Abstract: The present invention is directed to a method of calibrating a light source. In one embodiment, a standard image sensor is used to capture emitted light of a standard and a to-be-calibrated light source in order to obtain a standard and a nonstandard image, respectively. A standard and a nonstandard luminance response are generated according to the standard and the nonstandard image, respectively. The to-be-calibrated light source is adjusted until the nonstandard luminance response is about equal to the standard luminance response. In another embodiment, the standard image sensor is used to capture emitted light of the standard and the to-be-calibrated light source. According to sampled outputs of the standard image sensor, a standard and a nonstandard chrominance response are respectively generated, which are used to compensate an image sensor under test.

Abstract: Network access providers implement interactive procedures and subscriber terminals employ embedded secure authentication structures and procedures to ensure that a satellite modem at the subscriber terminal accurately verifies the identity of a satellite modem terminal system at the location of the network access provider gateway facility during the satellite modem initialization process so that the satellite modem will only attempt to acquire satellite resource from the appropriate (authenticated and authorized) satellite modem termination system. In a virtual downstream channel environment, diverse downstream channel feeds are distinguished by authentication procedures. The present invention differs from standard theft of service prevention because theft of subscriber prevention is in a virtual channel environment, where subscriber terminals have access to a plurality of virtual channels by the nature of the signal.