[gdal-dev] Dateline gap

Jerl Simpson jsimpson at wxtrends.com
Thu Apr 14 09:18:30 EDT 2011


Joaquim:

Ok that makes more sense now.  You answered some of the questions I
was having, like how can ps2raster do anything with a necdf anyway?

I just used the info for that one test file, because the contents were
shorted.

It happens with others as well like this one that has these coordinates:
Corner Coordinates:
Upper Left  (-180.2500000,  90.2500000)
Lower Left  (-180.2500000, -90.2500000)
Upper Right ( 180.2500000,  90.2500000)
Lower Right ( 180.2500000, -90.2500000)
Center      (   0.0000000,   0.0000000)

I'll post questions on the GMT list as well.

Thanks

Jerl

On Thu, Apr 14, 2011 at 8:06 AM, Joaquim Luis <jluis at ualg.pt> wrote:
> Jerl,
>
> I suggested the ps2raster way because it's one that I know well (I'm
> supposed to) but probably there is also a GDAL solution (that I don't know).
> Since ps2raster is a GMT program I suggest that you make this questions in
> the GMT list. However, since I kind of start this I'll give some further
> infos here.
> Regarding the error message you got the explanation is simple. ps2raster
> takes a POSTSCRIPT file and converts it into other formats using ghoscript.
> If the ps file was created by GMT, it will detect the projection information
> stored as PS comments and use it to create a kml file (or geotiff btw). That
> means in principle ANY figure created with GMT and using plain geographical
> coordinates can be converted to KML. But you used ps2raster directly with
> the netcdf file, which is not possible at all. Finally, the netcdf file is a
> bit strange too. What are the coordinates?
> 0 512
> 0 512
> doesn't sound like real coordinates.
>
> Joaquim
>
>> Hello:
>>
>> I'm having a hard time getting anything to work with the files I have.
>>  Maybe the files need to be changed or translated?  Joaquim mentioned
>> they need to be in geogs but I'm not sure how to go about checking for
>> that or converting to that if need be.  I've included output from one
>> of the tests I ran.  It works the same way with all my files no matter
>> what the data inside is.  One thing I thought was strange was that I
>> used the -A option, and in the error message it tells me to use the -A
>> options.
>>
>> Command:
>> ps2raster -A -D./tests -E720 -TG -V -W+k testNETCDF.nc
>>
>> Output:
>> ps2raster: Processing testNETCDF.nc: Find HiResBoundingBox Error:
>> /undefined in CDF
>> Operand stack:
>>
>> Execution stack:
>>    %interp_exit   .runexec2   --nostringval--   --nostringval--
>> --nostringval--   2   %stopped_push   --nostringval--
>> --nostringval--   --nostringval--   false   1   %stopped_push   1878
>> 1   3   %oparray_pop   1877   1   3   %oparray_pop   1861   1   3
>> %oparray_pop   1755   1   3   %oparray_pop   --nostringval--
>> %errorexec_pop   .runexec2   --nostringval--   --nostringval--
>> --nostringval--   2   %stopped_push   --nostringval--
>> Dictionary stack:
>>    --dict:1151/1684(ro)(G)--   --dict:0/20(G)--   --dict:70/200(L)--
>> Current allocation mode is local
>> Current file position is 5
>> ps2raster: GMT FATAL ERROR: The file testNETCDF.nc has no BoundingBox
>> in the first 20 lines or last 256 bytes. Use -A option.
>>
>>
>> gdalinfo for netcdf:
>> Driver: netCDF/Network Common Data Format
>> Files: testNETCDF.nc
>> Size is 512, 512
>> Coordinate System is `'
>> Metadata:
>>   NC_GLOBAL#Conventions=COARDS
>>   NC_GLOBAL#calendar=standard
>>   NC_GLOBAL#comments=File
>>   NC_GLOBAL#model=geos/das
>>   NC_GLOBAL#center=gsfc
>> Subdatasets:
>>   SUBDATASET_1_NAME=NETCDF:"testNETCDF.nc":max_temp
>>   SUBDATASET_1_DESC=[15x601x1201] max_temp (32-bit floating-point)
>>   SUBDATASET_2_NAME=NETCDF:"testNETCDF.nc":min_temp
>>   SUBDATASET_2_DESC=[15x601x1201] min_temp (32-bit floating-point)
>>   SUBDATASET_3_NAME=NETCDF:"testNETCDF.nc":prcp
>>   SUBDATASET_3_DESC=[15x601x1201] prcp (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)
>>
>> Thank you,
>>
>> Jerl
>>
>> On Tue, Apr 12, 2011 at 7:24 PM, Joaquim Luis<jluis at ualg.pt>  wrote:
>>>
>>> Jerl,
>>>
>>> I would do that with GMT. By using ps2raster you can convert any GMT
>>> figure
>>> (in geogs of course) into KML, and GMT has excellent care of date line
>>> transition issues.
>>>
>>> Joaquim
>>>
