class_docstr: Shared operations for file handlers.
class_docstr_tok: ["Shared","operations","for","file","handlers","."]
docstr: Return longitude at subsatellite point.
docstr_tok: ["Return","longitude","at","subsatellite","point","."]
code: def ssp_lon(self):
      """Return longitude at subsatellite point."""
      try:
          return float(
              self.nc["mtg_geos_projection"].attrs[
                  "longitude_of_projection_origin"
              ]
          )
      except (KeyError, AttributeError):
          logger.warning(
              f"ssp_lon could not be obtained from file content, using default value "
              f"of {SSP_DEFAULT} degrees east instead"
          )
          return SSP_DEFAULT
  
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 3 for calling the FciL2CommonFunctions obj's underlying member method code with example usage: obj.ssp_lon() and returns: float, SSP_DEFAULT