| 摘要 |
PURPOSE:To achieve an accurate target extraction preventing misperception of a background noise for the target, by removing a specified frequency component unnecessary for the target extraction with a filter to compare the peak-to- peak value of a filter output signal with the maximum of changes in the time. CONSTITUTION:A filter 44 removes a specified frequency portion from a signal from a radial scanner 7 and detects the maximum value and the time of the hourly change in the signal obtained by converting the output into digital in N bits (N is natural number) with a differentiation coefficient detector 9. A peak detector 37 detects the difference between the maximum and minimum of the signal obtained by converting the signal from a unit 17 to digital in N bits and a lock-on decider 29 compares the output of the detector 37 and the output of the detector 9 and outputs a lock-on signal only when a lock-on is possible. Thus, only when the lock-on signal is outputted, a coordinate converter 11 converts the time outputted from the detector 9 to an X-Y coordinate system to be outputted.
|
