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NetCDF to Raster   Luke Spence Feb 16, 2007
Re: NetCDF to Raster   Jean-Yves Gindre Feb 20, 2007
Re: NetCDF to Raster   Luke Spence Feb 22, 2007
Re: NetCDF to Raster   Luke Spence Mar 09, 2007
Re: NetCDF to Raster   Charlotte Liner Mar 28, 2007
Re: NetCDF to Raster   Charlotte Liner Mar 28, 2007
Re: NetCDF to Raster   Alex Tate Apr 03, 2007
Re: NetCDF to Raster   Jennifer Boehnert Apr 04, 2007
Re: NetCDF to Raster   Jennifer Boehnert Apr 04, 2007
Re: NetCDF to Raster   Jonathan W Dec 21, 2007
Re: NetCDF to Raster   Matteo Spagnolo Jan 09, 2008
Re: NetCDF to Raster   Brad Posthumus Jul 11, 2008
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Subject NetCDF to Raster 
Author Luke Spence 
Date Feb 16, 2007 
Message I'm trying to import a NetCDF file to ArcView 9.2. I'm using the MultiDimensional Tools: "Make NetCDF Raster Layer" Tool. I get an error saying that "One or both dimensions have variable spacing in their coordinate values". What does this mean?

When I looked for help on ESRI's support page, I saw that they say the spacing between the x-coordinates and the y-coordinates must be equal. Mine are, as far as I can tell (the cell size is the same for x and y directions). ESRI recommends that I creat a NetCDF feature layer and then interpolate to raster (not quite sure what "interpolate to raster" means, any ideas?). I tried to follow their advice and got more problems.

When I go to create a NetCDF feature layer (using the "Make NetCDF feature layer" tool), it gets imported as a single point. This doesn't seem right. This all leads me to believe that maybe my NetCDF files are not in the exact right format. Does ESRI have a specified standard that NetCDF files must follow to be readable in Arc? Any help on what steps I should take now? 
   
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Subject Re: NetCDF to Raster 
Author Jean-Yves Gindre 
Date Feb 20, 2007 
Message We encounter exatly same problems. Did you find any solution? 
   
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Subject Re: NetCDF to Raster 
Author Luke Spence 
Date Feb 22, 2007 
Message No solution yet...

We are in the process of comparing a file that works with one that doesn't. Hopefully we can narrow down the problem. ArcView is supposed to be able to read NetCDF files that are "CF or COARDS compliant". 
   
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Subject Re: NetCDF to Raster 
Author Luke Spence 
Date Mar 09, 2007 
Message I believe we solved the problem. Our latitude and longitude vectors in the NetCDF files were written in single precision. I think this was causing the lat/lon values to be rounded, which ended up giving a "variable" cell spacing across the grid. Now we write in double precision, which allows the lat/lon values to be written "exactly". The files import OK, now. 
   
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Subject Re: NetCDF to Raster 
Author Charlotte Liner 
Date Mar 28, 2007 
Message Hi,
I have the same problem but as I am new with netCDF data I donīt know how to change the data. Could anyone help me?
Thanks! 
   
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Subject Re: NetCDF to Raster 
Author Charlotte Liner 
Date Mar 28, 2007 
Message Ok, I could change the data and ArcGIS imported it without any error messages but all I get is just one point without any data. Ideas what I did wrong? 
   
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Subject Re: NetCDF to Raster 
Author Alex Tate 
Date Apr 03, 2007 
Message Hi,
I am also having issues with the NetCDF import functions. I produce COARDS compliant NetCDF grids using GMT v4.1 but ArcGIS 9.2 complains about variable spacing even though the grdinfo command shows equal spacing. I have output to double precision but the problem remains and I also get no joy from importing to a feature. I have waited a long time to view all my GMT grids in Arc and it looks like I'll have to wait a little longer.

Alex 
   
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Subject Re: NetCDF to Raster 
Author Jennifer Boehnert 
Date Apr 04, 2007 
Message Alex,
Odds are your data is in geographic coordinates so the grid spacing will be slightly off. You will have to bring this data in as a Feature layer and then convert to a grid. Or what we have done is wrote an NCL script to convert the geographic coordinates to Lambert Conformal so they are evenly spaced then we can bring it in as a raster.
Jennifer 
   
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Subject Re: NetCDF to Raster 
Author Jennifer Boehnert 
Date Apr 04, 2007 
Message Hi Charlotte,
You only got one point because you did not specify your Row Dimensions. This is very important when you import to a table or a feature class it will determine how many feature you get. The Row Dimension should be your lat, lon or your south_north, west_east dimensions.

Here is what the command should look like
gp.MakeNetCDFTableView_md(wrfout_jme_nc, "WTHRSH_MTHD1;WTHRSH_MTHD2;XLAT;XLONG", FLAGnc, "south_north;west_east", time_value, "BY_VALUE")


Jennifer
 
   
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Subject Re: NetCDF to Raster 
Author Jonathan W 
Date Dec 21, 2007 
Message I am trying to import into ArcMap 9.2 world bathymetry grid files from
ftp://topex.ucsd.edu/pub/global_topo_1min
along with various other bathymetry datasets that are grd files
http://www.gina.alaska.edu/page.xml?group=data&page=griddata

I understand that they are made in GMT but according to ArcMap 9.2 Help Files they should easily work in ArcMap. Is there any way to view these files in ArcMap without having to download a UNIX emulator and GMT?
 
  Jonathan
Tyco Telecommunications
GIS Specialist 
   
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Subject Re: NetCDF to Raster 
Author Matteo Spagnolo 
Date Jan 09, 2008 
Message I am having a similar problem with some .grd bathymetric files that are in a GMT NETCDF format. In no way I can open them in ArcGis 9.2.
Did you manage to solve you problem? Can you tell me how?
Matteo 
   
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Subject Re: NetCDF to Raster 
Author Brad Posthumus 
Date Jul 11, 2008 
Message See this post:

http://forums.esri.com/Thread.asp?c=93&f=1740&t=228607