| 摘要 |
<p>PURPOSE:To restrain clutter caused by ocean current speed, and detect a very slowly moving target on the sea level by correcting a received signal according to averaged ocean current speed. CONSTITUTION:A signal from an oscillation correcting circuit 33 is delayed until a next reflection signal is received by means of a pulse repetition interval PRI delay circuit 34. When the next reflection signal is outputted from the circuit 33, the circuit 34 outputs a previous received signal, and inputs it to an ocean current speed detecting circuit 35 in the same timing. The circuit 35 detects a phase difference between the received signals corresponding to respective previous and next transmission pulses, that is, a phase rotational quantity of Doppler frequency caused by an ocean current. An ocean current speed averaging circuit 36 averages the number of optional range cells and a phase rotational quantity of the number of pulses, and reduces detection errors. When the first received signal is outputted from a sweep memory circuit 38 after output of the circuit 36 is set in an ocean current speed correcting circuit 37 while using it as ocean current speed on the sea level, ocean current speed correction is carried out on this signal by means of the circuit 37, and it is transmitted to an MTI circuit 39, and a clutter component can be eliminated sufficiently.</p> |
