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Re: Fwd: Polar stereo projection parameter name problem

--1971325068-2114347592-1192724554=:29009
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Please disregard the last message, I miss interpreted the question because=
=20
the message was long and I assumed it was a parameter question.

Sorry,
Robb...





On Thu, 18 Oct 2007, Robb Kambic wrote:

> On Thu, 18 Oct 2007, Ben Domenico wrote:
>
>> Hi John and Robb,
>>=20
>> This is a follow up on an error in a variable name in a file served by t=
he
>> NCDC NOMADS TDS.  It turns out the source file is from ncep in grib.
>> Perhaps the GRIB iosp for these files is putting the wrong variable name=
 in
>> for the polar stereographic case.
>
>
> All,
>
> This is a GRIB table problem and it occurs because the desired table wasn=
't=20
> available, so the code uses the closes table available.
>
> dumping a radar file gives table info:
> center =3D 7
> sub_center =3D 4
> table_version =3D 2
>
> table used was:
>
> center =3D 7
> sub_center =3D -1   default sub_center table_version =3D 2
>
> The fix is to get table 7 4 2 and to include in the resources and make a=
=20
> release or if you don't want to change your release, then the table can b=
e=20
> added and referenced. This is a more time consuming process.
>
> Does anyone have table 7 4 2 in NWS format ?
>
> Once the correct table is added to the code, no modifications need to be =
done=20
> since Grib uses numbers internally so the parameters will be correct.
>
>
>
> Thanks,
> Robb...
>
>
>
> The THREDDS catalog for such datasets is
>> at:
>>=20
>>=20
>> http://nomads.ncdc.noaa.gov:8085/thredds/catalogServices?catalog=3Dhttp:=
//nomads.ncdc.noaa.gov:8085/thredds/catalog/radar/StIV/2006/catalog.xml
>>=20
>> The NCDC folks are talking about using ncML to correct the problem, but =
it
>> could be that the grib iosp is putting the wrong name in.  I thought thi=
s
>> was worth checking because, if it is the iosp, it will pop up on any TDS
>> that serves grib files in polar stereographic.
>>=20
>> -- Ben
>>=20
>> ---------- Forwarded message ----------
>> From: Steve.Ansari <address@hidden>
>> Date: Oct 18, 2007 7:09 AM
>> Subject: Re: Polar stereo projection parameter name problem
>> To: "Glenn.Rutledge" <address@hidden>
>> Cc: Ben Domenico <address@hidden>, John Caron=20
>> <address@hidden>,
>> Nomads NCDC <address@hidden>, Brian Nelson <address@hidden>=
,
>> Rich Baldwin <address@hidden>
>>=20
>> Hello all,
>>=20
>> The STIV (Stage-4 Multisensor Precip from NCEP) are in GRIB files from
>> NCEP.
>>=20
>> John,
>> Is this a parameter that should be different in the GRIB file?  Can we u=
se
>> NcML to describe an 'alias' for this parameter?  If so, can you send a
>> sample.
>>=20
>> Thanks,
>> Steve
>>=20
>>=20
>>=20
>> Glenn.Rutledge said the following on 10/18/2007 8:24 AM:
>>=20
>> Hi Ben,
>> This server data is populated and maintained (mostly) by Steve Ansari an=
d
>> Brian Nelson.  They are cc;ed to this and I'm certain they'll look into =
it.
>>=20
>>=20
>> It turns out that this data, and some others (GOES),k and projected grid=
s
>> have some " incompatibility" issues for their datum description while be=
ing
>> access with the GeoPortal Tooklit by ESRI (aka our ACCESS conversions of
>> late)- as reported by Rich Baldwin here and he's also cc:ed just in case
>> this might be germane.
>>=20
>> Regards, Glenn
>>=20
>> Ben Domenico wrote the following on 10/17/2007 3:36 PM:
>>=20
>> Hi Glenn,
>>=20
>> You may not be the right person for this note, but I'll start with you w=
ith
>> the idea you can forward it to the appropriate person.  As the note belo=
w
>> from John Caron indicates, there is a problem with the name being used t=
o
>> specify the latitude coordinate for the polar stereographic coordinate
>> system being used to serve STIV radar data on the nomads server.  The
>> prescribed CF name is "straight_vertical_longitude_from_pole"  but the
>> netCDF file uses "longitude_of_projection_origin."  According to John, t=
his
>> is not an uncommon error, but it would be good to fix it.
