[gdal-dev] WRF NetCDF import

Lee Eddington lee.w.eddington at gmail.com
Mon Nov 25 20:27:54 PST 2013 

I think I might be getting close.  I found the following which I'm hoping
will create the GeoTiff with angular units of degrees instead of linear
units of meters:

OGRErr OGRSpatialReference::SetAngularUnits(const char * pszUnitsName,
double dfInRadians
)

and tried to use it, but don't know the proper pszUnitsName.  I've tried
"degree", "degrees", "DEGREE", "DEGREES", "DEG", "SRS_UA_DEGREE", but
always get a return code of 6 instead of 0.  I can't find a list of names
or any examples of how to use this properly.


On Mon, Nov 25, 2013 at 2:00 PM, Lee Eddington <lee.w.eddington at gmail.com>wrote:

> Roger,
>
> Thank you for the info and link.  Using a modified version of your code I
> was able to create and import into GRASS a GeoTIFF with the proper
> georeferencing.  The coordinate system units are in meters though, and I'd
> prefer to have them in degrees lat/lon.  Do you know if there's a way to
> specify that using the oar or gdal routines in your code?
>
> Thanks,
> Lee
>
>
>
> On Mon, Nov 25, 2013 at 10:23 AM, Etienne Tourigny <
> etourigny.dev at gmail.com> wrote:
>
>> Forwarding to the list and others...
>>
>> ---------- Forwarded message ----------
>> From: Roger Veciana i Rovira <rveciana at gmail.com>
>> Date: Mon, Nov 25, 2013 at 9:35 AM
>> Subject: Re: [gdal-dev] WRF NetCDF import
>> To: Etienne Tourigny <etourigny.dev at gmail.com>
>>
>>
>> As Etienne told you, the geotransform and projection from your files is
>> not in the format that GDAL can understand.
>> I wrote a script that reads the projection and calculates the
>> geotransform to save it in a GeoTIFF file:
>>
>>
>> http://geoexamples.blogspot.com.es/2013/09/reading-wrf-netcdf-files-with-gdal.html
>>
>> The script also interpolates the WRF sigma levels to the desired pressure
>> level, so you will have to look for the functions that you need.
>>
>> Anyway, the solution is quite complicated, and using cdo, nco or other
>> tools (I use ARWPost) may be easier.
>>
>> Roger
>>
>>
>> 2013/11/24 Etienne Tourigny <etourigny.dev at gmail.com>
>>
>>> The "georeferencing info" you refer to is non-standard, and GDAL cannot
>>> use that. It (and presumably the grass provider, although I don't know) use
>>> the CF standard for encoding lat/lon information. what is the output of
>>> gdalinfo NETCDF:test_full.nc:HGT
>>>
>>> I don't know how the grass provider deals with subdatasets, but if you
>>> open the file in qgis (using the gdal provider, it will sllow you to select
>>> the subdataset you want).
>>>
>>> You could also extract the variable with another tool like cdo or nco.
>>>
>>> Etienne
>>>
>>>
>>>
>>> On Sat, Nov 23, 2013 at 7:47 PM, Lee Eddington <
>>> lee.w.eddington at gmail.com> wrote:
>>>
>>>> I'm trying to use r.in.gdal in GRASS GIS to import Weather Research &
