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Mike Raiford wrote:
> Could it be some artifact in the way they're getting the topology of the
> ocean floor?
I was wondering the same thing myself. Certainly there are areas of
Google's seabed images where the detail level seems to abruptly change,
with rectangular boundaries.
Personally, I just wish they had higher resolutions available. ;-) I
have a think for deep-sea exploration...
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Mike Raiford wrote:
> Could it be some artifact in the way they're getting the topology of the
> ocean floor?
Yes. The boat is going along the tracks, and the sonar forms artifacts when
it's also reflecting off the boat. Stuff like that. I read about it
somewhere when someone else brought it up, and the boat captain chimed in.
--
Darren New, San Diego CA, USA (PST)
I ordered stamps from Zazzle that read "Place Stamp Here".
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> Yes. The boat is going along the tracks, and the sonar forms artifacts
> when it's also reflecting off the boat. Stuff like that. I read about it
> somewhere when someone else brought it up, and the boat captain chimed in.
That would make sense.
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Darren New wrote:
> Yes. The boat is going along the tracks, and the sonar forms artifacts
> when it's also reflecting off the boat. Stuff like that. I read about it
> somewhere when someone else brought it up, and the boat captain chimed in.
...so the incidence of crossing lines depends on how much shipping is in
the area?
(And these features aren't part of the actual seabed...)
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On Wed, 28 Oct 2009 14:16:57 +0100, Invisible <voi### [at] dev null> wrote:
>
http://maps.google.co.uk/maps?hl=en&ie=UTF8&ll=74.781612,36.914063&spn=4.33208,28.125&t=h&z=6
>
> How random... Lots of perfectly straight lines, meeting at crisp angles.
> But what on Earth is it?
Most such artificial-looking features in Google's ocean maps are simply
data collection artifacts. Straight lines typically indicate the path of
the boat carrying the sonar equipment. Other artifacts can appear where
low-accuracy satellite-based measurements disagree with the more precise
sonar data.
--
FE
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On 10/28/2009 11:04 AM, Darren New wrote:
> Mike Raiford wrote:
>> Could it be some artifact in the way they're getting the topology of
>> the ocean floor?
>
> Yes. The boat is going along the tracks, and the sonar forms artifacts
> when it's also reflecting off the boat. Stuff like that. I read about it
> somewhere when someone else brought it up, and the boat captain chimed in.
There was an article recently in National Geographic about brand new sea
bed data from the arctic. Could be the same ship.
Mike
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Invisible wrote:
> ...so the incidence of crossing lines depends on how much shipping is in
> the area?
It was something like that, yes. I had the impression he meant the tracks
that the boat was actually on were showing up. Sonar off the boat hull and
the wake of the boat taking sonar readings.
It's also a matter of how much the boat actually measures. You get really
good resolution directly under the boat, less to the sides, so you have to
interpolate.
> (And these features aren't part of the actual seabed...)
That's the lowdown, yes.
--
Darren New, San Diego CA, USA (PST)
I ordered stamps from Zazzle that read "Place Stamp Here".
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Invisible wrote:
>
http://maps.google.co.uk/maps?hl=en&ie=UTF8&ll=74.781612,36.914063&spn=4.33208,28.125&t=h&z=6
>
>
> How random... Lots of perfectly straight lines, meeting at crisp angles.
> But what on Earth is it?
It's Russian seawalker. Nothing to be afraid of - yet.
-Aero
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Invisible <voi### [at] dev null> wrote:
>
http://maps.google.co.uk/maps?hl=en&ie=UTF8&ll=74.781612,36.914063&spn=4.33208,28.125&t=h&z=6
Martian graffiti.
--
- Warp
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Warp wrote:
> Martian graffiti.
Well, I did wonder for a moment whether it was Slartibartfast signing
his name on the seabed...
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