def reflection_constant(ground_reflections: bool) -> float:
    """Utility function to calculate a factor that describes how much RF is increased by ground reflection.

    :param ground_reflections: Whether ground reflections are present
    :return: Coefficient (dimensionless) that other functions use to multiply EIRP
    :raises ValueError: if ground_reflections is not bool
    """
    if type(ground_reflections) != bool:
        raise ValueError("ground_reflections must be boolean: %s" % str(ground_reflections))
    if not ground_reflections:
        return 1
    else:
        return 1.6 * 1.6