[GRASS-dev] Re: [GRASS-user] how to import NetCDF data??

Wed Feb 8 12:57:42 EST 2012

This will be even more important with Soren's new temporal GIS framework. Many netcdf climate files are the equivalent of 'time-cubes'. Being able to read/write these easily would provide a very rich source of data to use in temporal GIS analyses.

Michael
____________________
C. Michael Barton
Director, Center for Social Dynamics & Complexity 
Professor of Anthropology, School of Human Evolution & Social Change
Arizona State University

voice: 	480-965-6262 (SHESC), 480-727-9746 (CSDC)
fax:          480-965-7671 (SHESC),  480-727-0709 (CSDC)
www: http://www.public.asu.edu/~cmbarton, http://csdc.asu.edu

On Feb 8, 2012, at 10:14 AM, Jennifer Boehnert wrote:

> Thank you everyone for all the support, suggestions and feedback.  I am 
> trying to create a course using GRASS which I would teach in Latin 
> America and eventually hopefully in Africa working on vulnerability 
> assessements using climate change model output from NCAR.  My netCDF 
> data is from the CCSM which was in by the IPCC AR4, it is netCDF3 and 
> using the CF-convention.  It is a pretty typical netCDF file and it 
> would be great if we could read it into GRASS directly without having to 
> convert it to a geotiff or any other format, if possible.
> Thanks Jennifer
> 
> 
> On 2/8/2012 10:05 AM, Michael Barton wrote:
>> Lack of NetCDF support would be a problem for sure. We wondered about
>> that. Jennifer is trying on Windows and I'm on a Mac.
>> 
>> Michael
>> ____________________
>> C. Michael Barton
>> Director, Center for Social Dynamics & Complexity
>> Professor of Anthropology, School of Human Evolution & Social Change
>> Arizona State University
>> 
>> voice: 480-965-6262 (SHESC), 480-727-9746 (CSDC)
>> fax: 480-965-7671 (SHESC), 480-727-0709 (CSDC)
>> www: http://www.public.asu.edu/~cmbarton, http://csdc.asu.edu
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> On Feb 8, 2012, at 9:16 AM, Kirk Wythers wrote:
>> 
>>> Michael,
>>> 
>>> I could not open the file in GRASS either. I have attached the errors
>>> I got. They look like the same that you were describing (I tried both
>>> with and without the -o flag). I did however remember the work around
>>> I used, which was to:
>>> 
>>> 1. import the .nc files into MATLAB
>>> 2. Export as GeoTIffs
>>> 3. Read the GeoTiffs into GRASS
>>> 
>>> This made sense for me partly because I needed to aggregate daily
>>> values to monthly means which I did in step 1, but then never thought
>>> much more about why I couldn't import directly into GRASS . Your
>>> problem motivated me to look into why I needed this workaround in the
>>> first place (which is not much of a workaround unless you have access
>>> to MATLAB)… which appears to be that my gdal does not have GMT/netcdf
>>> support either (as Markus pointed out yesterday). I am also using
>>> WIlliams binaries and frameworks.
>>> 
>>> I agree that more detail in the wiki would be helpful, but I think the
>>> first step is to compile to update gdal with GMT/NetCDF support.
>>> Perhaps William would be interested?
>>> 
>>> 
>>> ===================================================================================================================================
>>> GRASS ERRORS:
>>> 
>>> 
>>> GRASS 6.4.1 (latlon):~ > r.in.gdal
>>> input=~/Desktop/ppt_SRESA2_mid_annual_down_anomaly.nc
>>> output=ppt_SRESA2_mid_annual_down_anomaly
>>> ERROR: Projection of dataset does not appear to match current location.
>>> 
>>> Location PROJ_INFO is:
