class_docstr: Get the emissive part of NIR bands.
class_docstr_tok: ["Get","the","emissive","part","of","NIR","bands","."]
docstr: Get the emissivity from pyspectral.
docstr_tok: ["Get","the","emissivity","from","pyspectral","."]
code: def _get_emissivity_as_dask(
      self, da_nir, da_tb11, da_tb13_4, da_sun_zenith, metadata
  ):
      """Get the emissivity from pyspectral."""
      reflectance_3x_calculator = self._init_reflectance_calculator(
          metadata
      )
      # Use the nir and thermal ir brightness temperatures and derive the reflectance using
      # PySpectral. The reflectance is stored internally in PySpectral and
      # needs to be derived first in order to get the emissive part.
      reflectance_3x_calculator.reflectance_from_tbs(
          da_sun_zenith, da_nir, da_tb11, tb_ir_co2=da_tb13_4
      )
      return reflectance_3x_calculator.emissive_part_3x()
  
file_path: satpy/satpy/modifiers/spectral.py
imports: import logging
  import xarray
  from satpy.modifiers import ModifierBase
label_desc: Use image node_id 4 for calling the NIREmissivePartFromReflectance obj's underlying member method code with example usage: obj._get_emissivity_as_dask(da_nir, da_tb11, da_tb13_4, da_sun_zenith, metadata) and returns: reflectance_3x_calculator