Plotting Radarsat-2 using Cartopy

Dear all

I want to plot some Radarsat-2 scenes using Cartopy. The problem I’m facing is that Cartopy does not accept epsg:4326 as a valid coordinate system.I managed to project the intensity values to my desired coordinates using the Ellipsoidal Correction tool in SNAP, but it doesn’t work for the polarimetric decompositions I made. Does anyone know a workaround? Is it possible to use the projection arguments provided by snap directly in Cartopy, e.g.:

PROJCS[“WGS 84 / EPSG Norway Polar Stereographic”,
DATUM[“World Geodetic System 1984”,
SPHEROID[“WGS 84”, 6378137.0, 298.257223563, AUTHORITY[“EPSG”,“7030”]],
PRIMEM[“Greenwich”, 0.0, AUTHORITY[“EPSG”,“8901”]],
UNIT[“degree”, 0.017453292519943295],
AXIS[“Geodetic longitude”, EAST],
AXIS[“Geodetic latitude”, NORTH],
PROJECTION[“Polar_Stereographic”, AUTHORITY[“EPSG”,“9810”]],
PARAMETER[“central_meridian”, 18.0],
PARAMETER[“latitude_of_origin”, 90.0],
PARAMETER[“scale_factor”, 0.994],
PARAMETER[“false_easting”, 2000000.0],
PARAMETER[“false_northing”, 2000000.0],
UNIT[“m”, 1.0],
AXIS[“Easting”, “South along 108 deg East”],
AXIS[“Northing”, “South along 162 deg West”],

Thank you in advance.

Have you looked at Cartopy Issues for discussion of
Polar Stereographic Projections?

I think cartopy relies on the PROJ and GDAL libraries (as does SNAP, but SNAP is further removed from the upstream sources so lags behind cartopy). I recall discussions of recent improvements to the support for mapping polar regions. You could start by checking support in current versions of PROJ and GDAL. Quoting man projinfo for PROJ8.2:

projinfo is a program that can query information on a geodetic object, coordinate reference system
(CRS) or coordinate operation, when the -s and -t options are specified, and display it under dif‐
ferent formats (PROJ string, WKT string or PROJJSON string).

It can also be used to query coordinate operations available between two CRS.

The program is named with some reference to the GDAL gdalsrsinfo that offers partly  similar  services.