def corrected_proj_param(big_H, lil_h, R):
    """
    Eq. 4.11
    Calculates the corrected projection parameter for a cloud target

    Parameters
    ------------
    big_H : int
        Satellite's height above the Earth's surface, in km

    lil_h : int
        Cloud's altitude above the Earth's surface, in km

    R : int
        Earth's radius, in km

    Returns
    ------------
    P_h : float
        Corrected projection parameter
    """
    P_h = (R + big_H) / (R + lil_h)
    return P_h