code: def radar_xsect(scatterer, h_pol=True):
      
      Z = scatterer.get_Z()
      if h_pol:
          return 2 * np.pi * \
              (Z[0,0] - Z[0,1] - Z[1,0] + Z[1,1])
      else:
          return 2 * np.pi * \
              (Z[0,0] + Z[0,1] + Z[1,0] + Z[1,1])
docs: Radar cross section for the current setup.    
  
      Args:
          scatterer: a Scatterer instance.
          h_pol: If True (default), use horizontal polarization.
          If False, use vertical polarization.
  
      Returns:
          The radar cross section.