took the photograph, etc.

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#15
In reply to #14

Re: Satellite Airplane

05/12/2011 7:44 AM

Thanks.

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#19
In reply to #12

Re: Satellite Airplane

05/12/2011 1:33 PM

Nope, it must be satellite

the zoom indicator is close to maximum. Check it on Google maps.

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#20
In reply to #19

Re: Satellite Airplane

05/12/2011 1:41 PM

LOL

The Google zoom indicator is the proof. You're so funny.

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#21
In reply to #20

Re: Satellite Airplane

05/12/2011 1:48 PM

Hey, Thats scientific evidence that the picture was taken from some place higher in altitude than the plane. Now we know for sure that the picture was not taken from my balcony.

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#27
In reply to #20

Re: Satellite Airplane

05/12/2011 5:59 PM

If one cannot trust Google any more , who else can one trust?

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#28
In reply to #27

Re: Satellite Airplane

05/12/2011 7:51 PM

Trust no one.

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#22
In reply to #19

Re: Satellite Airplane

05/12/2011 1:48 PM

I'm tending to agree (although not for the same reasons).

If this were an aerial image, how are the multiple shots/spectrums of the plane explained?

If this were a satellite image, it could be explained that each spectrum could be shot (RGB) individually (and then put together later) followed by a BW. (Note typical aerials take one shot for the area, not counting overlap)

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#16

Re: Satellite Airplane

05/12/2011 9:49 AM

From the late 60's Timothy Leary's plane possibly

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#17

Re: Satellite Airplane

05/12/2011 11:11 AM

Can anyone identify the type of plane?

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#18
In reply to #17

Re: Satellite Airplane

05/12/2011 11:47 AM

737?

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#23
In reply to #18

Re: Satellite Airplane

05/12/2011 5:01 PM

Yup, looks like a 737.

We can probably verify this somewhere on the internet using the tail number - L08708 that's visible in the image.

OK just kidding about the tail number

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#24
In reply to #23

Re: Satellite Airplane

05/12/2011 5:31 PM

OK... so assuming....

1) it's a 737

2) the information I found regarding the glide slope for a landing is correct ... the shallowest angle being 2.5 degrees.

3) it is landing at O'hare (20.9 miles away)

and

4) a standard aerial image (taken by plane) is flown at 1000ft +/-

(I know ... it's alot... feel free to shoot 'em down... no pun intended )

A quick trig problem (height plane = 20.9miles * tan 2.5 deg) would put the plane in the image at about 4800ft (much higher than the plane taking the standard aerials).

So far my vote is with Anonymous Hero for compound exposure from a satellite.

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#25
In reply to #24

Re: Satellite Airplane

05/12/2011 5:39 PM

So maybe its in a holding pattern above the landing glide path.

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#26
In reply to #25

Re: Satellite Airplane

05/12/2011 5:42 PM

4800 feet sounds about right for approach altitude, for 20 miles out. I know it depends on the airport, too.

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#29
In reply to #24

Re: Satellite Airplane

05/13/2011 5:38 AM

I agree that it's probably a 737:-

But if you compare the image with the 50ft ground dimension in this image:-

Or, with the car (if you don't trust google) in this image:-

The plane is "apparently" about 350 feet long.

Now, in fact a 737 is 138 feet long

So if you go back to your trig it looks to me as though the camera is about 2½ times further away from the ground than it is from the plane. Or if the camera is at the max height for google photographs i.e. 1500 ft the 737 must be at about 1200 ft, and, I imagine that the pilot of the google plane was more than a little worried when the 737 passed only 300 feet beneath him.

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#31
In reply to #29

Re: Satellite Airplane

05/13/2011 9:11 AM

Sorry, don't know how I managed to duplicate the next thread, but I did.

I think I had two browsers opened at the same time, and got confused, a condition I find all too often any more.

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#32
In reply to #29

Re: Satellite Airplane

05/13/2011 9:14 AM

No commercial aircraft would be at 1,200 feet AGL at 20 miles from the airport.

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#33
In reply to #32

Re: Satellite Airplane

05/13/2011 9:42 AM

Unless it was ducking to avoid some idiot taking pictures.

Seriously though the ratio still clearly holds: if the 737 was at 6,000 feet the camera was at about 10,000 feet.

Huh! I think I got my previous guess wrong: just trying to get into the right ball park.

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#34
In reply to #29

Re: Satellite Airplane

05/13/2011 11:24 AM

It's a 737-291. Manufactured in 1978, with P&W JT8D engines, which explains why they appear longer than the newer versions with more modern, shorter engines.

It's owned by an aviation service out of Hot Springs, AR. USA.

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#35
In reply to #34

Re: Satellite Airplane

05/13/2011 11:30 AM

Why would they need an aircraft with psychedelic stealth capabilities?

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#36
In reply to #35

Re: Satellite Airplane

05/13/2011 11:58 AM

I'll ask them the next time I'm in Hot Springs.

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#30
In reply to #23

Re: Satellite Airplane

05/13/2011 9:07 AM

If you zoom in on Google Streetview you can see it is N981UA, an old 737 Series 200.

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#37

Re: Satellite Airplane

05/16/2011 10:25 AM

So without knowing the exact details of what type of sensor was used, I don't think it's possible to say for sure.

I think we need to keep in mind that many satellites don't take a whole image at a time. There are different types, but most use a CCD array and scan the area. This means the entire image is not time synchronous (take a look at the cars in the image, although less pronounced because of a slower velocity than the plane, there are still the color artifacts trailing the vehicles). So if we assume a common type sensor, such as a push-broom type, with arrays for each band pass, the conclusions make sense. So while one array is scanning a line in band A, another would be scanning the line in band B behind it. In the next time step, band B would acquire the same spatial data that band A just got (and band A pushes ahead).

Many satellite images you can't think of like your camera. Your camera takes a whole image with all bands in one instant. But because of the distances and resolutions involved with remote sensing, satellite sensors are often like the scanner on your all-in-one printer (with multiple lines for each band).

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