def apparent_elevation_approximate(theta_true, height):
    """
    Calculate the apparent elevation angle with the approximate equation.
    :param theta_true: The true elevation angle (degrees).
    :param height: The height of the radar (km).
    :return: The approximated apparent elevation angle (degrees).
    """
    angle_correction = 1. / (1.728 + 0.5411 * theta_true + 0.03723 * theta_true**2 +
                             height * (0.1815 + 0.06272 * theta_true + 0.01380 * theta_true**2) +
                             height**2 * (0.01727 + 0.008288 * theta_true))

    return theta_true + angle_correction