def get_shapes_F1(F1):
    """
    Get string showing shapes of F1.
    
    Parameters
    ----------
     F1:    list of multidimensional np.arrays
         (each elment has the samples for each station-poliarization.
     
    Returns
    -------
     out : str
    """
    return(str([(F1[i].shape) for i in range(len(F1))]))