def _clean_pixel(_ds, saturation_threshold=10000):
    """Filters out over-saturated values

    Creates a mask from the saturation threshold and > 0 and applies it to _ds.

    Args:
        _ds: dataset to mask
        saturation_threshold: threshold that a pixel must be below to be considered 'clean'

    Returns:
        an xArray dataset that has been masked for saturation and valid (>0) pixels
    """
    ds = _ds
    mask = (ds < saturation_threshold) & (ds >= 0)
    indices = [x for x, y in enumerate(mask.red.values) if y == True]
    return ds.isel(time=indices)