>>=20
>> Thanks.
>>=20
>> -- Ben
>>=20
>> ---------- Forwarded message ----------
>> From: John Caron <address@hidden >
>> Date: Oct 17, 2007 1:08 PM
>> Subject: Re: attached file
>> To: Ben Domenico <address@hidden>
>> Cc: Nawajish Noman <address@hidden >, address@hidden.=
edu
>>=20
>> Hi Noman:
>>=20
>> Unfortunately its common for these files to not follow the conventions
>> exactly.
>>=20
>> "longitude_of_projection_origin" should be
>> "straight_vertical_longitude_from_pole". Its a common error, and we tend=
 to
>> try to be lenient in these cases, so our software would probably look fo=
r
>> both names.
>>=20
>> Ben, can we notify the writer? Also, can I get a sample of the file for =
my
>> tests?
>>=20
>> John
>>=20
>> Ben Domenico wrote:
>>> Noman,
>>>=20
>>> I'm forwarding this message to John Caron who can help you with the
>>> details of the projection in that netCDF file.
>>>=20
>>> -- Ben
>>>=20
>>> On 10/16/07, * Nawajish Noman* <address@hidden
>>> <mailto: address@hidden>> wrote:
>>>
>>>     Hi Ben,
>>>
>>>     We are working on the problem with Polar stereographic projection. =
I
>>>     am comparing the grid_mapping parameters in the file (see your emai=
l
>>>     below) and the parameters listed on the CF Convention page at _
>>>     http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.0/cf-convention=
s.html#appendix-grid-mappings_
>>
>>>     Example F.5.
>>>
>>>     *Example F.5. Polar stereographic*
>>>
>>>     grid_mapping_name =3D polar_stereographic
>>>=20
>>>=20
>>>
>>>     */Map parameters:/*
>>>
>>>     straight_vertical_longitude_from_pole
>>>
>>>     latitude_of_projection_origin - Either +90. or -90.
>>>
>>>     Either standard_parallel or scale_factor_at_projection_origin
>>>
>>>     false_easting
>>>
>>>     false_northing
>>>
>>>     *Parameters in file are:***
>>>
>>>     char Polar_Stereographic_projection_Grid;
>>>
>>>          :grid_mapping_name =3D "polar_stereographic";
>>>
>>>          :longitude_of_projection_origin =3D - 105.0; // double
>>>
>>>          :scale_factor_at_projection_origin =3D 0.933; // double
>>>
>>>     Here are my questions:
>>>
>>>     Q1: Some of the parameters are missing in file. What do we do about
>>>     missing parameters?
>>>
>>>     Q2: You have " longitude_of_projection_origin " in file but the CF
>>>     convention says " latitude_of_projection_origin" - What do with
>>>     "longitude_of_projection_origin "?
>>>
>>>     We look for parameters listed in CF Conventions and map them to our
>>>     Spatial reference parameters. If parameters are missing in file we
>>>     assume default value. If incorrect parameters are specified - we
>>>     ignore them.
>>>
>>>     I want to make sure we are reading the parameters from your file
>>>     correctly. Please comment=85
>>>
>>>     Thanks,
>>>
>>>     Noman
>>>
>>>     -----Original Message-----
>>>     From: address@hidden <mailto:address@hidden> [
>>>     mailto: address@hidden] On Behalf Of Ben Domenico
>>>     Sent: Tuesday, June 05, 2007 1:56 PM
>>>     To: Steve Kopp
>>>     Cc: Nawajish Noman
>>>     Subject: Re: attached file
>>>
>>>     Steve,
>>>
>>>     I'll attach jpegs of the dataset as displayed in arcMap and one fro=
m
>>>
>>>     the IDV.  In each case, you can see at the bottom of the screen, th=
e
>>>
>>>     lat/lon values associated with the cursor position.  I'll also appe=
nd
>>>
>>>     the ncDump output which shows the projection information -- in netC=
DF
>>>
>>>     terms (i.e., Polar_Stereographic_projection_Grid) anyway.
