[gdal-dev] WRF NetCDF import
Lee Eddington
lee.w.eddington at gmail.com
Mon Nov 25 14:00:41 PST 2013
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
>>>
>>
>>
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>
>
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