>>>> Hello:
>>>>
>>>> I stopped by the #gdal channel on IRC to ask this question.  Thank you
>>>> for the help provided there.  I thought it might be better if I asked
>>>> a question here so I can better explain what's going on in one spot
>>>> and not flood the channel.
>>>> I understand this is a pixel center vs pixel edge issue.
>>>>
>>>> My ultimate goal is to get from a netCDF file to a google map overlay
>>>> contour.
>>>> The general steps I've taken, which work all the way up to about
>>>> 178.29 then it just cuts off.
>>>>
>>>> netCDF ->    color-relief PNG using "gdaldem color-relief ...  "
>>>> PNG ->    Geocoded PNG using "gdal_translate -a_srs EPSG:4326 -outsize
>>>> 4096 4096 -a_ullr -180.25 90.25 180.25 -90.25" on the PNG (Have also
>>>> tried this with just "-180 90 180 -90"
>>>> PNG ->    tiles using "gdal2tiles.py -s EPSG:4326 -z 0 -n -w google" on
>>>> the Geocoded PNG
>>>> I guess first question, is my methodology sound?  Maybe there's a
>>>> better way/tool to approach the problem.
>>>>
>>>> Following is the output from gdalinfo, other than that, what
>>>> information might I be able to provide that could help?
>>>>
>>>> Thank you,
>>>>
>>>> Jerl
>>>>
>>>> gdalinfo for the source netcdf: (My apologies, I'm not certain what is
>>>> relevant so I'm including most everything.)
>>>>
>>>> Driver: netCDF/Network Common Data Format
>>>> Files: test.nc
>>>> Size is 721, 361
>>>> Coordinate System is `'
>>>> Origin = (-180.250000000000000,90.250000000000000)
>>>> Pixel Size = (0.500000000000000,-0.500000000000000)
>>>> Metadata:
>>>>   NC_GLOBAL#Conventions=CF-1.0
>>>>   NC_GLOBAL#cdm_data_type=GRID
>>>>   NC_GLOBAL#file_format=GEMPAK
>>>>   NC_GLOBAL#location=test.grd
>>>>   NC_GLOBAL#history=Direct read of GEMPAK into NetCDF-Java 4.0 API
>>>>   NC_GLOBAL#_CoordinateModelRunDate=2011-04-12T00:00:00Z
>>>>   UVIN_NONE#long_name=testdata
>>>>   UVIN_NONE#units=
>>>>   UVIN_NONE#missing_value=-9.999000e+03
>>>>   UVIN_NONE#VectorComponentFlag=gridRelative
>>>>   time#long_name=forecast time
>>>>   time#units=minute since 2011-04-12T00:00:00Z
>>>>   time#_CoordinateAxisType=Time
>>>>   lat#units=degrees_north
>>>>   lat#long_name=latitude coordinate
>>>>   lat#standard_name=latitude
>>>>   lat#grid_spacing=0.5 degrees_north
>>>>   lat#_CoordinateAxisType=Lat
>>>>   lon#units=degrees_east
>>>>   lon#long_name=longitude coordinate
>>>>   lon#standard_name=longitude
>>>>   lon#grid_spacing=0.5 degrees_east
>>>>   lon#_CoordinateAxisType=Lon
>>>> Corner Coordinates:
>>>> Upper Left  (-180.2500000,  90.2500000)
>>>> Lower Left  (-180.2500000, -90.2500000)
>>>> Upper Right ( 180.2500000,  90.2500000)
>>>> Lower Right ( 180.2500000, -90.2500000)
>>>> Center      (   0.0000000,   0.0000000)
>>>>
>>>> gdalinfo of geocoded PNG:
>>>>
>>>> Driver: PNG/Portable Network Graphics
>>>> Files: testWorld.png
>>>>        testWorld.png.aux.xml
>>>> Size is 4096, 4096
>>>> Coordinate System is:
>>>> GEOGCS["WGS 84",
>>>>     DATUM["WGS_1984",
>>>>         SPHEROID["WGS 84",6378137,298.257223563,
>>>>             AUTHORITY["EPSG","7030"]],
>>>>         AUTHORITY["EPSG","6326"]],
>>>>     PRIMEM["Greenwich",0,
>>>>         AUTHORITY["EPSG","8901"]],
>>>>     UNIT["degree",0.01745329251994328,
>>>>         AUTHORITY["EPSG","9122"]],
>>>>     AUTHORITY["EPSG","4326"]]
>>>> Origin = (-180.000000000000000,90.000000000000000)
>>>> Pixel Size = (0.087890625000000,-0.043945312500000)
>>>> Image Structure Metadata:
>>>>   INTERLEAVE=PIXEL
>>>> Corner Coordinates:
>>>> Upper Left  (-180.0000000,  90.0000000) (180d 0'0.00"W, 90d 0'0.00"N)
>>>> Lower Left  (-180.0000000, -90.0000000) (180d 0'0.00"W, 90d 0'0.00"S)
>>>> Upper Right ( 180.0000000,  90.0000000) (180d 0'0.00"E, 90d 0'0.00"N)
>>>> Lower Right ( 180.0000000, -90.0000000) (180d 0'0.00"E, 90d 0'0.00"S)
>>>> Center      (   0.0000000,   0.0000000) (  0d 0'0.01"E,  0d 0'0.01"N)
>>>> Band 1 Block=4096x1 Type=Byte, ColorInterp=Red
>>>>   Mask Flags: PER_DATASET ALPHA
>>>> Band 2 Block=4096x1 Type=Byte, ColorInterp=Green
>>>>   Mask Flags: PER_DATASET ALPHA
>>>> Band 3 Block=4096x1 Type=Byte, ColorInterp=Blue
>>>>   Mask Flags: PER_DATASET ALPHA
>>>> Band 4 Block=4096x1 Type=Byte, ColorInterp=Alpha
>>>>
>>>>
>>>>
>>>
>>
>>
>
>



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