Define raster Rotation in NetCDF

Question

I am trying to add rotation to a NetCDF File

One Idea was to add a additional parameter to my current grid mapping that describes the rotation point and the rotation:

PROJCS["Hotine_Oblique_Mercator_Azimuth_Center", 
  GEOGCS["GCS_WGS_1984", 
    DATUM["D_unknown", 
      SPHEROID["WGS84", 6378137.0, 298.257223563]], 
    PRIMEM["Greenwich", 0.0], 
    UNIT["degree", 0.017453292519943295], 
    AXIS["Longitude", EAST], 
    AXIS["Latitude", NORTH]], 
  PROJECTION["Oblique_Mercator"], 
  PARAMETER["longitude_of_center", 7.0], 
  PARAMETER["latitude_of_center", 51.4], 
  PARAMETER["azimuth", -10.0], 
  PARAMETER["scale_factor", 1.0], 
  PARAMETER["false_easting", 0.0], 
  PARAMETER["false_northing", 0.0], 
  PARAMETER["rectified_grid_angle", -10.0], 
  UNIT["m", 1.0], 
  AXIS["x", EAST], 
  AXIS["y", NORTH], 
  AUTHORITY["EPSG","8011112"]]

Another try with Affine Rotation:

FITTED_CS["BPAF", 
  PARAM_MT["Affine", 
    PARAMETER["num_row", 3], 
    PARAMETER["num_col", 3], 
    PARAMETER["elt_0_0", 0.16867854068466956], 
    PARAMETER["elt_0_1", -0.2699420929659323], 
    PARAMETER["elt_0_2", 918079.626281209], 
    PARAMETER["elt_1_0", 0.2699420929659323], 
    PARAMETER["elt_1_1", 0.16867854068466956], 
    PARAMETER["elt_1_2", 6445039.217828758]], 
  PROJCS["WGS84 / Google Mercator", 
    GEOGCS["WGS 84", 
      DATUM["World Geodetic System 1984", 
        SPHEROID["WGS 84", 6378137.0, 298.257223563, AUTHORITY["EPSG","7030"]], 
        AUTHORITY["EPSG","6326"]], 
      PRIMEM["Greenwich", 0.0, AUTHORITY["EPSG","8901"]], 
      UNIT["degree", 0.017453292519943295], 
      AXIS["Longitude", EAST], 
      AXIS["Latitude", NORTH], 
      AUTHORITY["EPSG","4326"]], 
    PROJECTION["Mercator_1SP"], 
    PARAMETER["semi_minor", 6378137.0], 
    PARAMETER["latitude_of_origin", 0.0], 
    PARAMETER["central_meridian", 0.0], 
    PARAMETER["scale_factor", 1.0], 
    PARAMETER["false_easting", 0.0], 
    PARAMETER["false_northing", 0.0], 
    UNIT["m", 1.0], 
    AXIS["x", EAST], 
    AXIS["y", NORTH], 
    AUTHORITY["EPSG","900913"]], 
  AUTHORITY["EPSG","8011113"]]

Another idea was to use two dimensional coordinates that are pointing directly to the georeferenced coordinates:

netcdf test {
dimensions:
        time = UNLIMITED ; // (3 currently)
        y = 10 ;
        x = 27 ;
        z = 2 ;
variables:
        double time(time) ;
                time:long_name = "time" ;
                time:units = "hours since 2018-06-23T05:00:00Z" ;
                time:calendar = "standard" ;
                time:axis = "T" ;
        double lat(y, x) ;
                lat:long_name = "latitude" ;
                lat:units = "degrees_north" ;
        double lon(y, x) ;
                lon:long_name = "longitude" ;
                lon:units = "degrees_east" ;
        double TSurf(time, y, x) ;
                TSurf:_FillValue = -999. ;
                TSurf:valid_min = -50.f ;
                TSurf:valid_max = 150.f ;
                TSurf:long_name = "Surface Temperature" ;
                TSurf:units = "degree Celsius" ;

// global attributes:
                :Conventions = "CF-1.7" ;
}

All three methods don't seem to work properly in QGis or Geoserver

Anyone has already some practice with NetCDF raster data that is not north up oriented?

Answer 1

fixed by editing the code from this topic: Using customized Coordinate System in ArcGIS Desktop?

My used grid_mapping:

def addGridMappingVars(var,locationLat,locationLon,rotation):
    var.grid_mapping_name= "mercator"
    var.standard_parallel= 0.0
    var._CoordinateTransformType= "Projection"
    var._CoordinateAxisTypes= "GeoX GeoY"
    var.spatial_ref= 'PROJCS["Hotine_Oblique_Mercator_Azimuth_Center",GEOGCS["GCS_WGS_1984",DATUM["D_unknown",SPHEROID["WGS84",6378137,298.257223563]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],PARAMETER["latitude_of_center",'+str(locationLat)+'],PARAMETER["longitude_of_center",'+str(locationLon)+'],PARAMETER["rectified_grid_angle",'+str(-rotation)+'],PARAMETER["scale_factor",1],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["m",1.0], AUTHORITY["EPSG","8011112"]]'
    return var