code: def _ir_calibrate(self, data, channel_name, cal_type):
          
          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')
docs: Calibrate to brightness temperature.