def Calc_NDVI(Reflect):
    """
    This function calculates and returns the Surface albedo, NDVI by using the refectance from the landsat image.
    """
    NDVI = (Reflect[:, :, (3)] - Reflect[:, :, (2)]) / (Reflect[:, :, (3)] +
        Reflect[:, :, (2)])
    return NDVI