>>> name: Lat/Lon
>>> proj: ll
>>> datum: nad83
>>> ellps: grs80
>>> towgs84: 0,0,0,0,0,0,0
>>> no_defs: defined
>>> 
>>> Import dataset PROJ_INFO is:
>>> cellhd.proj = 0 (unreferenced/unknown)
>>> 
>>> You can use the -o flag to r.in.gdal to override this check and use
>>> the location definition for the dataset.
>>> Consider generating a new location from the input dataset using the
>>> 'location' parameter.
>>> 
>>> GRASS 6.4.1 (latlon):~ > r.in.gdal -o
>>> input=~/Desktop/ppt_SRESA2_mid_annual_down_anomaly.nc
>>> output=ppt_SRESA2_mid_annual_down_anomaly
>>> WARNING: Over-riding projection check
>>> WARNING: G_set_window(): Illegal latitude for North
>>> GRASS 6.4.1 (latlon):~ >
>>> ===================================================================================================================================
>>> 
>>> 
>>> On Feb 7, 2012, at 9:10 PM, Michael Barton wrote:
>>> 
>>>> Thanks Kirk,
>>>> 
>>>> Here is a copy of the smallest file we tried. The big ones gave
>>>> identical errors.
>>>> 
>>>> Michael
>>>> 
>>>> <ppt_SRESA2_mid_annual_down_anomaly.nc>
>>>> 
>>>> ____________________
>>>> C. Michael Barton
>>>> Director, Center for Social Dynamics & Complexity
>>>> Professor of Anthropology, School of Human Evolution & Social Change
>>>> Arizona State University
>>>> 
>>>> voice: 480-965-6262 (SHESC), 480-727-9746 (CSDC)
>>>> fax: 480-965-7671 (SHESC), 480-727-0709 (CSDC)
>>>> www: http://www.public.asu.edu/~cmbarton, http://csdc.asu.edu
>>>> <http://csdc.asu.edu/>
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> On Feb 7, 2012, at 11:49 AM, Kirk Wythers wrote:
>>>> 
>>>>> I had to import a bunch of SSURGO NetCDF data not too long ago
>>>>> Michael (I was going back and forth with GRASS and MATLAB). I don't
>>>>> seem to remember having any trouble with gdal (which means that it
>>>>> must have worked!) Are you sure that the NetCDF is Lat Long?
>>>>> 
>>>>> What was your error exactly? Is the file too big to share? If not
>>>>> send it to me and I'll take a look.
>>>>> 
>>>>> Best,
>>>>> 
>>>>> Kirk
>>>>> 
>>>>> Kirk R. Wythers
>>>>> Department of Forest Resources
>>>>> University of Minnesota
>>>>> St. Paul, MN 55108
>>>>> tel: 612.625.2261
>>>>> email: kwythers at umn.edu <mailto:kwythers at umn.edu>
>>>>> 
>>>>> 
>>>>> On Feb 7, 2012, at 12:33 PM, Michael Barton wrote:
>>>>> 
>>>>>> I'm trying to help someone at NCAR import NetCDF data and we keep
>>>>>> getting an illegal north latitude error. Looking at the GDAL info,
>>>>>> I think we need to specify some additional metadata, but the GDAL
>>>>>> page stops short of giving an example of how to do this. Has anyone
>>>>>> imported climate data this way?
>>>>>> 
>>>>>> Thanks
>>>>>> Michael
>>>>>> ____________________
>>>>>> C. Michael Barton
>>>>>> Director, Center for Social Dynamics & Complexity
>>>>>> Professor of Anthropology, School of Human Evolution & Social Change
>>>>>> Arizona State University
>>>>>> 
>>>>>> voice: 480-965-6262 (SHESC), 480-727-9746 (CSDC)
>>>>>> fax: 480-965-7671 (SHESC), 480-727-0709 (CSDC)
>>>>>> www: http://www.public.asu.edu/~cmbarton, http://csdc.asu.edu
>>>>>> <http://csdc.asu.edu/>
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> _______________________________________________
>>>>>> grass-user mailing list
>>>>>> grass-user at lists.osgeo.org <mailto:grass-user at lists.osgeo.org>
>>>>>> http://lists.osgeo.org/mailman/listinfo/grass-user
>>>>> 
>>>> 
>>> 
>> 
> 
> -- 
> Jennifer Boehnert
> GIS Coordinator
> National Center of Atmospheric Research
> PO Box 3000
> Boulder, CO, 80307