class_docstr: Get the reflective part of NIR bands.
class_docstr_tok: ["Get","the","reflective","part","of","NIR","bands","."]
docstr: Initialize the 3.x reflectance derivations.
docstr_tok: ["Initialize","the","3.x","reflectance","derivations","."]
code: def _init_reflectance_calculator(self, metadata):
      """Initialize the 3.x reflectance derivations."""
      if not Calculator:
          logger.info("Couldn't load pyspectral")
          raise ImportError(
              "No module named pyspectral.near_infrared_reflectance"
          )
  
      reflectance_3x_calculator = Calculator(
          metadata["platform_name"],
          metadata["sensor"],
          metadata["name"],
          sunz_threshold=self.sun_zenith_threshold,
          masking_limit=self.masking_limit,
      )
      return reflectance_3x_calculator
  
file_path: satpy/satpy/modifiers/spectral.py
imports: import logging
  import xarray
  from satpy.modifiers import ModifierBase
label_desc: Use image node_id 9 for calling the NIRReflectance obj's underlying member method code with example usage: obj._init_reflectance_calculator(metadata) and returns: reflectance_3x_calculator