class_docstr: SEVIRI calibration algorithms.
class_docstr_tok: ["SEVIRI","calibration","algorithms","."]
docstr: Calibrate to brightness temperature.
docstr_tok: ["Calibrate","to","brightness","temperature","."]
code: def ir_calibrate(self, data, channel_name, cal_type):
      """Calibrate to brightness temperature."""
      if cal_type == 1:
          # spectral radiances
          return self._srads2bt(data, channel_name)
      elif cal_type == 2:
          # effective radiances
          return self._erads2bt(data, channel_name)
      else:
          raise NotImplementedError("Unknown calibration type")
  
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 4 for calling the SEVIRICalibrationAlgorithm obj's underlying member method code with example usage: obj.ir_calibrate(data, channel_name, cal_type) and returns: self, self