Strange reflection as seen in Google Earth

[Lev]

Hi

While playing with Google Earth, i found a place with two planes
overlapping each other:
http://213.235.28.68/temp/TwoPlanes.kmz

It looks like it is 747, probably 747-400. But i am not sure why there
are two planes in such proximity. Could it be the shadow? But why is it
in colour then? Or could it be the reflection off the clouds? But how
could the while vapour trace also reflect off the clouds?

May be it is just the spot when two photos taken at different times
been merged together, so these are two different planes (or the same
plane at different times)? But you usually clearly see such a boundary
between two photos in Google Earth. This is different. Plus chance of
taking two photos and catching a plane in almost exactly the same spot
on both of them must be rather slim

So some forensic work is required to solve this mystery. Any ideas?

Thanks

[lomcovak]

Post by Lev
May be it is just the spot when two photos taken at different times
been merged together, so these are two different planes (or the same
plane at different times)? But you usually clearly see such a boundary
between two photos in Google Earth. This is different. Plus chance of
taking two photos and catching a plane in almost exactly the same spot
on both of them must be rather slim
So some forensic work is required to solve this mystery. Any ideas?

My guess (and that's all it is) is that this has something to do with the
scanning technology. If the cameras in the satellite use multi-pass
scanning, with one scan slightly offset from the other to allow for the
movement of the satellite, then you'd get precisely this effect with a
fast-moving object.

[Steve Firth]

Post by lomcovak
My guess (and that's all it is) is that this has something to do with the
scanning technology. If the cameras in the satellite use multi-pass
scanning, with one scan slightly offset from the other to allow for the
movement of the satellite, then you'd get precisely this effect with a
fast-moving object.

If those photographs aren't taken by a satellite our explanation would be
wonderful. However they are not, they're taken from a low-flying aeroplane.

[Steve S]

Post by Steve Firth

Post by lomcovak
My guess (and that's all it is) is that this has something to do with the
scanning technology. If the cameras in the satellite use multi-pass
scanning, with one scan slightly offset from the other to allow for the
movement of the satellite, then you'd get precisely this effect with a
fast-moving object.

If those photographs aren't taken by a satellite our explanation would be
wonderful. However they are not, they're taken from a low-flying aeroplane.

OK, define "low-flying". Taking a look at the image in question we see that
the aircraft, a 747, is above the clouds and leaving contrails. Using the
Google Earth measuring tool, the overall length of the aircraft is just
under 71 metres. Note that the measuring tool is assuming you are measuring
distances at the surface. Since the actual aircraft length is 70.7 metres,
some simple geometry suggests that the image was acquired from, shall we
say, a great height.

Steve S

[Peter]

Post by Steve S
K, define "low-flying". Taking a look at the image in question we see that
the aircraft, a 747, is above the clouds and leaving contrails. Using the
Google Earth measuring tool, the overall length of the aircraft is just
under 71 metres. Note that the measuring tool is assuming you are measuring
distances at the surface. Since the actual aircraft length is 70.7 metres,
some simple geometry suggests that the image was acquired from, shall we
say, a great height.

These images are a mysterious composition of many sources.

Most of the imagery is from NASA. Then, local stuff has been filled
in, and a lot of that is still satellite but some is from aircraft.

[lomcovak]

Post by Steve S
OK, define "low-flying". Taking a look at the image in question we see
that the aircraft, a 747, is above the clouds and leaving contrails. Using
the Google Earth measuring tool, the overall length of the aircraft is
just under 71 metres. Note that the measuring tool is assuming you are
measuring distances at the surface. Since the actual aircraft length is
70.7 metres, some simple geometry suggests that the image was acquired
from, shall we say, a great height.

Just noticed something else interesting ... if you follow the contrails
back, it's the contrails from the 'shadow' image that show up much more
clearly. That suggests the 'shadow' image was obtained using a sensor with
a different spectral response to the main image. I still reckon we're
seeing two images, taken one after the other, with two different sensors. A
slight time-gap won't matter usually, nor would movement of the camera
platform (be it sat or high-altitude aircraft) because the altitude is so
great that any angular change in viewpoint is negligible. Only fast-moving
objects would be affected.

