The development of a video-level controller for an ultra-violet intensified CCD camera

Requirements exist for measurement of the spatial distribution of ultra-violet (UV) radiation emitted from plumes and combustion systems. An imaging camera sensitive in the UV and capable of determining absolute intensity is necessary to make such measurements. This thesis describes the development of the video-level controller necessary to transform an existing UV intensified charge-coupled device (CCD) camera into a camera capable of determining absolute intensity over a wide dynamic range. An image intensifier inside the camera converts the UV image into a visible image and the CCD camera transforms the visible image into a standard video signal. By controlling electrical inputs to the image intensifier, it is possible to vary the intensity of the visible output image. An intelligent electronic controller, using high-speed digital hardware, is developed to sample the video from the CCD camera and adjust the intensifier gain to maintain a one-volt nominal output level from the camera. The auto-ranging process is designed to converge rapidly on transient data. As a result, the video signal always remains on scale and the system's instantaneous sensitivity is always known. By recording intensifier gain with the video, isoradiance contours and other useful images can be produced.