def METHOD_NAME(self, data):
    """Calibrate IR channels to BT."""
    fk1 = float(self["planck_fk1"])
    fk2 = float(self["planck_fk2"])
    bc1 = float(self["planck_bc1"])
    bc2 = float(self["planck_bc2"])
    if self.clip_negative_radiances:
        min_rad = self._get_minimum_radiance(data)
        data = data.clip(min=min_rad)
    res = (fk2 / np.log(fk1 / data + 1) - bc1) / bc2
    res.attrs = data.attrs
    res.attrs['units'] = 'K'
    res.attrs['long_name'] = 'Brightness Temperature'
    res.attrs['standard_name'] = 'toa_brightness_temperature'
    return res