>>>> Forecasting (WRF) model NetCDF output.  There have been some tips provided
>>>> by the GRASS users list, but none have worked for me.  I can import the
>>>> data as a simple x,y array with no georeferencing, but information about
>>>> georeferencing is in the file as other programs read, georeference and
>>>> display the file correctly.
>>>>
>>>> gdalinfo produces the following:
>>>>
>>>> lees-mbp:full Lee$ gdalinfo test_full.nc
>>>> Warning 1: No UNIDATA NC_GLOBAL:Conventions attribute
>>>>  Driver: netCDF/Network Common Data Format
>>>> Files: test_full.nc
>>>> Size is 512, 512
>>>> Coordinate System is `'
>>>> Metadata:
>>>>   NC_GLOBAL#BL_PBL_PHYSICS=1
>>>>   NC_GLOBAL#BOTTOM-TOP_GRID_DIMENSION=28
>>>>   NC_GLOBAL#BOTTOM-TOP_PATCH_END_STAG=28
>>>>   NC_GLOBAL#BOTTOM-TOP_PATCH_END_UNSTAG=27
>>>>   NC_GLOBAL#BOTTOM-TOP_PATCH_START_STAG=1
>>>>   NC_GLOBAL#BOTTOM-TOP_PATCH_START_UNSTAG=1
>>>>   NC_GLOBAL#BUCKET_J=-1
>>>>   NC_GLOBAL#BUCKET_MM=-1
>>>>   NC_GLOBAL#CEN_LAT=-8.4095154
>>>>   NC_GLOBAL#CEN_LON=115.02
>>>>   NC_GLOBAL#CU_PHYSICS=0
>>>>   NC_GLOBAL#DAMP_OPT=0
>>>>   NC_GLOBAL#DAMPCOEF=0.2
>>>>   NC_GLOBAL#DFI_OPT=0
>>>>   NC_GLOBAL#DIFF_6TH_FACTOR=0.12
>>>>   NC_GLOBAL#DIFF_6TH_OPT=0
>>>>   NC_GLOBAL#DIFF_OPT=1
>>>>   NC_GLOBAL#DT=16.666666
>>>>   NC_GLOBAL#DX=3000
>>>>   NC_GLOBAL#DY=3000
>>>>   NC_GLOBAL#FEEDBACK=0
>>>>   NC_GLOBAL#GFDDA_END_H=0
>>>>   NC_GLOBAL#GFDDA_INTERVAL_M=0
>>>>   NC_GLOBAL#GMT=12
>>>>   NC_GLOBAL#GRID_FDDA=0
>>>>   NC_GLOBAL#GRID_ID=3
>>>>   NC_GLOBAL#GRID_SFDDA=0
>>>>   NC_GLOBAL#GRIDTYPE=C
>>>>   NC_GLOBAL#HYPSOMETRIC_OPT=2
>>>>   NC_GLOBAL#I_PARENT_START=34
>>>>   NC_GLOBAL#ISFTCFLX=0
>>>>   NC_GLOBAL#ISHALLOW=0
>>>>   NC_GLOBAL#ISICE=24
>>>>   NC_GLOBAL#ISLAKE=-1
>>>>   NC_GLOBAL#ISOILWATER=14
>>>>   NC_GLOBAL#ISURBAN=1
>>>>   NC_GLOBAL#ISWATER=16
>>>>   NC_GLOBAL#J_PARENT_START=34
>>>>   NC_GLOBAL#JULDAY=324
>>>>   NC_GLOBAL#JULYR=2013
>>>>   NC_GLOBAL#KHDIF=0
>>>>   NC_GLOBAL#KM_OPT=4
>>>>   NC_GLOBAL#KVDIF=0
>>>>   NC_GLOBAL#MAP_PROJ=3
>>>>   NC_GLOBAL#MFSHCONV=0
>>>>   NC_GLOBAL#MMINLU=USGS
>>>>   NC_GLOBAL#MOAD_CEN_LAT=-8.4095078
>>>>   NC_GLOBAL#MOIST_ADV_OPT=1
>>>>   NC_GLOBAL#MP_PHYSICS=3
>>>>   NC_GLOBAL#NUM_LAND_CAT=24
>>>>   NC_GLOBAL#OBS_NUDGE_OPT=0
>>>>   NC_GLOBAL#OMLCALL=0
>>>>   NC_GLOBAL#PARENT_GRID_RATIO=3
>>>>   NC_GLOBAL#PARENT_ID=2
>>>>   NC_GLOBAL#POLE_LAT=90
>>>>   NC_GLOBAL#POLE_LON=0
>>>>   NC_GLOBAL#PREC_ACC_DT=0
>>>>   NC_GLOBAL#RA_LW_PHYSICS=1
>>>>   NC_GLOBAL#RA_SW_PHYSICS=1
>>>>   NC_GLOBAL#SCALAR_ADV_OPT=1
>>>>   NC_GLOBAL#SF_SFCLAY_PHYSICS=1
>>>>   NC_GLOBAL#SF_SURFACE_PHYSICS=2
>>>>   NC_GLOBAL#SF_URBAN_PHYSICS=0
>>>>   NC_GLOBAL#SGFDDA_END_H=0
>>>>   NC_GLOBAL#SGFDDA_INTERVAL_M=0
>>>>   NC_GLOBAL#SHCU_PHYSICS=0
>>>>   NC_GLOBAL#SIMULATION_START_DATE=2013-11-20_12:00:00
>>>>   NC_GLOBAL#SMOOTH_OPTION=0
>>>>   NC_GLOBAL#SOUTH-NORTH_GRID_DIMENSION=154
