| 摘要 |
<p>PURPOSE:To prevent a generation of erroneous detection by performing a process of Rayleigh constant false alarm rate(CFAR) at the normal time and changing it over to a sequential statistics type CFAR process at the condition when approaching plural targets are in existence. CONSTITUTION:A receiving signal of radar is inputted to a sequential statistics type CFAR circuit 1 and a Rayleigh CFAR circuit 2 after a pre-process such as a clatter suppressing, etc., is performed. In the circuit 2, the process is occasionally mismade as no target existed in spite of when the target is in existence under the condition of approaching plural targets, since the threshold is calculated with the use of amplitude data of overall range bin of a reference cell. On the contrary, in the circuit 1, the approaching targets are properly detected because the threshold is calculated by omitting the maximum value or plural values from the larger values side including the maximum value among the data of reference cell. Consequently, in a plural targets decision circuit 3, an output of the circuit 1 is selected as the result of a detection circuit by controlling a selection circuit 4 when the plural approaching targets are decided to be existed by the output of circuit 1, and in the cases other than the above, an output of the circuit 2 having a small CFAR loss is selected.</p> |
