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Trouble showing lunar poles [message #64309] Mon, 15 December 2008 23:05 Go to next message
Gaurav is currently offline  Gaurav
Messages: 50
Registered: January 2007
Member
Dear all,
I am trying to code an application to display the lunar imagery warped
on a sphere. The images that I am using are 100 metre resolution
images obtained from the Clementine mission.

The images pertaining to the non polar regions (in geographic
projection) of the moon can be easily warped on a sphere using the
sphere(4) surface type option in MESH_OBJ. But for the polar regions,
the image in the same projection becomes very bulky (of the order of
1.5 GBs).

The dataset also contains a mosaic of the polar region that shows the
region above 80 degrees latitude as it would look from a point right
above the poles. A snapshot of the north pole image is at:

http://img208.imageshack.us/img208/7199/moonnpolels0.jpg

Now, this image is not very bulky and I would love to use it. The
trouble is, I don't know how. As I would move towards the centre of
the image from any edge, the latitude values would increase whereas
the longitude values change in a circular fashion-quite different from
regular non-polar images where all the four corners have distinct
coordinates. Do I use polar surface type in MESH_OBJ, and if so, how?
In short if one had to warp an image at the poles of a sphere, how
would one go about it.

I tried to look it up in old posts but I presume I am not being able
to phrase my query properly. Any code snippets or pointers would be
highly appreciated.

Regards,
Gaurav
Re: Trouble showing lunar poles [message #64370 is a reply to message #64309] Wed, 17 December 2008 20:19 Go to previous message
Gaurav is currently offline  Gaurav
Messages: 50
Registered: January 2007
Member
Dear All,
Will this be the first time I will have to turn away without a
solution to my query from this wonderful group of ever helpful IDL
users?

I don't suppose my problem is such a unique one after all and as far
as I can see it, I have decribed it as well as I could. Please help me
with pointers in the right direction. I look up to you guys all the
time.

Regards,
Gaurav
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