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Longitudinal Values for World Data (+/-)

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#1
geografa

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Greetings,

I am seeking advice in working with world data sets where the GCS has a positive range (0 degrees to 360 degrees). The data I am working with are NetCDF oceanographic data and have positive coordinate values as mentioned. When displayed in a normal GCS in ESRI's ArcGIS 10, it is offset from other data that exist in the range of -180 to 180. If I reproject it, gaps occur around the prime meridian (mostly due to its origins, sometimes as far off as 25 degrees W). My thought is to create a custom projection/coordinate system that has the positive values and hope that other world data sets reproject on the fly just fine. Does anyone see any issues with this or have other solutions? Hope this makes sense. I appreciate any help in advance.

Edited by geografa, 25 May 2011 - 02:15 PM.


#2
frax

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Have you tried the shift tool in the toolbox? You might need to split up the data in two pieces though, but that should be easy to do. I have gotten very comfortable with the python commandline, it would be easy to prepare a few lines of code that you can paste in to use on multiple datasets.
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#3
Laura Miles

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Maybe you could try modifying the coordinates, subtract (the values over 180) by 180 and then multiply by -1 to create negative values.
Laura




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