>>>
>>>     -- Ben
>>>
>>>     ncDump output
>>>
>>>     =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D
>>>
>>>     netcdf C:/Documents and
>>>     Settings/ben/Desktop/ST4.2006010100.06hWithLatLon.nc {
>>>
>>>      dimensions:
>>>
>>>        time =3D 1;   // (has coord.var)
>>>
>>>        y =3D 815;   // (has coord.var)
>>>
>>>        x =3D 1121;   // (has coord.var)
>>>
>>>      variables:
>>>
>>>        float Total_precipitation(time=3D1, y=3D815, x=3D1121);
>>>
>>>          :units =3D "kg/m^2";
>>>
>>>          :long_name =3D "Total precipitation @ surface";
>>>
>>>          :missing_value =3D -9999.0f; // float
>>>
>>>          :grid_mapping =3D "Polar_Stereographic_projection_Grid";
>>>
>>>          :GRIB_param_name =3D "Total precipitation";
>>>
>>>          :GRIB_center_id =3D 7; // int
>>>
>>>          :GRIB_table_id =3D 2; // int
>>>
>>>          :GRIB_param_number =3D 61; // int
>>>
>>>          :GRIB_param_id =3D 1, 7, 2, 61; // int
>>>
>>>          :GRIB_product_definition_type =3D "Accumulation";
>>>
>>>          :GRIB_level_type =3D 1; // int
>>>
>>>        int time(time=3D1);
>>>
>>>          :long_name =3D "forecast time";
>>>
>>>          :units =3D "hour since 2005-12-31T12:00:00Z";
>>>
>>>          :GRIB_orgReferenceTime =3D "2005-12-31T12:00:00Z";
>>>
>>>          :GRIB2_significanceOfRTName =3D "Start of forecast";
>>>
>>>          :_CoordinateAxisType =3D "Time";
>>>
>>>        double y(y=3D815);
>>>
>>>          :units =3D "km";
>>>
>>>          :long_name =3D "y coordinate of projection";
>>>
>>>          :standard_name =3D "projection_y_coordinate";
>>>
>>>          :grid_spacing =3D "4.763 km";
>>>
>>>          :_CoordinateAxisType =3D "GeoY";
>>>
>>>        double x(x=3D1121);
>>>
>>>          :units =3D "km";
>>>
>>>          :long_name =3D "x coordinate of projection";
>>>
>>>          :standard_name =3D "projection_x_coordinate";
>>>
>>>          :grid_spacing =3D "4.763 km";
>>>
>>>          :_CoordinateAxisType =3D "GeoX";
>>>
>>>        char Polar_Stereographic_projection_Grid;
>>>
>>>          :grid_mapping_name =3D "polar_stereographic";
>>>
>>>          :longitude_of_projection_origin =3D -105.0; // double
>>>
>>>          :scale_factor_at_projection_origin =3D 0.933 ; // double
>>>
>>>          :earth_shape =3D "spherical";
>>>
>>>          :GRIB_param_Dx =3D 4763.0; // double
>>>
>>>          :GRIB_param_Dy =3D 4763.0; // double
>>>
>>>          :GRIB_param_GDSkey =3D 1294122487; // int
>>>
>>>          :GRIB_param_La1 =3D 23.117; // double
>>>
>>>          :GRIB_param_Lo1 =3D -119.023; // double
>>>
>>>          :GRIB_param_LoV =3D -105.0; // double
>>>
>>>          :GRIB_param_Nx =3D 1121; // int
>>>
>>>          :GRIB_param_Ny =3D 881; // int
>>>
>>>          :GRIB_param_ProjFlag =3D 0; // int
>>>
>>>          :GRIB_param_ResCompFlag =3D 8; // int
>>>
>>>          :GRIB_param_ScanningMode =3D 64; // int
>>>
>>>          :GRIB_param_grid_name =3D "Polar Stereographic projection Grid=
";
>>>
>>>          :GRIB_param_grid_radius_spherical_earth =3D 6367.47; // double
>>>
>>>          :GRIB_param_grid_shape =3D "spherical";
>>>
>>>          :GRIB_param_grid_shape_code =3D 0; // int
>>>
>>>          :GRIB_param_grid_type =3D 5; // int
>>>
>>>          :_CoordinateTransformType =3D "Projection";
>>>
>>>          :_CoordinateAxisTypes =3D "GeoX GeoY";
>>>
>>>        double lat(y=3D815, x=3D1121);
>>>
>>>          :units =3D "degrees_north";
>>>
>>>          :long_name =3D "latitude coordinate";
