Radar Detection and Recognition of a Hovering Helicopter

The problem of radar detection of a hovering helicopter is considered. A detection algorithm is proposed that implements rejection of the clutter and discrimination of the periodic structure of the signal scattered by the rotating rotor. The algorithm permits to estimate the rotor rotation period. The estimate can be used to identify the type of the helicopter. It is shown that the algorithm is stable when the signal-to-noise ratio is more than 20 dB and the signal-to-clutter ratio is more than -60 dB.