reads the solar limb template file and adjust to the requested solar diameter
        :param diam_sun: diameter of sun in suvi pixels
        :param base_shape: the shape of a suvi image
        :return: product name, None, scaled image

def fetch_limb(self, diam_sun, base_shape=(1280, 1280)):
        """
        reads the solar limb template file and adjust to the requested solar diameter
        :param diam_sun: diameter of sun in suvi pixels
        :param base_shape: the shape of a suvi image
        :return: product name, None, scaled image
        """
        from scipy.ndimage.interpolation import zoom

        fn = pkg_resources.resource_filename("suvitrainer", "path_length_280_noisy.fits")
        calculated_diam = int(os.path.basename(fn).split("_")[2]) * 2
        with fits.open(fn) as hdus:
            limb_unscaled = hdus[0].data
        scale_factor = diam_sun / calculated_diam
        limb_scaled = zoom(limb_unscaled, scale_factor)
        shape = limb_scaled.shape[0]
        excess = int((shape - base_shape[0]) / 2.0)
        limb_scaled = limb_scaled[excess:shape - excess, excess:shape - excess]
        limb_scaled = limb_scaled[0:base_shape[0], 0:base_shape[1]]
        return "limb", None, limb_scaled