code: def get_geostationary_angle_extent(geos_area):
      
      # TODO: take into account sweep_axis_angle parameter
  
      # get some projection parameters
      req = geos_area.proj_dict['a'] / 1000
      rp = geos_area.proj_dict['b'] / 1000
      h = geos_area.proj_dict['h'] / 1000 + req
  
      # compute some constants
      aeq = 1 - req**2 / (h ** 2)
      ap_ = 1 - rp**2 / (h ** 2)
  
      # generate points around the north hemisphere in satellite projection
      # make it a bit smaller so that we stay inside the valid area
      xmax = np.arccos(np.sqrt(aeq))
      ymax = np.arccos(np.sqrt(ap_))
      return xmax, ymax
docs: Get the max earth (vs space) viewing angles in x and y.