[GRASS-user] NetCDF rotated pole

[Michael Barton]

Excellent!

I was warned here at NCAR that I would have a lot of trouble with these model data file unless I could find someone to help me with the arcane NCAR Computer Language (NCL) code to reproject them. When I said that with GRASS, georeferencing would not be that big a deal if I could somehow find proper geographic reference points or data layers, they were skeptical. Persistence paid off, however. I still don't have NCL working (though I want to try it), but the approach I sent you turned out very well for my data. It may even be better than the NCL approach, since NCL seems to use a simple bilinear interpolation to directly change the grid cells from POP grid to latlon. With mine, we reproject grid centers first before interpolating. We can then choose which interpolator works best for our particular question and data set.

Michael

On Mar 21, 2012, at 8:51 AM, Eduardo Klein wrote:

> Michael,
> 
> Thanks a lot for the instructions. It worked perfectly on my files!
> 
> Saludos, EKS
> 
> 
> On 03/20/2012 05:42 PM, Michael Barton wrote:
>> Edwardo,
>> 
>> I am attaching a PDF and RTF of the workflow I used to import paleocurrent data from a NetCDF file with rotated poles. While it may not exactly match your file, it should give you an idea of how to proceed. Let me know how it comes out.
>> 
>> 
>> 
>> 
>> 
>> Michael
>> 
>> On Mar 20, 2012, at 6:18 AM, Eduardo Klein wrote:
>> 
>>> Thanks Michael, your advice will be much appreciated!.
>>> 
>>> Saludos, EKS
>>> 
>>> 
>>> On 03/19/2012 04:39 PM, Michael Barton wrote:
>>>> I'm at NCAR right now and I'm doing that very thing today in fact.
>>>> 
>>>> Once I have an answer as to the difference between TLAT and ULAT, and TLONG and ULONG within the NetCDF files, I'll be able to give you a full work flow for this.
>>>> 
>>>> Michael
>>>> 
>>>> On Mar 19, 2012, at 2:44 PM,<grass-user-request at lists.osgeo.org>   wrote:
>>>> 
>>>>> Message: 3
>>>>> Date: Mon, 19 Mar 2012 13:20:33 -0430
>>>>> From: Eduardo Klein<eklein at usb.ve>
>>>>> Subject: [GRASS-user] NetCDF rotated pole
>>>>> To: grass-user at lists.osgeo.org
>>>>> Message-ID:<4F6771E9.2080301 at usb.ve>
>>>>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>>>> 
>>>>> Hi,
>>>>> 
>>>>> Is there any way to read a NetCDF file which has a rotated pole Mercator
>>>>> projection and have it inside GRASS with the North pole at North?
>>>>> 
>>>>> I'm trying to use AVISO SSH products on GRASS 6.4.1 and gdal 1.8.0
>>>>> 
>>>>> Thanks!
>>>>> 
>>>>> --
>>>>> Eduardo Klein
>>>>> Lab Sensores Remotos e
>>>>> Instituto de Tecnolog?a y Ciencias Marinas
>>>>> Universidad Sim?n Bol?var
>>>>> Caracas, Venezuela
>>>>> ph (58) (212) 906-3111 ext 6700
>>>>> fax (58) (212( 906-3111 ext 6701
>>>> 
>>>> _____________________
>>>> C. Michael Barton
>>>> Visiting Scientist, Integrated Science Program
>>>> National Center for Atmospheric Research&
>>>> University Corporation for Atmospheric Research
>>>> 303-497-2889 (voice)
>>>> 
>>>> Director, Center for Social Dynamics&   Complexity
>>>> Professor of Anthropology, School of Human Evolution&   Social Change
>>>> Arizona State University
>>>> www: http://www.public.asu.edu/~cmbarton, http://csdc.asu.edu
>>>> 
>>> 
>>> --
>>> Eduardo Klein
>>> Lab Sensores Remotos e
>>> Instituto de Tecnología y Ciencias Marinas
>>> Universidad Simón Bolívar
>>> Caracas, Venezuela
>>> ph (58) (212) 906-3111 ext 6700
>>> fax (58) (212( 906-3111 ext 6701
>> 
>> _____________________
>> C. Michael Barton
>> Visiting Scientist, Integrated Science Program
>> National Center for Atmospheric Research&
>> University Consortium for Atmospheric Research
>> 303-497-2889 (voice)
>> 
>> Director, Center for Social Dynamics&  Complexity
>> Professor of Anthropology, School of Human Evolution&  Social Change
>> Arizona State University
>> www: http://www.public.asu.edu/~cmbarton, http://csdc.asu.edu
>> 
>> 
>> 
>> 
>> 
> 
> -- 
> Eduardo Klein
> Lab Sensores Remotos e
> Instituto de Tecnología y Ciencias Marinas
> Universidad Simón Bolívar
> Caracas, Venezuela
> ph (58) (212) 906-3111 ext 6700
> fax (58) (212( 906-3111 ext 6701

_____________________
C. Michael Barton
Visiting Scientist, Integrated Science Program
National Center for Atmospheric Research &
University Corporation for Atmospheric Research
303-497-2889 (voice)

Director, Center for Social Dynamics & Complexity 
Professor of Anthropology, School of Human Evolution & Social Change
Arizona State University
www: http://www.public.asu.edu/~cmbarton, http://csdc.asu.edu