def geopotential_to_geometric(h, r0):
    """ Converts from given geopotential altitude to geometric one.

    Parameters
    ----------
    h: ~astropy.units.Quanity
        Geopotential altitude.
    r0: ~astropy.units.Quantity
        Planet/Natural satellite radius.

    Returns
    -------
    z: ~astropy.units.Quantity
        Geometric altitude.
    """
    z = r0 * h / (r0 - h)
    return z
