class_docstr: Reader class for FCI L2 products in NetCDF4 format.
class_docstr_tok: ["Reader","class","for","FCI","L2","products","in","NetCDF4","format","."]
docstr: Extract projection and area information.
docstr_tok: ["Extract","projection","and","area","information","."]
code: def _get_proj_area(self, dataset_id):
      """Extract projection and area information."""
      # Read the projection data from the mtg_geos_projection variable
      a = float(self._projection.attrs["semi_major_axis"])
      h = float(self._projection.attrs["perspective_point_height"])
  
      # Some L2PF test data files have a typo in the keyname for the inverse flattening parameter. Use a default value
      # as fallback until all L2PF test files are correctly formatted.
      rf = float(
          self._projection.attrs.get(
              "inverse_flattening", 298.257223563
          )
      )
  
      res = dataset_id["resolution"]
  
      area_naming_input_dict = {
          "platform_name": "mtg",
          "instrument_name": "fci",
          "resolution": res,
      }
  
      area_naming = get_geos_area_naming(
          {
              **area_naming_input_dict,
              **get_service_mode("fci", self.ssp_lon),
          }
      )
  
      proj_dict = {
          "a": a,
          "lon_0": self.ssp_lon,
          "h": h,
          "rf": rf,
          "proj": "geos",
          "units": "m",
          "sweep": "y",
      }
  
      return area_naming, proj_dict
  
imports: import logging
  from contextlib import suppress
  import numpy
  import xarray
  from pyresample import geometry
  from satpy._compat import cached_property
  from satpy.readers._geos_area import get_geos_area_naming, make_ext
  from satpy.readers.eum_base import get_service_mode
  from satpy.readers.file_handlers import BaseFileHandler
  from satpy.resample import get_area_def
  from satpy.utils import get_legacy_chunk_size
label_desc: Use image node_id 7 for calling the FciL2NCFileHandler obj's underlying member method code with example usage: obj._get_proj_area(dataset_id) and returns: area_naming,  proj_dict