a method is provide for measuring electromagnetic radiation radiated from a surface of an object that is irradiated by electromagnetic radiation given off by at least one radiation source . the radiation given off by the radiation source is determined by at least one first detector , and the radiation given off by the irradiated object is determined by at least one second detector that measures the radiation . the radiation from the at least one radiation source is actively modulated with at least one characteristic parameter . the radiation determined by the second detector is corrected with the radiation determined by the first detector to compensate for the radiation of the radiation source reflected from the object .