def K2(eps):
    """ Radar dielectric factor |K|**2

    Parameters
    ----------
    eps : complex
        nd array of complex relative dielectric constants

    Returns
    -------
    nd - float
        Radar dielectric factor |K|**2 real

    """
    K_complex = (eps-1.0)/(eps+2.0)
    return (K_complex*K_complex.conj()).real