class_docstr: SEVIRI calibration algorithms.
class_docstr_tok: ["SEVIRI","calibration","algorithms","."]
docstr: Convert effective radiance to brightness temperature.
docstr_tok: ["Convert","effective","radiance","to","brightness","temperature","."]
code: def _erads2bt(self, data, channel_name):
      """Convert effective radiance to brightness temperature."""
      cal_info = CALIB[self._platform_id][channel_name]
      alpha = cal_info["ALPHA"]
      beta = cal_info["BETA"]
      wavenumber = CALIB[self._platform_id][channel_name]["VC"]
  
      return (self._tl15(data, wavenumber) - beta) / alpha
  
imports: from __future__ import annotations
  import warnings
  from datetime import datetime, timedelta
  import dask.array
  import numpy
  import pyproj
  from numpy.polynomial.chebyshev import Chebyshev
  from satpy.readers.eum_base import issue_revision, time_cds_short
  from satpy.readers.utils import apply_earthsun_distance_correction
  from satpy.utils import get_legacy_chunk_size
label_desc: Use image node_id 3 for calling the SEVIRICalibrationAlgorithm obj's underlying member method code with example usage: obj._erads2bt(data, channel_name) and returns: unknown