Patent ID: 7541567

Claim:
An apparatus for validating a photometric sensor, the apparatus comprising: a photometric sensor having a plurality of pixels that receives a series of electromagnetic signals wherein at least a portion of each electromagnetic signal is distributed over two or more pixels and wherein each portion of each electromagnetic signal associated with a particular pixel has a corresponding intensity; a photometric sensor interface circuit that assesses intensity variations in the received portions of the electromagnetic signals distributed over various pixels on a pixel-by-pixel basis and approximates a noise level and an illumination level based on the intensity variations to determine the operating characteristics of the photometric sensor; and a memory coupled to the photometric sensor interface circuit, the memory comprising machine readable instructions comprising: read instructions for reading a plurality of varying brightness readings for the various pixels in the plurality of photosensitive pixels; noise determination instructions for calculating statistical dispersions for the plurality of varying brightness readings for the various pixels; stable intensity determination instructions for calculating stable intensity values for the plurality of varying brightness readings for the various pixels; photon transfer curve approximation instructions for approximating a photon transfer curve corresponding to the photometric sensor based on the statistical dispersions and the stable intensity values, and operational indication instructions to indicate whether the photometric detector is operating properly based on the photon transfer curve.