>>>
>>>          :standard_name =3D "latitude";
>>>
>>>          :_CoordinateAxisType =3D "Lat";
>>>
>>>        double lon(y=3D815, x=3D1121);
>>>
>>>          :units =3D "degrees_east";
>>>
>>>          :long_name =3D "longitude coordinate";
>>>
>>>          :standard_name =3D "longitude";
>>>
>>>          :_CoordinateAxisType =3D "Lon";
>>>
>>>      :History =3D "GridDatatype extracted from dataset
>>>
>>>     /eclipse1a/ftp/pub/radar/StIV/2006/01/01/hr/ST4.2006010100.06h";
>>>
>>>      :Conventions =3D "CF-1.0";
>>>
>>>      :Originating_center =3D "US National Weather Service (NCEP) subcen=
ter
>>>     =3D 4";
>>>
>>>      :Generating_Process_or_Model =3D "River Forecast Center Quantitati=
ve
>>>
>>>     Precipitation estimate mosaic generated by NCEP";
>>>
>>>      :Product_Type =3D "Accumulation";
>>>
>>>      :cdm_data_type =3D "Grid";
>>>
>>>      :creator_name =3D "US National Weather Service (NCEP) subcenter =
=3D 4";
>>>
>>>      :file_format =3D "GRIB-1";
>>>
>>>      :location =3D
>>>     "/eclipse1a/ftp/pub/radar/StIV/2006/01/01/hr/ST4.2006010100.06h";
>>>
>>>      :history =3D "Direct read of GRIB into NetCDF-Java 2.2 API";
>>>
>>>      :_CoordinateModelRunDate =3D "2005-12-31T12:00:00Z";
>>>
>>>     =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D
>>>
>>>     On 6/5/07, Steve Kopp < address@hidden <mailto:address@hidden>> wro=
te:
>>>
>>>    >
>>>
>>>    >  Ben, the dataset contains no projection information. Without this=
,
>> we
>>>
>>>    >  won't know where else to draw anything.
>>>
>>>    >
>>>
>>>    >  Could you send us a screen shot of what you are seeing?
>>>
>>>    >
>>>
>>>    >  Thanks,
>>>
>>>    >
>>>
>>>    >  Steve
>>>
>>>    >
>>>
>>>    >
>>>
>>>    >  -----Original Message-----
>>>
>>>    >  From: address@hidden <mailto:address@hidden> [
>>>     mailto:address@hidden] On Behalf Of
>>>
>>>    >  Ben Domenico
>>>
>>>    >  Sent: Tuesday, June 05, 2007 11:32 AM
>>>
>>>    >  To: Steve Kopp
>>>
>>>    >  Subject: attached file
>>>
>>>    >
>>>
>>>    >  Hi Steve,
>>>
>>>    >
>>>
>>>    >  Don't know if this will work, but I'm attaching one of the
>> CF-netCDF
>>>
>>>    >  files I got from that NCDC radar data server.  Let me know whethe=
r
>>>
>>>    >  this comes through OK.
>>>
>>>    >
>>>
>>>    >  -- Ben
>>>
>>>    >
>>>
>>>    >
>>>=20
>>>=20
>>=20
>>=20
>> --=20
>> Glenn K. Rutledge
>> Services Team Leader
>> Remote Sensing and Applications Division
>> NOMADS Project Manager
>> National Oceanic and Atmospheric Administration
>> National Climatic Data Center
>> Asheville NC 28801
>> Phone: (828) 271-4097
>> Fax: (828) 271-4328
>>=20
>> NOMADS: http://nomads.ncdc.noaa.gov/
>>=20
>>=20
>> --=20
>> Steve Ansari
>> Physical Scientist
>> NOAA's National Climatic Data Center
>> Veach-Baley Federal Building
>> 151 Patton Avenue
>> Asheville, NC 28801
>> Ph: 828-271-4611
>> Fax: 828-271-4022
>>=20
>
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D
> Robb Kambic        =09=09=09   Unidata Program Center
> Software Engineer III=09=09=09   Univ. Corp for Atmospheric=20
> Research
> address@hidden=09=09   WWW: http://www.unidata.ucar.edu/
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D
Robb Kambic        =09=09=09   Unidata Program Center
Software Engineer III=09=09=09   Univ. Corp for Atmospheric Research
address@hidden=09=09   WWW: http://www.unidata.ucar.edu/
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D
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