#382 proj4

nansat/mappers/mapper_opendap_mywave.py

@@ -0,0 +1,34 @@
+from nansat.mappers.opendap import Opendap
+from nansat.exceptions import WrongMapperError
+from nansat.nsr import NSR
+from netCDF4 import Dataset
+
+
+class Mapper(Opendap):
+
+    baseURLs = ['http://thredds.met.no/thredds/dodsC/fou-hi/mywavewam4archive']
+    timeVarName = 'time'
+    xName = 'rlon'
+    yName = 'rlat'
+    timeCalendarStart = '1970-01-01'
+
+    def __init__(self, filename, gdal_dataset, gdal_metadata, date=None,
+                 ds=None, bands=None, cachedir=None, *args, **kwargs):
+
+        self.test_mapper(filename)
+        # timestamp = date if date else self.get_date(filename)
+        ds = Dataset(filename)
+        proj4_str = Mapper.assemble_proj4_str(ds.variables['projection_3'])
+        try:
+            self.srcDSProjection = NSR(proj4_str)
+        except KeyError:
+            raise WrongMapperError
+
+    @staticmethod
+    def assemble_proj4_str(ds_proj_var):
+        """ Generate a GDAL accepted proj4 string """
+        proj4_pattern = "+proj=ob_tran +o_proj=longlat +lon_0=%s +o_lat_p=%s +a=6367470 " \
+                        "+b=6367470 +to_meter=0.0174532925199 +wktext"
+        ds_proj = proj4_pattern % (ds_proj_var.grid_north_pole_longitude - 180,
+                                   ds_proj_var.grid_north_pole_latitude)
+        return ds_proj