code: def _srads2bt(self, data, channel_name):
          
          a__, b__, c__ = BTFIT[channel_name]
          wavenumber = CALIB[self.platform_id][channel_name]["VC"]
          temp = self._tl15(data, wavenumber)
  
          return a__ * temp * temp + b__ * temp + c__
docs: Computation based on spectral radiance.