Editing Image intensifier (section)

===Gating===
Electronic Gating (or 'gating') is a means by which an image intensifier tube may be switched ON and OFF in a controlled manner. An electronically gated image intensifier tube functions like a camera shutter, allowing images to pass through when the electronic "gate" is enabled. The gating durations can be very short (nanoseconds or even picoseconds).  This makes gated image intensifier tubes ideal candidates for use in research environments where very short duration events must be photographed. As an example, in order to assist engineers in designing more efficient combustion chambers, gated imaging tubes have been used to record very fast events such as the wavefront of burning fuel in an internal combustion engine.

Often gating is used to synchronize imaging tubes to events whose start cannot be controlled or predicted.  In such an instance, the gating operation may be synchronized to the start of an event using 'gating electronics', e.g. high-speed digital delay generators. The gating electronics allows a user to specify when the tube will turn on and off relative to the start of an event.

There are many examples of the uses of gated imaging tubes. Because of the combination of the very high speeds at which a gated tube may operate and their light amplification capability, gated tubes can record specific portions of a beam of light. It is possible to capture only the portion of light ''reflected'' from a target, when a pulsed beam of light is fired at the target, by controlling the gating parameters. Gated-Pulsed-Active Night Vision (GPANV) devices are another example of an application that uses this technique. GPANV devices can allow a user to see objects of interest that are obscured behind vegetation, foliage, and/or mist. These devices are also useful for locating objects in deep water, where reflections of light off of nearby particles from a continuous light source, such as a high brightness underwater floodlight, would otherwise obscure the image.