code: def _get_satellite_unit_vector_y(unit_vector_x, unit_vector_z):
      res = cross_product(unit_vector_z, unit_vector_x)
      return normalize_vector(res)
  
imports: from collections import namedtuple
  import dask.array
  import numba
  import numpy
  from satpy.utils import get_legacy_chunk_size
label_desc: Use image node_id 21 for calling a global function with example usage: _get_satellite_unit_vector_y(unit_vector_x, unit_vector_z) and returns: normalize_vector