Interframe Processing the Sequence of Images Obtained Using Scanning PD Having Spatially Uneven Sensitivity

Sensitivity alignment, based on preliminary calibration, is the technique used to improve the operational parameters in multielement photodetectors having spatially uneven sensitivity. This calibration should be repeated from time to time during operations to take care of drifting the detectors parameters. The experts are interested specifically in calibrating and correcting techniques that do not require the standard light source. The method proposed to evaluate and correct uneven sensitivity in scanning photodetectors is aimed at reducing effect of interference on interframe processing. It is based on analyzing an image pair obtained through shifting the photodetector and the scene recorded. When the image shift is known for columns situated in the image overlap area, an underdetermined system of equations can be developed and solved using the least square technique. A method for correcting the solution error caused by the system underdefiniteness is presented. A numerical simulation confirms the efficiency of the method to suppress interframe background and detect moving small objects.