add helper method for getting cf geostationary nav projection parameters.

modules/util/geos_nav.py

@@ -266,6 +266,38 @@ def get_navigation(satellite='GOES16', domain='FD'):
     return nav
 
 
+def get_cf_nav_parameters(satellite='GOES16', domain='FD'):
+    param_dct = None
+
+    if satellite == 'H08':  # We presently only have FD
+        param_dct = {'semi_major_axis': 6378.137,
+                     'semi_minor_axis': 6356.7523,
+                     'perspective_point_height': 35785.863,
+                     'latitude_of_projection_origin': 0.0,
+                     'longitude_of_projection_origin': 140.7,
+                     'inverse_flattening': 298.257,
+                     'sweep_angle_axis': 'y',
+                     'x_scale_factor': 5.58879902955962e-05,
+                     'x_add_offset': -0.153719917308037,
+                     'y_scale_factor': -5.58879902955962e-05,
+                     'y_add_offset': 0.153719917308037}
+    elif satellite == 'GOES16':
+        if domain == 'CONUS':
+            param_dct = {'semi_major_axis': 6378137.0,
+                         'semi_minor_axis': 6356752.31414,
+                         'perspective_point_height': 35786023.0,
+                         'latitude_of_projection_origin': 0.0,
+                         'longitude_of_projection_origin': -75,
+                         'inverse_flattening': 298.257,
+                         'sweep_angle_axis': 'x',
+                         'x_scale_factor': 5.6E-05,
+                         'x_add_offset': -0.101332,
+                         'y_scale_factor': -5.6E-05,
+                         'y_add_offset': 0.128212}
+
+    return param_dct
+
+
 def get_lon_lat_2d_mesh(nav, ll, cc):
     num_elems = len(cc)
     num_lines = len(ll)