Sensor system

Abstract

The invention provides a sensor system ( ) for generating a sensor signal (S ) corresponding to a filtered image of a scene. The system ( ) incorporates a multielement array ( ) and associated processing circuits for providing element signals in response to images projected onto it and a projecting lens assembly ( ) for projecting images onto the array ( ). The lens assembly ( ) projects differently blurred images of the scene onto the array ( ) for generating a measurement signal during a measurement phase and a local spatial average correction signal during a calibration phase. A light-diffusing shutter ( ) is used for generating the differently blurred images. The system ( ) substracts the measurement and correction signals of each element from one another to provide a difference signal and uses this signal to generate the sensor signal (S ) during the measurement phase. The calibration phase is repeated on change of array temperature or incident radiation intensity, thereby reducing fixed pattern noise in the sensor signal (S ) despite environmental change, and interrupting the measurement phase only infrequently.