>>>>   NC_GLOBAL#SOUTH-NORTH_PATCH_END_STAG=154
>>>>   NC_GLOBAL#SOUTH-NORTH_PATCH_END_UNSTAG=153
>>>>   NC_GLOBAL#SOUTH-NORTH_PATCH_START_STAG=1
>>>>   NC_GLOBAL#SOUTH-NORTH_PATCH_START_UNSTAG=1
>>>>   NC_GLOBAL#SST_UPDATE=0
>>>>   NC_GLOBAL#STAND_LON=115.02
>>>>   NC_GLOBAL#START_DATE=2013-11-20_12:00:00
>>>>   NC_GLOBAL#SURFACE_INPUT_SOURCE=1
>>>>   NC_GLOBAL#SWRAD_SCAT=1
>>>>   NC_GLOBAL#TITLE= OUTPUT FROM WRF V3.4 MODEL
>>>>   NC_GLOBAL#TKE_ADV_OPT=1
>>>>   NC_GLOBAL#TRUELAT1=-8.4095001
>>>>   NC_GLOBAL#TRUELAT2=0
>>>>   NC_GLOBAL#W_DAMPING=0
>>>>   NC_GLOBAL#WEST-EAST_GRID_DIMENSION=199
>>>>   NC_GLOBAL#WEST-EAST_PATCH_END_STAG=199
>>>>   NC_GLOBAL#WEST-EAST_PATCH_END_UNSTAG=198
>>>>   NC_GLOBAL#WEST-EAST_PATCH_START_STAG=1
>>>>   NC_GLOBAL#WEST-EAST_PATCH_START_UNSTAG=1
>>>> Subdatasets:
>>>>   SUBDATASET_1_NAME=NETCDF:"test_full.nc":Times
>>>>   SUBDATASET_1_DESC=[1x19] Times (8-bit character)
>>>>   SUBDATASET_2_NAME=NETCDF:"test_full.nc":LU_INDEX
>>>>   SUBDATASET_2_DESC=[1x153x198] LU_INDEX (32-bit floating-point)
>>>>
>>>> (more SUBDATASETs)
>>>>
>>>>   SUBDATASET_106_NAME=NETCDF:"test_full.nc":LANDMASK
>>>>   SUBDATASET_106_DESC=[1x153x198] LANDMASK (32-bit floating-point)
>>>>   SUBDATASET_107_NAME=NETCDF:"test_full.nc":SST
>>>>   SUBDATASET_107_DESC=[1x153x198] SST (32-bit floating-point)
>>>> Corner Coordinates:
>>>> Upper Left  (    0.0,    0.0)
>>>> Lower Left  (    0.0,  512.0)
>>>> Upper Right (  512.0,    0.0)
>>>> Lower Right (  512.0,  512.0)
>>>> Center      (  256.0,  256.0)
>>>>
>>>> My first question is why am I getting the following warning?:
>>>>
>>>> Warning 1: No UNIDATA NC_GLOBAL:Conventions attribute
>>>>
>>>> Next, I see what appears is georeferencing info in the following lines:
>>>>
>>>>   NC_GLOBAL#CEN_LAT=-8.4095154
>>>>   NC_GLOBAL#CEN_LON=115.02
>>>>   NC_GLOBAL#MAP_PROJ=3 (Mercator)
>>>>   NC_GLOBAL#MOAD_CEN_LAT=-8.4095078
>>>>    NC_GLOBAL#STAND_LON=115.02
>>>>   NC_GLOBAL#TRUELAT1=-8.4095001
>>>>
>>>> but obviously this is not being interpreted or used.
>>>>
>>>> Trying to use gdalwarp:
>>>>
>>>> lees-mbp:full Lee$ gdalwarp NETCDF:test_full.nc:HGT test_full_HGT.tif
>>>> Warning 1: No UNIDATA NC_GLOBAL:Conventions attribute
>>>> ERROR 1: Unable to compute a transformation between pixel/line
>>>> and georeferenced coordinates for NETCDF:test_full.nc:HGT.
>>>> There is no affine transformation and no GCPs.
>>>>
>>>> Can anyone explain what I need to do?
>>>>
>>>> Thanks,
>>>> Lee
>>>>
>>>>
>>>> _______________________________________________
>>>> gdal-dev mailing list
>>>> gdal-dev at lists.osgeo.org
>>>> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>>>>
>>>
>>>
>>> _______________________________________________
>>> gdal-dev mailing list
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>>>
>>
>>
>>
>
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