Moving target indication
(重定向自GMTI)

Moving target indication (MTI) is a mode of operation of a radar to discriminate a target against the clutter.
In contrast to another mode, stationary target indication, it takes advantage of the fact that the target moves with respect to stationary clutter. The most common approach takes advantage of the Doppler effect. For a given sequence of radar pulses, the moving target will change its distance from the radar system. Therefore, the phase of the radar reflection that returns from the target will be different for successive pulses. This differs from a stationary target (or clutter) which will cause the reflected pulses to arrive at the same phase.