Blooming in a Charge-Coupled Device Imager. Blooming Control Recommendations are Given for Low-Light-Level CCD Imagers with Time Delay and Integration, Such as the LOPATCH Sensor.

Low-light-level television LLLTV imagers have an attendant susceptibility to saturation. Because of optical overload when intense sources are encountered in LLL ambients, certain pixels will saturate and spill over into adjacent pixels to cause a spreading or blooming situation. A technique is presented to classify and quantitatively characterize the contribution to blooming attributable to ships lights at sea under very low light levels. The type of imager considered is a CCD charge-coupled device operating in the TDI time delay and integration mode used to enhance signal-to-noise and sensitivity characteristics. Also presented is a means to determine the obscuration which results from blooming when an attempt is made to recognize ships with lights at sea. Finally, obscuration projections are superimposed over typical ships silhouettes to determine to what extent the recognition has been impaired. Conclusions are given concerning the level of blooming control required to meet the detection and recognition requirements in the LOPATCH Low-Light-Level Panoramic TDI-CCD Imaging System. Author