초록 ▼

A clutter tracking and cancelling system, for use in a MTI radar system, comprising an auxiliary channel consisting primarily of a phase detector and a canceller. The phase detector provides an output which represents the phase difference between the IF and the coho output, while the output of the c

A clutter tracking and cancelling system, for use in a MTI radar system, comprising an auxiliary channel consisting primarily of a phase detector and a canceller. The phase detector provides an output which represents the phase difference between the IF and the coho output, while the output of the canceller, which responds to the phase detector output, represents clutter MTI residue from one transmission to the next. Clutter MTI residue from several successive range bins is smoothed and integrated to provide a control output which is used to shift the phase of the coho frequency, which is supplied to the phase detector in the conventional main MTI channel, to set the mean clutter velocity at zero velocity in order to produce optimum clutter cancellation in the main MTI channel.

대표청구항 ▼

In a moving target indication radar system of the type including means for transmitting energy of a predetermined frequency which is reflected by targets including clutter, means for receiving said reflected energy, a coherent source of energy of a fixed frequency, means for converting the reflected

In a moving target indication radar system of the type including means for transmitting energy of a predetermined frequency which is reflected by targets including clutter, means for receiving said reflected energy, a coherent source of energy of a fixed frequency, means for converting the reflected energy into intermediate frequency signals from each of a succession of range bins from which said energy was reflected, a main phase detector to which said intermediate frequency signals and the energy from said coherent source are applied and a main canceller for providing an output representing moving-target-indication residue from one transmission to the next, a clutter detection and cancelling system comprising: a moving target indication clutter channel responsive to said intermediate frequency signals and to said coherent energy for providing a clutter moving target indication residue for each range bin from transmission to transmission; and control means responsive to said clutter residue for controlling the phase of the energy from said coherent source which is applied to the main phase detector.