The combined effect of airframe shape and RAM of the production aircraft is estimated to have reduced the aircraft's RCS to a value thirty times smaller than that of the Su-27. Sukhoi's patent for the T-50 prototype stealth features cites an intention to reduce average RCS to approximately 0.1 to 1 m2, compared to the Su-27's RCS of approximately 10 to 15 m2. Like other stealth fighters, the Su-57's low observability measures are chiefly effective against high-frequency (between 3 and 30 GHz) radars, usually found on other aircraft. The effects of Rayleigh scattering and resonance mean that low-frequency radars, employed by weather radars and early-warning radars are more likely to detect the Su-57 due to its size. Such radars are also large, susceptible to clutter and are less precise.