Spectral Subtraction: A New Approach to Remove Low- and High-Order Speckle Noise

摘要: We present a novel "spectral subtraction algorithm" (SSA) technique to remove speckle noise. It consists of low-order and high-order SSA is based on three-dimensional image spectroscopy in which the data cube available thus noise introduced by wave-front error can be efficiently subtracted. For SSA, speckles up second or third order totally subtracted, leaving residual dominated only fourth order, respectively, imaging contrast increased consequently; for fifth sixth performance further improved. This first demonstration that such could Since SSAs are conducted over wide spectral band, white-light re-assembled from cube. The would increase single-to-noise ratio reduce exposure time, crucial search faint companion objects. Combined with coronagraph, provide an extra gain coronagraph imaging, relax requirement quality (no adaptive optics correction required space-borne system), significantly exoplanet biomarker spectroscopy.