class_docstr: SEVIRI HRIT prologue reader.
class_docstr_tok: ["SEVIRI","HRIT","prologue","reader","."]
docstr: Get actual satellite position in geodetic coordinates (WGS-84).
  
  Evaluate orbit polynomials at the start time of the scan.
  
  Returns: Longitude [deg east], Latitude [deg north] and Altitude [m]
code: def satpos(self):
      """Get actual satellite position in geodetic coordinates (WGS-84).
  
      Evaluate orbit polynomials at the start time of the scan.
  
      Returns: Longitude [deg east], Latitude [deg north] and Altitude [m]
      """
      a, b = self.get_earth_radii()
      poly_finder = OrbitPolynomialFinder(
          self.prologue["SatelliteStatus"]["Orbit"]["OrbitPolynomial"]
      )
      orbit_polynomial = poly_finder.get_orbit_polynomial(
          self.observation_start_time
      )
      return get_satpos(
          orbit_polynomial=orbit_polynomial,
          time=self.observation_start_time,
          semi_major_axis=a,
          semi_minor_axis=b,
      )
  
imports: from __future__ import division
  import copy
  import logging
  from datetime import timedelta
  import dask.array
  import numpy
  import xarray
  from pyresample import geometry
  import satpy.readers.utils
  from satpy._compat import cached_property
  from satpy.readers._geos_area import get_area_definition, get_area_extent, get_geos_area_naming
  from satpy.readers.eum_base import get_service_mode, recarray2dict, time_cds_short
  from satpy.readers.hrit_base import HRITFileHandler, ancillary_text, annotation_header, base_hdr_map, image_data_function
  from satpy.readers.seviri_base import CHANNEL_NAMES, HRV_NUM_COLUMNS, REPEAT_CYCLE_DURATION, SATNUM, NoValidOrbitParams, OrbitPolynomialFinder, SEVIRICalibrationHandler, add_scanline_acq_time, create_coef_dict, get_cds_time, get_satpos, mask_bad_quality, pad_data_horizontally, round_nom_time
  from satpy.readers.seviri_l1b_native_hdr import hrit_epilogue, hrit_prologue, impf_configuration
  from satpy.utils import get_legacy_chunk_size
label_desc: Use image node_id 3 for calling the HRITMSGPrologueFileHandler obj's underlying member method code with example usage: obj.satpos() and returns: get_satpos