[lomcovak]

Post by Steve Firth

Post by lomcovak
My guess (and that's all it is) is that this has something to do with the
scanning technology. If the cameras in the satellite use multi-pass
scanning, with one scan slightly offset from the other to allow for the
movement of the satellite, then you'd get precisely this effect with a
fast-moving object.

If those photographs aren't taken by a satellite our explanation would be
wonderful. However they are not, they're taken from a low-flying aeroplane.

What's your source?

If it's not a sat image, then it's a very high-flying aircraft. And in any
case, it doesn't invalidate the idea.

[Steve Firth]

Post by lomcovak
What's your source?

The Google FAQ, articles that I read in Nature and a working knowledge of
satellite imagery. To the best of my knowledge Google uses two scales of
satellite imagery, fifteen metres per pixel and 61cm per pixel. Anything of
higher resolution is from aircraft. I think it has been commented before
that in several areas it is possible to see the shadow of the aircraft that
took the photographs.

Post by lomcovak
If it's not a sat image, then it's a very high-flying aircraft.

Not that high flying, the clouds don't look as high as some seem to imagine
they are.

Post by lomcovak
And in any case, it doesn't invalidate the idea.

I don't recall saying that it invalidated anything.

[lomcovak]

Post by Steve Firth
Not that high flying, the clouds don't look as high as some seem to
imagine they are.

Well, it's certainly not "low flying", which is what you said.

Post by Steve Firth

Post by lomcovak
And in any case, it doesn't invalidate the idea.

I don't recall saying that it invalidated anything.

Rereading your original comment, it's actually hard to work out what you did
mean, unless we should read 'aren't' as 'are'. If you did make a typo, then
you are clearly suggesting that, if it's aircraft imagery, it invalidates
the idea (which isn't so). If there was no typo, then your comment makes no
sense anyway and, given what you've said above, one has to assume you had
no point whatsoever. Either way, one can safely ignore you. Bye.

[N***@easily.co.uk]

Post by Lev
Hi
While playing with Google Earth, i found a place with two planes
http://213.235.28.68/temp/TwoPlanes.kmz
It looks like it is 747, probably 747-400. But i am not sure why there
are two planes in such proximity. Could it be the shadow? But why is it
in colour then? Or could it be the reflection off the clouds? But how
could the while vapour trace also reflect off the clouds?
May be it is just the spot when two photos taken at different times
been merged together, so these are two different planes (or the same
plane at different times)? But you usually clearly see such a boundary
between two photos in Google Earth. This is different. Plus chance of
taking two photos and catching a plane in almost exactly the same spot
on both of them must be rather slim
So some forensic work is required to solve this mystery. Any ideas?
Thanks

I don't have an answer but if you tilt down to about 50ft they are
both on the ground?

[skymackey]

Could they be at different altitudes?

[N***@easily.co.uk]

Post by skymackey
Could they be at different altitudes?

As mentioned in my previous reply you can tilt down to 50ft and they
are apparently on the ground?

[Steve S]

Post by N***@easily.co.uk

Post by skymackey
Could they be at different altitudes?

As mentioned in my previous reply you can tilt down to 50ft and they
are apparently on the ground?

That's because Google Earth has no data about the altitude of the aircraft.
It's the same in most areas with buildings, they look flat.

Steve S

[gAiL]

Post by Lev
It looks like it is 747, probably 747-400. But i am not sure why there
are two planes in such proximity.

It's one plane. There are a pair of contrails from either wing.

Post by Lev
Could it be the shadow? But why is it
in colour then?
Or could it be the reflection off the clouds? But how
could the while vapour trace also reflect off the clouds?

It's reflection from the cloud below, a sort of solar optical illusion -
light refraction. You often see a coloured bullseye reflection on clouds
from the sun usually in rainbow colours.
The vapor trail is probably just shadaow

G

[skymackey]

Post by gAiL
It's reflection from the cloud below, a sort of solar optical illusion -
light refraction. You often see a coloured bullseye reflection on clouds
from the sun usually in rainbow colours.
The vapor trail is probably just shadaow
G

Yep, I'm going with your reflection theory, based on further study of
the image.