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Converting Landsat Antarctic GeoTiffs

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#1
Simmer

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Hello Guys,

This is my first post in this forum. Therefore please forgive me if I don't use the right terms here. To make my problem easier to understand I have attached some images.

What I want to do, is as follows:
I downloaded Landsat GeoTiffs from this website:
http://lima.usgs.gov/access.php

The problem is that these images are in polar stereographic projection, but I need them in geographic (?) projection. Meaning north on top and everything in degrees instead of meters.

The only tool I've found so far that can do this conversion is ERDAS Viewfinder. I just change the save properties so that ERDAS converts it to an image with geographic projection (see screen).
Problem: For one out of about a hundred Antarctica tiles this process takes about 10 (!) hours and the resulting file is about 5GB large while the original file had about 1GB. As if this wouldn't be bad enough: The file can't be opened with anything. Not Photoshop, nor IrfanView or GlobeMapper. Not even ERDAS can open its own file. It just gives me the error message: File is larger than 2G. Size will be reported as 2G.

Are there any other ways to get the GeoTiff's projection from the source mentioned above?

If someone wants to reproduce the problem:
  • Go to the wbsite mentioned above
  • Select "Natural-Color, Pan-Sharpened LIMA" and download the file with the "R" of Rothera in it by clicking into it.
  • Unpack the file
  • Open it in ERDAS Viewfinder
  • Save the file in ERDAS Viewfinder and make the settings as decribed
  • Wait forever... <_< At least 9 hours with a current computer.

Thank you very much for your help!

Bests,
Simmer

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#2
Hans van der Maarel

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If you can tell me exactly which files to get, I'd be more than happy to give it a try in Global Mapper.
Hans van der Maarel - Cartotalk Editor
Red Geographics
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#3
Simmer

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If you can tell me exactly which files to get, I'd be more than happy to give it a try in Global Mapper.


Just as decribed above. Go to http://lima.usgs.gov/access.php, select "Natural-Color, Pan-Sharpened LIMA" and click the the map as marked in the attached screenshot.

Bests,
Simmer

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#4
Hans van der Maarel

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If you can tell me exactly which files to get, I'd be more than happy to give it a try in Global Mapper.


Just as decribed above. Go to http://lima.usgs.gov/access.php, select "Natural-Color, Pan-Sharpened LIMA" and click the the map as marked in the attached screenshot.

Bests,
Simmer


Okay, I've cancelled the operation for now, will give it another shot tomorrow. The thing that's causing the file to become so big is the fact that after reprojecting, the data ends up in a sort of rotated parallellogram shape. Given that only rectangular images can be written, there's a lot of extra data around it. That's easily double the amount of pixels which makes processing go slow...
Hans van der Maarel - Cartotalk Editor
Red Geographics
Email: hans@redgeographics.com / Twitter: @redgeographics

#5
Simmer

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Okay, I've cancelled the operation for now, will give it another shot tomorrow. The thing that's causing the file to become so big is the fact that after reprojecting, the data ends up in a sort of rotated parallellogram shape. Given that only rectangular images can be written, there's a lot of extra data around it. That's easily double the amount of pixels which makes processing go slow...


Thank you very much Hans. Keep in mind that I don't really need a GeoTiff. A slightly compressed JPG with a TFW file containing the coordinate information would also be perfectly ok. Just in case it helps you to know that.

Bests,
Simmer

#6
Hans van der Maarel

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Thank you very much Hans. Keep in mind that I don't really need a GeoTiff. A slightly compressed JPG with a TFW file containing the coordinate information would also be perfectly ok. Just in case it helps you to know that.


What kind of output resolution would you want?
Hans van der Maarel - Cartotalk Editor
Red Geographics
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#7
Simmer

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What kind of output resolution would you want?


It needs to stay in the same resolution as it was before: 15m/pix

Bests,
Simmer

#8
Simmer

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Ok, after we exchanged some PMs it looks like the whole task is almost impossible to do.
Getting everthing georeferenced is no problem but saving those huge amounts of data resulting from that takes ages.

I'm still trying although not very optimistic that I will ever get anything usuable in geographic projection.

Bests,
Simmer




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