Creating a path from Satellite to Earth

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BeelerVI

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Aug 30, 2007, 9:46:05 AM8/30/07
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Does anyone know if you can create a path from a point in space (i.e.,
a Satellite location) to a specific geographic location on the Earth?

I have extended a line from the satellite to the Earth but I want to
visualize a line from the satellite along it's line-of-sight to a
different point on the Earth.

When I tried to create such a path, it puts in on the surface of the
Earth (i.e., from the sub-satellite point to the other geographic
point) rather than through space.

Thanks!

ManoM

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Aug 30, 2007, 1:34:24 PM8/30/07
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Hi BeelerVI,

Earth and Sky mode are two separate modes that currently don't
connect. If you create KML files, Sky KML and Earth KML will both show
up in both modes. The difference is that any KML file that has this as
the root element:
<kml xmlns="http://earth.google.com/kml/2.2" hint="target=sky">
will suggest that you open it in Sky mode, if you're in Earth, and
anything without it will suggest you open in Earth mode, if you're
already in Sky.

The one thing you could do is create a link in a description balloon
which will open up another KML file that has the other mode. So for
instance, if you're in Earth mode, you can create a link to your Sky
KML:
<a href="test-sky.kml#testsky;flyto">click here for Sky KML</a>

For more information, check out the reference of the description
element:
http://code.google.com/apis/kml/documentation/kml_tags_beta1.html#description

ManoM

SEWilco

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Aug 31, 2007, 11:32:25 AM8/31/07
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Original poster did not mention Sky mode. Although there are many
satellite orbits, I suspect he wants to draw a line from a point on
Earth to a geosynchronous satellite. I think he wants to draw a line
from one coordinate and altitude to a different coordinate and
altitude.

ManoM

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Aug 31, 2007, 4:28:40 PM8/31/07
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Hi SEWilco,

Thanks for pointing that out. I guess I just have Sky on the brain.
BeelerVI, if you are are still having trouble with this, post you're
code and we'll figure out a way to do this. It should be easy.

ManoM

simon_a

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Sep 1, 2007, 5:19:38 AM9/1/07
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Hello,

Have a look at this similar post from the GE Support Group:
http://groups.google.com/group/earth-free/browse_thread/thread/c41f3d9d0b9bcf3a

:-)

Simon.

BeelerVI

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Sep 4, 2007, 9:59:41 AM9/4/07
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Thanks for your ideas everyone, I did figure it out. It was a simple
problem actually - I just had to specify the altitudeMode. Apparently
it is "clampedToGround" by default, that's why it was drawing the line
on the Earth surface. Once I added <altitudeMode>absolute</altitude>
it worked the way I intended.

Indeed as SEWilco mentioned, I was trying to draw a line (path)
representing a line-of-sight from a satellite to a point on Earth.

Thanks

BeelerVI

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Sep 4, 2007, 10:13:50 AM9/4/07
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I tried to give that guy a snip from my code as an example how to
write the KML code to do it but I'd have to join that group first.
Could you forward this to him?

Thanks.

<LineString>
<tessellate>1</tessellate>
***<---I'm not sure he would want this on or not
<altitudeMode>absolute</altitudeMode>
<coordinates>-75,30,1000,-75.,30.5,0</coordinates> ***<---
check units for altitude, this is just an example
</LineString>

On Sep 1, 5:19 am, simon_a wrote:
> Hello,
>

> Have a look at this similar post from the GE Support Group:http://groups.google.com/group/earth-free/browse_thread/thread/c41f3d...

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