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[netCDFDecoders #GVS-648293]: AW: Grib2-Data from the german weather service

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  • Subject: [netCDFDecoders #GVS-648293]: AW: Grib2-Data from the german weather service
  • Date: Fri, 16 Jul 2010 17:26:48 -0600
Hi Katja,

The Rotated Lat/Lon code was obtained from a 3rd party

* Grib 1 projection 10 and Grib 2 projection 1.
 * The Rotated Latitude Longitude projection algorithms that are coded
 * here were given by Tor Christian Bekkvik <address@hidden>. The rotated
 * lat/lon projection coordinates that are in the grid file 
 * need to be converted back to un-rotated lat/lon projection coordinates
 * before they can be displayed. The X/Y axis only make sense in the rotated
 * projection.

The example parameters I'm comparing are:
 Rotatedlatlon

   char Rotated_Latitude_Longitude;
     :grid_mapping_name = "rotated_lat_lon";
     :grid_south_pole_latitude = -25.0; // double
     :grid_south_pole_longitude = 0.0; // double
     :grid_south_pole_angle = 0.0; // double
     :earth_shape = "spherical";
     :earth_radius = 6367.47021484375; // double
     :GRIB_param_Dx = 0.2; // double
     :GRIB_param_Dy = 0.2; // double
     :GRIB_param_GDSkey = -1602825218; // int
     :GRIB_param_La1 = -36.5; // double
     :GRIB_param_La2 = 38.9; // double
     :GRIB_param_Lo1 = -46.5; // double
     :GRIB_param_Lo2 = 46.9; // double
     :GRIB_param_Nx = 468; // int
     :GRIB_param_Ny = 378; // int
     :GRIB_param_ResCompFlag = 136; // int
     :GRIB_param_RotationAngle = 0.0; // double
     :GRIB_param_SpLat = -25.0; // double
     :GRIB_param_SpLon = 0.0; // double
     :GRIB_param_VectorComponentFlag = "gridRelative";
     :GRIB_param_Winds = "Relative";
     :GRIB_param_grid_name = "Rotated_Latitude_Longitude";
     :GRIB_param_grid_radius_spherical_earth = 6367.47; // double
     :GRIB_param_grid_shape = "spherical";
     :GRIB_param_grid_shape_code = 0; // int
     :GRIB_param_grid_type = 10; // int
     :GRIB_param_grid_units = "degrees";
     :GRIB_param_scanning_mode = 64; // int



COSMO_EU

   char Rotated_Latitude_Longitude;
     :grid_mapping_name = "rotated_lat_lon";
     :grid_south_pole_latitude = -40.0; // double
     :grid_south_pole_longitude = 10.0; // double
     :grid_south_pole_angle = 0.0; // double
     :earth_shape = "Earth spherical with radius of 6,371,229.0 m";
     :earth_radius = 6371229.0; // double
     :GRIB_param_Dx = 0.0625; // double
     :GRIB_param_Dy = 0.0625; // double
     :GRIB_param_GDSkey = 47803536; // int
     :GRIB_param_La1 = -20.0; // double
     :GRIB_param_La2 = 21.0; // double
     :GRIB_param_Lo1 = 342.0; // double
     :GRIB_param_Lo2 = 23.5; // double
     :GRIB_param_Nx = 665; // int
     :GRIB_param_Ny = 657; // int
     :GRIB_param_Quasi = "false";
     :GRIB_param_ResCompFlag = 56; // int
     :GRIB_param_RotationAngle = 0.0; // double
     :GRIB_param_SpLat = -40.0; // double
     :GRIB_param_SpLon = 10.0; // double
     :GRIB_param_VectorComponentFlag = "gridRelative";
     :GRIB_param_Winds = "Relative";
     :GRIB_param_grid_name = "Rotated_Latitude_Longitude";
     :GRIB_param_grid_radius_spherical_earth = 6371229.0; // double
     :GRIB_param_grid_shape = "Earth spherical with radius of 6,371,229.0 m";
     :GRIB_param_grid_shape_code = 6; // int
     :GRIB_param_grid_type = 1; // int
     :GRIB_param_grid_units = "degrees";
     :GRIB_param_scanning_mode = 64; // int


What do you think of these differences?  When the image is displayed from your 
test file, it's not on the projection at all.

Robb...

Ticket Details
===================
Ticket ID: GVS-648293
Department: Support netCDF Decoders
Priority: Normal
Status: Open