def filter_saturated(observations):
    """
    bool index for unsaturated obserervations between 0..10,000

    Useful for efficiently filtering noisy-data from arrays.

    Arguments:
        observations: spectra nd-array, assumed to be shaped as
            (6,n-moments) of unscaled data.
            
    Returns:
        1-d bool ndarray

    """
    unsaturated = ((0 < observations[1, :]) & (observations[1, :] < 10000) &
                   (0 < observations[2, :]) & (observations[2, :] < 10000) &
                   (0 < observations[3, :]) & (observations[3, :] < 10000) &
                   (0 < observations[4, :]) & (observations[4, :] < 10000) &
                   (0 < observations[5, :]) & (observations[5, :] < 10000) &
                   (0 < observations[0, :]) & (observations[0, :] < 10000))
    return unsaturated